From gordonjcp at gjcp.net  Thu Aug  1 22:58:13 2024
From: gordonjcp at gjcp.net (Gordonjcp)
Date: Thu, 1 Aug 2024 21:58:13 +0100
Subject: [sdiy] Synth meetups and must-see shops in Vienna?
Message-ID: <20240801205813.GA24169@gjcp.net>

Hi folks, 

As the subject says, does anyone know if there are any synth meetups in Vienna, or any particular shops, museums, or other interesting places I should visit while I'm here?

I've already got Flash and Klangfarbe on my list :-)

-- 
Gordonjcp

From mbryant at futurehorizons.com  Thu Aug  1 23:49:37 2024
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Thu, 1 Aug 2024 21:49:37 +0000
Subject: [sdiy] Synth meetups and must-see shops in Vienna?
In-Reply-To: <20240801205813.GA24169@gjcp.net>
References: <20240801205813.GA24169@gjcp.net>
Message-ID: <CWLP265MB7132CCB1C4AE6ADF12BADDCFDBB22@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

Well it's not quite a synth, but the grand organ in the Vienna Konzerthaus is the largest in Europe with so many stops it rivals any additive synth.  I believe there's a schedule on when there are recitals on it at lunchtimes.

________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Gordonjcp <gordonjcp at gjcp.net>
Sent: 01 August 2024 21:58
To: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: [sdiy] Synth meetups and must-see shops in Vienna?

Hi folks,

As the subject says, does anyone know if there are any synth meetups in Vienna, or any particular shops, museums, or other interesting places I should visit while I'm here?

I've already got Flash and Klangfarbe on my list :-)

--
Gordonjcp
________________________________________________________
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Submit email to: Synth-diy at synth-diy.org
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From maffezsynthmods at gmail.com  Fri Aug  2 09:15:25 2024
From: maffezsynthmods at gmail.com (Maffez Synthmods)
Date: Fri, 2 Aug 2024 09:15:25 +0200
Subject: [sdiy] Synth meetups and must-see shops in Vienna?
In-Reply-To: <CWLP265MB7132CCB1C4AE6ADF12BADDCFDBB22@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <20240801205813.GA24169@gjcp.net>
 <CWLP265MB7132CCB1C4AE6ADF12BADDCFDBB22@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <CAKN+41wO9qHi6FZA5d9SbhsS7brwnCmdsqjBBg-5JKxWy6GGig@mail.gmail.com>

Signal Zirkus have regular meetups. Not sure when their next one is though.

https://www.instagram.com/signal_zirkus/

https://www.facebook.com/SignalZirkus/?locale=de_DE

Am Do., 1. Aug. 2024 um 23:53 Uhr schrieb Mike Bryant <
mbryant at futurehorizons.com>:

> Well it's not quite a synth, but the grand organ in the Vienna Konzerthaus
> is the largest in Europe with so many stops it rivals any additive synth.
> I believe there's a schedule on when there are recitals on it at lunchtimes.
>
> ------------------------------
> *From:* Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of
> Gordonjcp <gordonjcp at gjcp.net>
> *Sent:* 01 August 2024 21:58
> *To:* synth-diy at synth-diy.org <synth-diy at synth-diy.org>
> *Subject:* [sdiy] Synth meetups and must-see shops in Vienna?
>
> Hi folks,
>
> As the subject says, does anyone know if there are any synth meetups in
> Vienna, or any particular shops, museums, or other interesting places I
> should visit while I'm here?
>
> I've already got Flash and Klangfarbe on my list :-)
>
> --
> Gordonjcp
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From btremblay at me.com  Sun Aug  4 19:13:42 2024
From: btremblay at me.com (Benjamin Tremblay)
Date: Sun, 4 Aug 2024 13:13:42 -0400
Subject: [sdiy] using a dac as a digitally controlled amplifier
Message-ID: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>

Is there any practical application for synthesizers to pass an analog signal in as a reference voltage to a DAC?
12 bit DACs are pretty cheap these days, but VCAs aren?t expensive either. 
Aside from cost, why would I want to use a DAC as a ?DCA?? 

I can imagine making a state variable filter using a dual DAC as the ?gain' stages.  
It?s the kind of thing I would try just to see how well it worked? 
 
I suppose you inject one or more DACs into an oscillator to directly control pitch and waveform, some kind of DCO where stability and simplicity are cost-effective. 




From modular at go2.pl  Sun Aug  4 19:20:02 2024
From: modular at go2.pl (Roman Sowa)
Date: Sun, 4 Aug 2024 19:20:02 +0200
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
Message-ID: <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>

One vintage example is FM in Oberheim Matrix synths.
You get precision and repetitive stable amplitude needed for FM.

Roman

W dniu 2024-08-04 o?19:13, Benjamin Tremblay via Synth-diy pisze:
> Is there any practical application for synthesizers to pass an analog signal in as a reference voltage to a DAC?
> 12 bit DACs are pretty cheap these days, but VCAs aren?t expensive either.
> Aside from cost, why would I want to use a DAC as a ?DCA??
>
> I can imagine making a state variable filter using a dual DAC as the ?gain' stages.
> It?s the kind of thing I would try just to see how well it worked?
>   
> I suppose you inject one or more DACs into an oscillator to directly control pitch and waveform, some kind of DCO where stability and simplicity are cost-effective.
>
>
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org


From tom at electricdruid.net  Sun Aug  4 19:26:06 2024
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sun, 4 Aug 2024 18:26:06 +0100
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
Message-ID: <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>

The Synclavier used DACs for VCAs like this too, fed with audio from other DACs. In that case it was a way of avoiding doing multiplies in hardware and not losing any resolution.

> On 4 Aug 2024, at 18:20, Roman Sowa via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> One vintage example is FM in Oberheim Matrix synths.
> You get precision and repetitive stable amplitude needed for FM.
> 
> Roman
> 
> W dniu 2024-08-04 o 19:13, Benjamin Tremblay via Synth-diy pisze:
>> Is there any practical application for synthesizers to pass an analog signal in as a reference voltage to a DAC?
>> 12 bit DACs are pretty cheap these days, but VCAs aren?t expensive either.
>> Aside from cost, why would I want to use a DAC as a ?DCA??
>> 
>> I can imagine making a state variable filter using a dual DAC as the ?gain' stages.
>> It?s the kind of thing I would try just to see how well it worked?
>>  I suppose you inject one or more DACs into an oscillator to directly control pitch and waveform, some kind of DCO where stability and simplicity are cost-effective.
>> 
>> 
>> 
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org



From gordonjcp at gjcp.net  Sun Aug  4 20:43:43 2024
From: gordonjcp at gjcp.net (Gordonjcp)
Date: Sun, 4 Aug 2024 19:43:43 +0100
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
Message-ID: <20240804184343.GA11048@gjcp.net>

On Sun, Aug 04, 2024 at 06:26:06PM +0100, Tom Wiltshire wrote:
> The Synclavier used DACs for VCAs like this too, fed with audio from other DACs. In that case it was a way of avoiding doing multiplies in hardware and not losing any resolution.
> 

The Ensoniq DOC chip uses the same trick for the same reason.

-- 
Gordonjcp


From chris at chrismusic.de  Sun Aug  4 20:49:42 2024
From: chris at chrismusic.de (chris)
Date: Sun, 04 Aug 2024 20:49:42 +0200
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
Message-ID: <20240804204000.17BE.CHRIS@chrismusic.de>

The problem with that may be that (AFAIK) multiplying DACs only multiply
unsigned values.

I once did a crude attempt with an MCP4922 (two multiplying 12 bit DACs).
I level shifted the input so that ground level was at 2.5V. Varying the
DAC value also shifts 2.5 input ground level. 
IIRC, I usedone channel for variable level shifting. 
Messy

Could be possible with a DC offset and AC coupling after the DAC

Chris



On Sun, 4 Aug 2024 13:13:42 -0400 Benjamin Tremblay via Synth-diy
<synth-diy at synth-diy.org> wrote:

> Is there any practical application for synthesizers to pass an analog signal in as a reference voltage to a DAC?
> 12 bit DACs are pretty cheap these days, but VCAs aren?t expensive either. 
> Aside from cost, why would I want to use a DAC as a ?DCA?? 
> 
> I can imagine making a state variable filter using a dual DAC as the ?gain' stages.  
> It?s the kind of thing I would try just to see how well it worked? 
>  
> I suppose you inject one or more DACs into an oscillator to directly control pitch and waveform, some kind of DCO where stability and simplicity are cost-effective. 


From ben at audio.computer  Sun Aug  4 20:58:37 2024
From: ben at audio.computer (Ben Walker)
Date: Sun, 04 Aug 2024 19:58:37 +0100
Subject: [sdiy] Arp Quartet ADSR issues
Message-ID: <275a2f12-b966-41e9-b3d8-88735efbd678@app.fastmail.com>

I?m fixing up an Arp Quartet that I got from eBay in a pretty bad condition. I?ve replaced a bunch of chips that were fried, repaired a broken ground trace on the filter board, and now it?s making some good noises. But there?s still something not right, and I can?t get my head around how it?s supposed to work from the schematic <https://www.polynominal.com/siel-orchestra/ARP%20Quartet%20Service%20Manual.pdf>.

- The brass sound works, but the attack is always short and the decay always (very) long
- The piano sound works
- The organ sound doesn?t work (no output)
- The string sound only works when ?percussion? is engaged.

There?s obviously something wrong with the ADSR circuit. There are a couple of parts of that circuit (Board B, pp. 3-4 of the schematic) that are switched in and out by a 4016 quad switch, which explains why some sounds work (brass, strings + percussion and piano all enable the same bit of circuitry).

The KYBD GATE signal that is sent to the keyboard bus bar sits around +5V for the working sounds, and close to 0V for the others. So there?s no voltage hitting the input pin of the TDA1008, and therefore no output.

The ADSR signal just sits at +6V no matter what the setting or whether a key is pressed, which might explain the lack of working attack/decay

Does anyone have experience with the Quartet, or is anyone able to interpret the schematic and take a guess at which part is not doing its job?

Thanks,

Ben
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From tom at electricdruid.net  Sun Aug  4 23:33:34 2024
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sun, 4 Aug 2024 22:33:34 +0100
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <20240804204000.17BE.CHRIS@chrismusic.de>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <20240804204000.17BE.CHRIS@chrismusic.de>
Message-ID: <404A96FF-A7AC-4692-9E13-19166B0F456D@electricdruid.net>

I've done similar things using unipolar multiplying DACs (MDAC) to fake a genuine bipolar MDAC. I was generating a digital LFO signal, and then using the DAC to control the LFO Depth. Clearly, changing the depth changes the LFO offset, but if you feed half the LFO Depth CV to a differential amp along with the DAC output, it will correct the shifting offset.

 Much simpler for audio is to get a proper bipolar MDAC. They do exist. Multiplying DACs don't *only* deal with unsigned values, just "often".

> On 4 Aug 2024, at 19:49, chris <chris at chrismusic.de> wrote:
> 
> The problem with that may be that (AFAIK) multiplying DACs only multiply
> unsigned values.
> 
> I once did a crude attempt with an MCP4922 (two multiplying 12 bit DACs).
> I level shifted the input so that ground level was at 2.5V. Varying the
> DAC value also shifts 2.5 input ground level. 
> IIRC, I usedone channel for variable level shifting. 
> Messy
> 
> Could be possible with a DC offset and AC coupling after the DAC
> 
> Chris
> 
> 
> 
> On Sun, 4 Aug 2024 13:13:42 -0400 Benjamin Tremblay via Synth-diy
> <synth-diy at synth-diy.org> wrote:
> 
>> Is there any practical application for synthesizers to pass an analog signal in as a reference voltage to a DAC?
>> 12 bit DACs are pretty cheap these days, but VCAs aren?t expensive either. 
>> Aside from cost, why would I want to use a DAC as a ?DCA?? 
>> 
>> I can imagine making a state variable filter using a dual DAC as the ?gain' stages.  
>> It?s the kind of thing I would try just to see how well it worked? 
>> 
>> I suppose you inject one or more DACs into an oscillator to directly control pitch and waveform, some kind of DCO where stability and simplicity are cost-effective. 
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org



From synthdiy at adambaby.com  Mon Aug  5 00:04:56 2024
From: synthdiy at adambaby.com (Adam (synthDIY))
Date: Mon, 5 Aug 2024 08:04:56 +1000
Subject: [sdiy] Arp Quartet ADSR issues
In-Reply-To: <275a2f12-b966-41e9-b3d8-88735efbd678@app.fastmail.com>
References: <275a2f12-b966-41e9-b3d8-88735efbd678@app.fastmail.com>
Message-ID: <2097A61E-0C60-4919-A281-972D23CFAEA0@adambaby.com>



> On 5 Aug 2024, at 4:58?AM, Ben Walker <ben at audio.computer> wrote:
> 
> 
> The KYBD GATE signal that is sent to the keyboard bus bar sits around +5V for the working sounds, and close to 0V for the others. So there?s no voltage hitting the input pin of the TDA1008, and therefore no output.
> 
Are you saying that the presence of the keyboard gate voltage is determined by which sound group you select from the front panel?
That seems like an odd arrangement!
That certainly needs more investigation!
A
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From mr at analogue.org  Mon Aug  5 00:23:20 2024
From: mr at analogue.org (Mattias Rickardsson)
Date: Mon, 5 Aug 2024 00:23:20 +0200
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <20240804184343.GA11048@gjcp.net>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
Message-ID: <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>

Interesting thread.

Do these vintage examples use static amplification factors in their MDACs,
or do they allow the digital value be modulated by envelopes and LFOs?

If they do modulate stuff, how is the result in terms of zipper noise etc?
Unlike when using a VCA controlled by a CV generated from the very same
DAC, there is no way of smoothing out the digital irregularities in the
MDAC case. Only perhaps keeping the sample rate above audio (which they
probably didn't do by then) or to use clever noise shaping techniques
(which also seems unlikely).

/mr

Den s?n 4 aug. 2024 20:48Gordonjcp <gordonjcp at gjcp.net> skrev:

> On Sun, Aug 04, 2024 at 06:26:06PM +0100, Tom Wiltshire wrote:
> > The Synclavier used DACs for VCAs like this too, fed with audio from
> other DACs. In that case it was a way of avoiding doing multiplies in
> hardware and not losing any resolution.
> >
>
> The Ensoniq DOC chip uses the same trick for the same reason.
>
> --
> Gordonjcp
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From tom at electricdruid.net  Mon Aug  5 00:39:25 2024
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sun, 4 Aug 2024 23:39:25 +0100
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
 <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
Message-ID: <80B83CBF-52BA-45D8-BC70-D32F0BEF89E9@electricdruid.net>

The Synclavier used an 8-bit MDAC for the volume envelope, and another for the overall level, I think. The digital stepping intrinsic in this process is now a cherished part of the character of the sound!

The Synclavier used a 50KHz sample rate, but I have no idea if that applied to the envelopes too. It may have done. It was a heavily "overbuilt" machine in many ways, and the price reflected that.

> On 4 Aug 2024, at 23:23, Mattias Rickardsson <mr at analogue.org> wrote:
> 
> Interesting thread.
> 
> Do these vintage examples use static amplification factors in their MDACs, or do they allow the digital value be modulated by envelopes and LFOs?
> 
> If they do modulate stuff, how is the result in terms of zipper noise etc? Unlike when using a VCA controlled by a CV generated from the very same DAC, there is no way of smoothing out the digital irregularities in the MDAC case. Only perhaps keeping the sample rate above audio (which they probably didn't do by then) or to use clever noise shaping techniques (which also seems unlikely).
> 
> /mr
> 
> Den s?n 4 aug. 2024 20:48Gordonjcp <gordonjcp at gjcp.net <mailto:gordonjcp at gjcp.net>> skrev:
> On Sun, Aug 04, 2024 at 06:26:06PM +0100, Tom Wiltshire wrote:
> > The Synclavier used DACs for VCAs like this too, fed with audio from other DACs. In that case it was a way of avoiding doing multiplies in hardware and not losing any resolution.
> > 
> 
> The Ensoniq DOC chip uses the same trick for the same reason.
> 
> -- 
> Gordonjcp
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
> View archive at: https://synth-diy.org/pipermail/synth-diy/ <https://synth-diy.org/pipermail/synth-diy/>
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy <https://synth-diy.org/mailman/listinfo/synth-diy>
> Selling or trading? Use marketplace at synth-diy.org <mailto:marketplace at synth-diy.org>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
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> Selling or trading? Use marketplace at synth-diy.org

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From electrocontinuo at gmail.com  Mon Aug  5 00:45:18 2024
From: electrocontinuo at gmail.com (Peter Pearson)
Date: Sun, 4 Aug 2024 18:45:18 -0400
Subject: [sdiy] Arp Quartet ADSR issues
In-Reply-To: <2097A61E-0C60-4919-A281-972D23CFAEA0@adambaby.com>
References: <275a2f12-b966-41e9-b3d8-88735efbd678@app.fastmail.com>
 <2097A61E-0C60-4919-A281-972D23CFAEA0@adambaby.com>
Message-ID: <CA+qbVc-9PpQvm1bUsTSRdWsdqhpgLOWFca+o4zofbUqOq=hyng@mail.gmail.com>

Those things sound great but they're made of plastic.  Not saying it's your
issue, but it's worth looking for physically damaged switches on the panel
board and bad solder joints on the connectors.

On Sun, Aug 4, 2024 at 6:09?PM Adam (synthDIY) <synthdiy at adambaby.com>
wrote:

>
>
> On 5 Aug 2024, at 4:58?AM, Ben Walker <ben at audio.computer> wrote:
>
>
> The KYBD GATE signal that is sent to the keyboard bus bar sits around +5V
> for the working sounds, and close to 0V for the others. So there?s no
> voltage hitting the input pin of the TDA1008, and therefore no output.
>
> Are you saying that the presence of the keyboard gate voltage is
> determined by which sound group you select from the front panel?
> That seems like an odd arrangement!
> That certainly needs more investigation!
> A
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
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From tom at electricdruid.net  Mon Aug  5 00:48:06 2024
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sun, 4 Aug 2024 23:48:06 +0100
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
 <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
Message-ID: <84C9D1AC-CED6-4DFF-8412-ACA4FA55253B@electricdruid.net>

Ah, here it is - the Synclavier way of doing it!

http://www.500sound.com/SyncII/synthschem.jpg



> On 4 Aug 2024, at 23:23, Mattias Rickardsson <mr at analogue.org> wrote:
> 
> Interesting thread.
> 
> Do these vintage examples use static amplification factors in their MDACs, or do they allow the digital value be modulated by envelopes and LFOs?
> 
> If they do modulate stuff, how is the result in terms of zipper noise etc? Unlike when using a VCA controlled by a CV generated from the very same DAC, there is no way of smoothing out the digital irregularities in the MDAC case. Only perhaps keeping the sample rate above audio (which they probably didn't do by then) or to use clever noise shaping techniques (which also seems unlikely).
> 
> /mr
> 
> Den s?n 4 aug. 2024 20:48Gordonjcp <gordonjcp at gjcp.net <mailto:gordonjcp at gjcp.net>> skrev:
> On Sun, Aug 04, 2024 at 06:26:06PM +0100, Tom Wiltshire wrote:
> > The Synclavier used DACs for VCAs like this too, fed with audio from other DACs. In that case it was a way of avoiding doing multiplies in hardware and not losing any resolution.
> > 
> 
> The Ensoniq DOC chip uses the same trick for the same reason.
> 
> -- 
> Gordonjcp
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
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From synth at schmitzbits.de  Mon Aug  5 01:44:16 2024
From: synth at schmitzbits.de (=?UTF-8?Q?Ren=C3=A9_Schmitz?=)
Date: Mon, 5 Aug 2024 01:44:16 +0200
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
 <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
Message-ID: <909f2e24-bb11-4b4d-80d0-4f5f7b8dd856@schmitzbits.de>

On 05.08.2024 00:23, Mattias Rickardsson wrote:
> Interesting thread.
>
> Do these vintage examples use static amplification factors in their 
> MDACs, or do they allow the digital value be modulated by envelopes 
> and LFOs?
>
> If they do modulate stuff, how is the result in terms of zipper noise 
> etc? Unlike when using a VCA controlled by a CV generated from the 
> very same DAC, there is no way of smoothing out the digital 
> irregularities in the MDAC case. Only perhaps keeping the sample rate 
> above audio (which they probably didn't do by then) or to use clever 
> noise shaping techniques (which also seems unlikely).
>
I did intend to use this in an instrument I built some time ago.

Yes, it does create noise from aliasing if you do not update the DAC 
fast enough. (You'd need a sampling rate well past audio and ideally low 
passes in the signal chain.)

In the end I switched over to a VCA and smoothing the CV instead.


Best,

 ?Ren?


> /mr
>
> Den s?n 4 aug. 2024 20:48Gordonjcp <gordonjcp at gjcp.net> skrev:
>
>     On Sun, Aug 04, 2024 at 06:26:06PM +0100, Tom Wiltshire wrote:
>     > The Synclavier used DACs for VCAs like this too, fed with audio
>     from other DACs. In that case it was a way of avoiding doing
>     multiplies in hardware and not losing any resolution.
>     >
>
>     The Ensoniq DOC chip uses the same trick for the same reason.
>
>     -- 
>     Gordonjcp
>
>     ________________________________________________________
>     This is the Synth-diy mailing list
>     Submit email to: Synth-diy at synth-diy.org
>     View archive at: https://synth-diy.org/pipermail/synth-diy/
>     Check your settings at:
>     https://synth-diy.org/mailman/listinfo/synth-diy
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>
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to:Synth-diy at synth-diy.org
> View archive at:https://synth-diy.org/pipermail/synth-diy/
> Check your settings at:https://synth-diy.org/mailman/listinfo/synth-diy
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-- 
--
synth at schmitzbits.de
http://schmitzbits.de
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From ben.pi.bradley at gmail.com  Mon Aug  5 02:50:25 2024
From: ben.pi.bradley at gmail.com (Ben Bradley)
Date: Sun, 4 Aug 2024 20:50:25 -0400
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <84C9D1AC-CED6-4DFF-8412-ACA4FA55253B@electricdruid.net>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
 <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
 <84C9D1AC-CED6-4DFF-8412-ACA4FA55253B@electricdruid.net>
Message-ID: <CA+wjhVuO+cmY8hLPfT_U9DLdHDUzo-qW3u__LRg7WfB6yGqjdw@mail.gmail.com>

My ISP (ATT) blocks that site saying it's a phishing site, but I got
an Archive copy here:

https://web.archive.org/web/20231116031028if_/http://www.500sound.com/SyncII/synthschem.jpg

On Sun, 4 Aug 2024 at 18:51, Tom Wiltshire <tom at electricdruid.net> wrote:
>
> Ah, here it is - the Synclavier way of doing it!
>
> http://www.500sound.com/SyncII/synthschem.jpg
>
>
>
> On 4 Aug 2024, at 23:23, Mattias Rickardsson <mr at analogue.org> wrote:
>
> Interesting thread.
>
> Do these vintage examples use static amplification factors in their MDACs, or do they allow the digital value be modulated by envelopes and LFOs?
>
> If they do modulate stuff, how is the result in terms of zipper noise etc? Unlike when using a VCA controlled by a CV generated from the very same DAC, there is no way of smoothing out the digital irregularities in the MDAC case. Only perhaps keeping the sample rate above audio (which they probably didn't do by then) or to use clever noise shaping techniques (which also seems unlikely).
>
> /mr
>
> Den s?n 4 aug. 2024 20:48Gordonjcp <gordonjcp at gjcp.net> skrev:
>>
>> On Sun, Aug 04, 2024 at 06:26:06PM +0100, Tom Wiltshire wrote:
>> > The Synclavier used DACs for VCAs like this too, fed with audio from other DACs. In that case it was a way of avoiding doing multiplies in hardware and not losing any resolution.
>> >
>>
>> The Ensoniq DOC chip uses the same trick for the same reason.
>>
>> --
>> Gordonjcp
>>
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
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> Selling or trading? Use marketplace at synth-diy.org


From ben at audio.computer  Mon Aug  5 10:45:57 2024
From: ben at audio.computer (Ben Walker)
Date: Mon, 05 Aug 2024 09:45:57 +0100
Subject: [sdiy] Arp Quartet ADSR issues
In-Reply-To: <CA+qbVc-9PpQvm1bUsTSRdWsdqhpgLOWFca+o4zofbUqOq=hyng@mail.gmail.com>
References: <275a2f12-b966-41e9-b3d8-88735efbd678@app.fastmail.com>
 <2097A61E-0C60-4919-A281-972D23CFAEA0@adambaby.com>
 <CA+qbVc-9PpQvm1bUsTSRdWsdqhpgLOWFca+o4zofbUqOq=hyng@mail.gmail.com>
Message-ID: <e0964f75-f3c3-40ac-af48-06d73abe3416@app.fastmail.com>

> Are you saying that the presence of the keyboard gate voltage is determined by which sound group you select from the front panel?
Yep! And on some sounds the keyboard gate is fed a square wave. That seems intentional, but the low voltage on some sounds less so.

> it's worth looking for physically damaged switches on the panel board and bad solder joints on the connectors.
Good point. And this one is definitely not a museum piece ? total rustbucket (and previously modified). The front panel sliders and switches were all crumbling ? I?ve replaced most of them but should double check the others, and the general health of solder/connectors around the envelope circuits.

On Sun, 4 Aug 2024, at 11:45 PM, Peter Pearson wrote:
> Those things sound great but they're made of plastic.  Not saying it's your issue, but it's worth looking for physically damaged switches on the panel board and bad solder joints on the connectors.
> 
> On Sun, Aug 4, 2024 at 6:09?PM Adam (synthDIY) <synthdiy at adambaby.com> wrote:
>> 
>> 
>>> On 5 Aug 2024, at 4:58?AM, Ben Walker <ben at audio.computer> wrote:
>>> 
>>> 
>>> The KYBD GATE signal that is sent to the keyboard bus bar sits around +5V for the working sounds, and close to 0V for the others. So there?s no voltage hitting the input pin of the TDA1008, and therefore no output.
>>> 
>> Are you saying that the presence of the keyboard gate voltage is determined by which sound group you select from the front panel?
>> That seems like an odd arrangement!
>> That certainly needs more investigation!
>> A
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
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From modular at go2.pl  Mon Aug  5 11:22:44 2024
From: modular at go2.pl (Roman Sowa)
Date: Mon, 5 Aug 2024 11:22:44 +0200
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
 <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
Message-ID: <5a1d7866-4b09-4f50-a632-e86a124cb659@go2.pl>

If the DAC is 8 bits or less, and passing sine or very low pass filtered 
waveform, the zipper noise will be clearly audible, but with increasing 
resolution and update rate of about 1ksps it should disappear into 
audiophiles-only-can-hear-it region.

Here's and idea, possibly too complex to consider it instead of regular 
VCA, but if you need precise amplitude control, it may be handy. Add a 
comparator working as zero-crossing detector, that when triggered, 
drives the LDAC input of the DAC, literally updating the DAC only at 
szero crossing of the signal, which is in no way to be audible. And even 
with fast envelopes, where each cycle changes in relatively big steps, 
this will be harmonically blended with the synth voice.
Obviously the DAC must have separate input for loading DAC register and 
I can't tell from memory if this is very popular thing in cheap DACs

Roman

W dniu 2024-08-05 o?00:23, Mattias Rickardsson pisze:
> Interesting thread.
> 
> Do these vintage examples use static amplification factors in their 
> MDACs, or do they allow the digital value be modulated by envelopes and 
> LFOs?
> 
> If they do modulate stuff, how is the result in terms of zipper noise 
> etc? Unlike when using a VCA controlled by a CV generated from the very 
> same DAC, there is no way of smoothing out the digital irregularities in 
> the MDAC case. Only perhaps keeping the sample rate above audio (which 
> they probably didn't do by then) or to use clever noise shaping 
> techniques (which also seems unlikely).
> 
> /mr
> 
> Den s?n 4 aug. 2024 20:48Gordonjcp <gordonjcp at gjcp.net 
> <mailto:gordonjcp at gjcp.net>> skrev:
> 
>     On Sun, Aug 04, 2024 at 06:26:06PM +0100, Tom Wiltshire wrote:
>      > The Synclavier used DACs for VCAs like this too, fed with audio
>     from other DACs. In that case it was a way of avoiding doing
>     multiplies in hardware and not losing any resolution.
>      >
> 
>     The Ensoniq DOC chip uses the same trick for the same reason.
> 
>     -- 
>     Gordonjcp
> 
>     ________________________________________________________
>     This is the Synth-diy mailing list
>     Submit email to: Synth-diy at synth-diy.org
>     <mailto:Synth-diy at synth-diy.org>
>     View archive at: https://synth-diy.org/pipermail/synth-diy/
>     <https://synth-diy.org/pipermail/synth-diy/>
>     Check your settings at:
>     https://synth-diy.org/mailman/listinfo/synth-diy
>     <https://synth-diy.org/mailman/listinfo/synth-diy>
>     Selling or trading? Use marketplace at synth-diy.org
>     <mailto:marketplace at synth-diy.org>
> 
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
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> Selling or trading? Use marketplace at synth-diy.org

From synthdiy at adambaby.com  Mon Aug  5 12:37:56 2024
From: synthdiy at adambaby.com (Adam (synthDIY))
Date: Mon, 5 Aug 2024 20:37:56 +1000
Subject: [sdiy] Arp Quartet ADSR issues
In-Reply-To: <e0964f75-f3c3-40ac-af48-06d73abe3416@app.fastmail.com>
References: <275a2f12-b966-41e9-b3d8-88735efbd678@app.fastmail.com>
 <2097A61E-0C60-4919-A281-972D23CFAEA0@adambaby.com>
 <CA+qbVc-9PpQvm1bUsTSRdWsdqhpgLOWFca+o4zofbUqOq=hyng@mail.gmail.com>
 <e0964f75-f3c3-40ac-af48-06d73abe3416@app.fastmail.com>
Message-ID: <47EBF1B6-C9E2-43BF-BA0C-24BA0FCB6C5F@adambaby.com>



> On 5 Aug 2024, at 6:45?PM, Ben Walker <ben at audio.computer> wrote:
> 
>> Are you saying that the presence of the keyboard gate voltage is determined by which sound group you select from the front panel?
> Yep! And on some sounds the keyboard gate is fed a square wave. That seems intentional, but the low voltage on some sounds less so.

Ha!
The square wave kybrd gate thing reminds me of the "REPEAT" option in my old miniKorg 700 - designed to replicate the sound of mandolins,  etc!!! Cos that's what you wanted a monosynth to do back in 1974...
Some of the schematics remind me also of my SH2000 - e.g. the "staircase" wave forms associated with the ADSR.
Probably a similar vintage.
As Peter says, there could easily be a lot of bad joints in this thing.
My SH2000 gave me a lot of grief until I finally bit the bullet and laboriously re-flowed every joint on the main board... and then voila! 

?

https://mezzoauto.blogspot.com/2019/05/roland-sh-2000.html?
Roland SH-2000
mezzoauto.blogspot.com
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From jacobwatters at gmail.com  Mon Aug  5 16:38:43 2024
From: jacobwatters at gmail.com (Jacob Watters)
Date: Mon, 5 Aug 2024 10:38:43 -0400
Subject: [sdiy] Arp Quartet ADSR issues
In-Reply-To: <275a2f12-b966-41e9-b3d8-88735efbd678@app.fastmail.com>
References: <275a2f12-b966-41e9-b3d8-88735efbd678@app.fastmail.com>
Message-ID: <CAKcdib34ZRLcpMo8S54-sSsi-qJftiTsqSMHD9WzuMuUR9N1EA@mail.gmail.com>

I recently repaired one that had a note that was stuck on. It turned out to
be the leg of a resistor that broke off. Replacing that fixed the issue. It
was difficult to see that the leg was broken until I applied heat to the
solder joint and the leg moved around freely.

Maybe try closely inspecting, and maybe even reflowing the solder, for all
components in the suspect areas.

*Jacob Watters*
JacobWatters.com <http://jacobwatters.com/>


On Sun, Aug 4, 2024 at 3:01?PM Ben Walker <ben at audio.computer> wrote:

> I?m fixing up an Arp Quartet that I got from eBay in a pretty bad
> condition. I?ve replaced a bunch of chips that were fried, repaired a
> broken ground trace on the filter board, and now it?s making some good
> noises. But there?s still something not right, and I can?t get my head
> around how it?s supposed to work from the schematic
> <https://www.polynominal.com/siel-orchestra/ARP%20Quartet%20Service%20Manual.pdf>
> .
>
> - The brass sound works, but the attack is always short and the decay
> always (very) long
> - The piano sound works
> - The organ sound doesn?t work (no output)
> - The string sound only works when ?percussion? is engaged.
>
> There?s obviously something wrong with the ADSR circuit. There are a
> couple of parts of that circuit (Board B, pp. 3-4 of the schematic) that
> are switched in and out by a 4016 quad switch, which explains why some
> sounds work (brass, strings + percussion and piano all enable the same bit
> of circuitry).
>
> The KYBD GATE signal that is sent to the keyboard bus bar sits around +5V
> for the working sounds, and close to 0V for the others. So there?s no
> voltage hitting the input pin of the TDA1008, and therefore no output.
>
> The ADSR signal just sits at +6V no matter what the setting or whether a
> key is pressed, which might explain the lack of working attack/decay
>
> Does anyone have experience with the Quartet, or is anyone able to
> interpret the schematic and take a guess at which part is not doing its job?
>
> Thanks,
>
> Ben
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
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From igg.debus at gmail.com  Mon Aug  5 17:28:19 2024
From: igg.debus at gmail.com (Ingo Debus)
Date: Mon, 5 Aug 2024 17:28:19 +0200
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
Message-ID: <F70BDA86-C69D-45A9-A0EF-A236B7648703@gmail.com>



> Am 04.08.2024 um 19:13 schrieb Benjamin Tremblay via Synth-diy <synth-diy at synth-diy.org>:
> 
> I can imagine making a state variable filter using a dual DAC as the ?gain' stages.  

Looong time ago (past millennium) I built a state variable filter like this, using the DAC8408. The circuit is in the data sheet, see page 13:
https://www.analog.com/media/en/technical-documentation/data-sheets/DAC8408.pdf <https://www.analog.com/media/en/technical-documentation/data-sheets/DAC8408.pdf>

One caveat, if you build the integrators as shown in the circuit (R from DAC8408, discrete C): The absolute value of R is quite inaccurate, see ?Input resistance" on page 2: 6 to 14 kOhms! It was necessary to build a rig to measure the resistance of each DAC chip and calculate the proper C values.
If you use the internal ?feedback resistor?, the problem goes away, since the feedback resistor is well matched to the other resistors that form the DAC. But for a programmable integrator you need an additional Opamp then.

@Chris: that circuit works well with bipolar signals.

Ingo
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From rainer at buchty.net  Mon Aug  5 17:46:03 2024
From: rainer at buchty.net (Rainer Buchty)
Date: Mon, 5 Aug 2024 17:46:03 +0200 (CEST)
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <20240804184343.GA11048@gjcp.net>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
Message-ID: <9a3dd573-fa98-fc21-6e6b-cd4aa6c5c1f3@buchty.net>

On Sun, 4 Aug 2024, Gordonjcp wrote:

> The Ensoniq DOC chip uses the same trick for the same reason.

To my understanding, it even saves on the amount of DACs and instead 
S&Hs the volume voltage, then using that as the waveform reference 
value for the "main" conversion.

Can be seen on the first-generation Mirages featuring the Rev A DOC 
where the S&H stuff is spelled out externally.

With Rev D, almost everything vanished inside the chip w/ only some 
external feedback signals pointing to it (VVref=-5V, WVref, Vlfdbk, Vol-).

Rainer

From mr at analogue.org  Mon Aug  5 20:38:54 2024
From: mr at analogue.org (Mattias Rickardsson)
Date: Mon, 5 Aug 2024 20:38:54 +0200
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <5a1d7866-4b09-4f50-a632-e86a124cb659@go2.pl>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
 <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
 <5a1d7866-4b09-4f50-a632-e86a124cb659@go2.pl>
Message-ID: <CAP92RBWhbWE+vuk9+F6OAsMg1BRB-nRJBPxf=Kk632QBf-kD2w@mail.gmail.com>

Is this MDAC "trick" more or less equivalent to using a "digital
potentiometer", or are those ICs significantly different?

/mr
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From mbryant at futurehorizons.com  Mon Aug  5 20:45:44 2024
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Mon, 5 Aug 2024 18:45:44 +0000
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <CAP92RBWhbWE+vuk9+F6OAsMg1BRB-nRJBPxf=Kk632QBf-kD2w@mail.gmail.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
 <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
 <5a1d7866-4b09-4f50-a632-e86a124cb659@go2.pl>
 <CAP92RBWhbWE+vuk9+F6OAsMg1BRB-nRJBPxf=Kk632QBf-kD2w@mail.gmail.com>
Message-ID: <CWLP265MB7132276B80A365FBC3B789F3DBBE2@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>


I think the digital pots are 256 resistors in a string with a MOSFET selecting each position, whereas the DAC use R-2R-4R-8R-16R-32R-128R feeding a summing amp.


________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Mattias Rickardsson <mr at analogue.org>
Sent: 05 August 2024 19:38
To: Roman Sowa <modular at go2.pl>
Cc: Synth DIY <synth-diy at synth-diy.org>
Subject: Re: [sdiy] using a dac as a digitally controlled amplifier

Is this MDAC "trick" more or less equivalent to using a "digital potentiometer", or are those ICs significantly different?

/mr

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From chris at chrismusic.de  Mon Aug  5 21:16:25 2024
From: chris at chrismusic.de (chris)
Date: Mon, 05 Aug 2024 21:16:25 +0200
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <CWLP265MB7132276B80A365FBC3B789F3DBBE2@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <CAP92RBWhbWE+vuk9+F6OAsMg1BRB-nRJBPxf=Kk632QBf-kD2w@mail.gmail.com>
 <CWLP265MB7132276B80A365FBC3B789F3DBBE2@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <20240805211232.17C1.CHRIS@chrismusic.de>

IIRC, the MCP4922 I used a lot (12 bits) is also just a large divider
chain and lots of switches.
4000 resistors isn't that much anymore...

Chris



On Mon, 5 Aug 2024 18:45:44 +0000 Mike Bryant
<mbryant at futurehorizons.com> wrote:

> 
> I think the digital pots are 256 resistors in a string with a MOSFET selecting each position, whereas the DAC use R-2R-4R-8R-16R-32R-128R feeding a summing amp.
> 
> 
> ________________________________
> From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Mattias Rickardsson <mr at analogue.org>
> Sent: 05 August 2024 19:38
> To: Roman Sowa <modular at go2.pl>
> Cc: Synth DIY <synth-diy at synth-diy.org>
> Subject: Re: [sdiy] using a dac as a digitally controlled amplifier
> 
> Is this MDAC "trick" more or less equivalent to using a "digital potentiometer", or are those ICs significantly different?
> 
> /mr


From brianw at audiobanshee.com  Mon Aug  5 21:42:05 2024
From: brianw at audiobanshee.com (brianw)
Date: Mon, 5 Aug 2024 12:42:05 -0700
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <9a3dd573-fa98-fc21-6e6b-cd4aa6c5c1f3@buchty.net>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
 <9a3dd573-fa98-fc21-6e6b-cd4aa6c5c1f3@buchty.net>
Message-ID: <76A453FD-7682-43C0-A1FB-BA02A4812624@audiobanshee.com>

On Aug 5, 2024, at 8:46 AM, Rainer Buchty <rainer at buchty.net> wrote:
> On Sun, 4 Aug 2024, Gordonjcp wrote:
>> The Ensoniq DOC chip uses the same trick for the same reason.
> 
> To my understanding, it even saves on the amount of DACs and instead S&Hs the volume voltage, then using that as the waveform reference value for the "main" conversion.
> 
> Can be seen on the first-generation Mirages featuring the Rev A DOC where the S&H stuff is spelled out externally.
> 
> With Rev D, almost everything vanished inside the chip w/ only some external feedback signals pointing to it (VVref=-5V, WVref, Vlfdbk, Vol-).
> 
> Rainer

Thank you. I was going to ask for more details.

Very interesting that the volume CV is isolated as an individual signal from a TDM output.

It is quite common to use several channels of S&H with a single DAC, at least when a DAC was expensive compared to an analog multiplexer, capacitors, and op-amp followers. Synths (like the Prophet-5 and many others) use many channels of S&H this way.

What is the DAC chip used with the DOC? Was it custom or off-the-shelf?

Brian



From brianw at audiobanshee.com  Mon Aug  5 21:48:56 2024
From: brianw at audiobanshee.com (brianw)
Date: Mon, 5 Aug 2024 12:48:56 -0700
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <CAP92RBWhbWE+vuk9+F6OAsMg1BRB-nRJBPxf=Kk632QBf-kD2w@mail.gmail.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
 <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
 <5a1d7866-4b09-4f50-a632-e86a124cb659@go2.pl>
 <CAP92RBWhbWE+vuk9+F6OAsMg1BRB-nRJBPxf=Kk632QBf-kD2w@mail.gmail.com>
Message-ID: <4E28AA94-7CC9-4707-A159-2C7B50ADE69B@audiobanshee.com>

I would expect that a DPOT would not allow its setting to be updated anywhere near audio sample rates.

A typical DAC is designed with the assumption and/or requirement that the Reference Voltage be constant. There is usually some sort of (external) filtering to remove as much noise above DC as possible. At the very least, there is usually no support for high bandwidth response between the VREF input and the main output.

An MDAC, in contrast, is designed with the assumption that the Reference Voltage will be changing. The bandwidth supported is something you would need to find in the corresponding data sheet.

In a way, a DPOT flips the two. The "Reference" Voltage input is expected to be an AC signal, and audio rates are very common. Meanwhile, the digital-controlled section probably only allows changes at rates well below audio frequencies. A number of DPOT designs actually have internal zero-crossing detection, such that every volume change is delayed until the next zero crossing. If you were attempting FM with such a chip, the results would be very distorted compared to expectations.

Brian


On Aug 5, 2024, at 11:38 AM, Mattias Rickardsson <mr at analogue.org> wrote:
> Is this MDAC "trick" more or less equivalent to using a "digital potentiometer", or are those ICs significantly different?
> 
> /mr



From brianw at audiobanshee.com  Mon Aug  5 21:54:28 2024
From: brianw at audiobanshee.com (brianw)
Date: Mon, 5 Aug 2024 12:54:28 -0700
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
Message-ID: <778509E4-3491-47F7-AA9A-ADA100EE7B46@audiobanshee.com>

This is a great question, and one that occurred to me as a question around 1984 when I built an 8-bit DAC and was working on digital synthesis. At the time, I had not discovered MDAC technology, and it was only years later that I found out that it's both possible and practical, having been used in commercial products.

Most DAC designs will not pass audio frequencies from the VREF input to the output, though.

Another question I had at the time was why a single transistor could not be used as a VCA. The eventual answer that I discovered is that the TR-808 does have single-transistor VCA stages, but they require AC filtering because a DC offset is inherent. As folks have pointed out in this thread, many MDAC designs would require similar DC manipulations.

Brian


On Aug 4, 2024, at 10:13 AM, Benjamin Tremblay wrote:
> Is there any practical application for synthesizers to pass an analog signal in as a reference voltage to a DAC?
> 12 bit DACs are pretty cheap these days, but VCAs aren?t expensive either. 
> Aside from cost, why would I want to use a DAC as a ?DCA?? 
> 
> I can imagine making a state variable filter using a dual DAC as the ?gain' stages.  
> It?s the kind of thing I would try just to see how well it worked? 
> 
> I suppose you inject one or more DACs into an oscillator to directly control pitch and waveform, some kind of DCO where stability and simplicity are cost-effective. 



From brianw at audiobanshee.com  Mon Aug  5 22:01:56 2024
From: brianw at audiobanshee.com (brianw)
Date: Mon, 5 Aug 2024 13:01:56 -0700
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <84C9D1AC-CED6-4DFF-8412-ACA4FA55253B@electricdruid.net>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
 <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
 <84C9D1AC-CED6-4DFF-8412-ACA4FA55253B@electricdruid.net>
Message-ID: <265CF45B-BD12-4616-901F-55DB7AB0EE06@audiobanshee.com>

On Aug 4, 2024, at 3:48 PM, Tom Wiltshire wrote:
> Ah, here it is - the Synclavier way of doing it!
> 
> http://www.500sound.com/SyncII/synthschem.jpg

A picture is worth a thousand words.

In that topology, it is easy to filter the Volume DAC output before it reaches the Envelope MDAC VREF input. Similarly, the Envelope MDAC output could be filtered before it reaches the Wave MDAC VREF input. This works because the waveform starts out digital, and it's amplitude CV coming in.

Unfortunately, if you feed the audio waveform in the VREF input, and use the digital sample value for the volume, then there'd be no way to smooth the volume changes with a simple analog filter.

Brian



From brianw at audiobanshee.com  Mon Aug  5 22:08:13 2024
From: brianw at audiobanshee.com (brianw)
Date: Mon, 5 Aug 2024 13:08:13 -0700
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <F70BDA86-C69D-45A9-A0EF-A236B7648703@gmail.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <F70BDA86-C69D-45A9-A0EF-A236B7648703@gmail.com>
Message-ID: <6683F135-0640-4E71-B845-D5AD0CD09D0E@audiobanshee.com>



On Aug 5, 2024, at 8:28 AM, Ingo Debus wrote:
> Am 04.08.2024 um 19:13 schrieb Benjamin Tremblay:
>> I can imagine making a state variable filter using a dual DAC as the ?gain' stages.  
> 
> Looong time ago (past millennium) I built a state variable filter like this, using the DAC8408. The circuit is in the data sheet, see page 13:
> https://www.analog.com/media/en/technical-documentation/data-sheets/DAC8408.pdf

There are many ways to design a DAC, and I am particularly fond of the way the DAC8408 does it. You get balanced outputs (complementary outputs), and the conversion can be very fast. I've used similar DAC designs capable of 125 MHz sample rates (yes, 125 MHz, not only 125 kHz).

The down side is that the output is current, not voltage, but sometimes that's a feature.

Brian


> One caveat, if you build the integrators as shown in the circuit (R from DAC8408, discrete C): The absolute value of R is quite inaccurate, see ?Input resistance" on page 2: 6 to 14 kOhms! It was necessary to build a rig to measure the resistance of each DAC chip and calculate the proper C values.
> If you use the internal ?feedback resistor?, the problem goes away, since the feedback resistor is well matched to the other resistors that form the DAC. But for a programmable integrator you need an additional Opamp then.
> 
> @Chris: that circuit works well with bipolar signals.
> 
> Ingo



From rainer at buchty.net  Mon Aug  5 23:04:14 2024
From: rainer at buchty.net (Rainer Buchty)
Date: Mon, 5 Aug 2024 23:04:14 +0200 (CEST)
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <76A453FD-7682-43C0-A1FB-BA02A4812624@audiobanshee.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
 <9a3dd573-fa98-fc21-6e6b-cd4aa6c5c1f3@buchty.net>
 <76A453FD-7682-43C0-A1FB-BA02A4812624@audiobanshee.com>
Message-ID: <fb7462e7-6918-b0f9-0b4f-fdf885fd072a@buchty.net>

On Mon, 5 Aug 2024, brianw wrote:

> What is the DAC chip used with the DOC? Was it custom or 
> off-the-shelf?

I have no information on that.

Considering that the DOC is based on ICS, Inc.'s mixed-signal ASIC 
technology, I would think that Ensoniq went with something from the ICS 
design library.

Unfortunately, the oldest ICS databooks I found are from 1994. So I'm 
not sure how closely they reflect the situation more than 10 years 
earlier when the DOC chip was designed and manufactured.

Rainer


From neil.johnson71 at gmail.com  Mon Aug  5 23:30:14 2024
From: neil.johnson71 at gmail.com (Neil Johnson)
Date: Mon, 5 Aug 2024 22:30:14 +0100
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
Message-ID: <CACZGMxKczgwQBHgs3esd7yFP2TqDtaE_XL4HacWb2ZZ0oxkSig@mail.gmail.com>

Hi Benjamin,

The Audio Precision System One does exactly this in its SVF-based sine
wave generator.  There are two MDAC hybrids that set the frequency of
the oscillator.  It allows easy control of the frequency from the
controller PC.

Cheers,
Neil

On Sun, 4 Aug 2024 at 18:17, Benjamin Tremblay via Synth-diy
<synth-diy at synth-diy.org> wrote:
>
> Is there any practical application for synthesizers to pass an analog signal in as a reference voltage to a DAC?
> 12 bit DACs are pretty cheap these days, but VCAs aren?t expensive either.
> Aside from cost, why would I want to use a DAC as a ?DCA??
>
> I can imagine making a state variable filter using a dual DAC as the ?gain' stages.
> It?s the kind of thing I would try just to see how well it worked?
>
> I suppose you inject one or more DACs into an oscillator to directly control pitch and waveform, some kind of DCO where stability and simplicity are cost-effective.
>
>
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org


From neil.johnson71 at gmail.com  Tue Aug  6 00:22:53 2024
From: neil.johnson71 at gmail.com (Neil Johnson)
Date: Mon, 5 Aug 2024 23:22:53 +0100
Subject: [sdiy] Synth meetups and must-see shops in Vienna?
In-Reply-To: <20240801205813.GA24169@gjcp.net>
References: <20240801205813.GA24169@gjcp.net>
Message-ID: <CACZGMxK5OM-DJhkqdAbKg=nT-wd_RoFY0dO_Rc2XAY6123GmkA@mail.gmail.com>

Speaking of synth meetups..

Timely reminder about this year's Cambridge Synth DIY weekend on
28th/29th September at Robinson College, Cambridge:

https://www.synth-diy.uk/

Cheers,
Neil

On Thu, 1 Aug 2024 at 22:00, Gordonjcp <gordonjcp at gjcp.net> wrote:
>
> Hi folks,
>
> As the subject says, does anyone know if there are any synth meetups in Vienna, or any particular shops, museums, or other interesting places I should visit while I'm here?
>
> I've already got Flash and Klangfarbe on my list :-)
>
> --
> Gordonjcp
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

From brianw at audiobanshee.com  Tue Aug  6 01:58:22 2024
From: brianw at audiobanshee.com (brianw)
Date: Mon, 5 Aug 2024 16:58:22 -0700
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <CACZGMxKczgwQBHgs3esd7yFP2TqDtaE_XL4HacWb2ZZ0oxkSig@mail.gmail.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <CACZGMxKczgwQBHgs3esd7yFP2TqDtaE_XL4HacWb2ZZ0oxkSig@mail.gmail.com>
Message-ID: <932522C0-52AC-4B03-87F1-5B1B2CDD029D@audiobanshee.com>

Thanks, Neil. That's very interesting.

I often use a software SVF with feedback gain of 1.0 to implement a sine wave generator, but had not thought of using an analog SVF for the same reason. How difficult is it to get the analog gain at exactly 1.0, so as to avoid distortion or decay? I expect that the two MDAC settings much be matched for good performance, or at least have enough resolution that they can easily be tweaked to match each other.

Brian


On Aug 5, 2024, at 2:30 PM, Neil Johnson wrote:
> Hi Benjamin,
> 
> The Audio Precision System One does exactly this in its SVF-based sine
> wave generator.  There are two MDAC hybrids that set the frequency of
> the oscillator.  It allows easy control of the frequency from the
> controller PC.
> 
> Cheers,
> Neil
> 
> On Sun, 4 Aug 2024 at 18:17, Benjamin Tremblay wrote:
>> 
>> Is there any practical application for synthesizers to pass an analog signal in as a reference voltage to a DAC?
>> 12 bit DACs are pretty cheap these days, but VCAs aren?t expensive either.
>> Aside from cost, why would I want to use a DAC as a ?DCA??
>> 
>> I can imagine making a state variable filter using a dual DAC as the ?gain' stages.
>> It?s the kind of thing I would try just to see how well it worked?
>> 
>> I suppose you inject one or more DACs into an oscillator to directly control pitch and waveform, some kind of DCO where stability and simplicity are cost-effective.



From brianw at audiobanshee.com  Tue Aug  6 02:03:49 2024
From: brianw at audiobanshee.com (brianw)
Date: Mon, 5 Aug 2024 17:03:49 -0700
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <932522C0-52AC-4B03-87F1-5B1B2CDD029D@audiobanshee.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <CACZGMxKczgwQBHgs3esd7yFP2TqDtaE_XL4HacWb2ZZ0oxkSig@mail.gmail.com>
 <932522C0-52AC-4B03-87F1-5B1B2CDD029D@audiobanshee.com>
Message-ID: <04E12400-ABF6-4745-8352-12B5595860AB@audiobanshee.com>

I guess that might be confusing the way I worded it. If I recall, in the software version the sum of the two feedback path gain values is 1.0, so neither gain alone is exactly 1.0 - I imagine that the analog version built around a pair of MDAC circuits would require the two gain settings to be carefully matched, according to the desired sine wave frequency.

Brian


On Aug 5, 2024, at 4:58 PM, brian wrote:
> Thanks, Neil. That's very interesting.
> 
> I often use a software SVF with feedback gain of 1.0 to implement a sine wave generator, but had not thought of using an analog SVF for the same reason. How difficult is it to get the analog gain at exactly 1.0, so as to avoid distortion or decay? I expect that the two MDAC settings much be matched for good performance, or at least have enough resolution that they can easily be tweaked to match each other.
> 
> Brian
> 
> 
> On Aug 5, 2024, at 2:30 PM, Neil Johnson wrote:
>> Hi Benjamin,
>> 
>> The Audio Precision System One does exactly this in its SVF-based sine
>> wave generator.  There are two MDAC hybrids that set the frequency of
>> the oscillator.  It allows easy control of the frequency from the
>> controller PC.
>> 
>> Cheers,
>> Neil
>> 
>> On Sun, 4 Aug 2024 at 18:17, Benjamin Tremblay wrote:
>>> 
>>> I can imagine making a state variable filter using a dual DAC as the ?gain' stages.
>>> It?s the kind of thing I would try just to see how well it worked?
>>> 
>>> I suppose you inject one or more DACs into an oscillator to directly control pitch and waveform, some kind of DCO where stability and simplicity are cost-effective.



From neil.johnson71 at gmail.com  Tue Aug  6 10:05:50 2024
From: neil.johnson71 at gmail.com (Neil Johnson)
Date: Tue, 6 Aug 2024 09:05:50 +0100
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <04E12400-ABF6-4745-8352-12B5595860AB@audiobanshee.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <CACZGMxKczgwQBHgs3esd7yFP2TqDtaE_XL4HacWb2ZZ0oxkSig@mail.gmail.com>
 <932522C0-52AC-4B03-87F1-5B1B2CDD029D@audiobanshee.com>
 <04E12400-ABF6-4745-8352-12B5595860AB@audiobanshee.com>
Message-ID: <CACZGMxJ2F4SmiFVToHSRQLiFGjSnE6uyU6tpOit7Zac1bK7Fzg@mail.gmail.com>

Hi Brian,

Detach your software brain!

You wrap an AGC loop around the oscillator to adjust the gain to meet
the amplitude requirement. Components are imperfect and drift with
everything so you need to actively manage the gain, you cannot just
rely on an exact number. Possibly the most well-known example of this
being HP's lamp AGC in the Wien oscillator.

Neil

On Tue, 6 Aug 2024 at 01:10, brianw <brianw at audiobanshee.com> wrote:
>
> I guess that might be confusing the way I worded it. If I recall, in the software version the sum of the two feedback path gain values is 1.0, so neither gain alone is exactly 1.0 - I imagine that the analog version built around a pair of MDAC circuits would require the two gain settings to be carefully matched, according to the desired sine wave frequency.
>
> Brian
>
>
> On Aug 5, 2024, at 4:58 PM, brian wrote:
> > Thanks, Neil. That's very interesting.
> >
> > I often use a software SVF with feedback gain of 1.0 to implement a sine wave generator, but had not thought of using an analog SVF for the same reason. How difficult is it to get the analog gain at exactly 1.0, so as to avoid distortion or decay? I expect that the two MDAC settings much be matched for good performance, or at least have enough resolution that they can easily be tweaked to match each other.
> >
> > Brian
> >
> >
> > On Aug 5, 2024, at 2:30 PM, Neil Johnson wrote:
> >> Hi Benjamin,
> >>
> >> The Audio Precision System One does exactly this in its SVF-based sine
> >> wave generator.  There are two MDAC hybrids that set the frequency of
> >> the oscillator.  It allows easy control of the frequency from the
> >> controller PC.
> >>
> >> Cheers,
> >> Neil
> >>
> >> On Sun, 4 Aug 2024 at 18:17, Benjamin Tremblay wrote:
> >>>
> >>> I can imagine making a state variable filter using a dual DAC as the ?gain' stages.
> >>> It?s the kind of thing I would try just to see how well it worked?
> >>>
> >>> I suppose you inject one or more DACs into an oscillator to directly control pitch and waveform, some kind of DCO where stability and simplicity are cost-effective.
>
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org


From modular at go2.pl  Tue Aug  6 11:05:25 2024
From: modular at go2.pl (Roman Sowa)
Date: Tue, 6 Aug 2024 11:05:25 +0200
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <CAP92RBWhbWE+vuk9+F6OAsMg1BRB-nRJBPxf=Kk632QBf-kD2w@mail.gmail.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
 <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
 <5a1d7866-4b09-4f50-a632-e86a124cb659@go2.pl>
 <CAP92RBWhbWE+vuk9+F6OAsMg1BRB-nRJBPxf=Kk632QBf-kD2w@mail.gmail.com>
Message-ID: <fd9622c0-53b6-4a24-be14-da506b89d0cc@go2.pl>

Digital pot gives you access to all 3 leads of the "pot", while MDAC has 
one end of the taped to GND shared with the rest of DAC circuit, and 
also typicaly a R-2R ladder while digipot seems to be always a resistor 
string.
Digi-pot has also rather tight tolerances on absolute resistance value 
of individual step resistors in case you'd want to use it as rheostat. I 
mean "tight" in a sense that you can tell it's 100k pot and not 
somewhere between 50k and 200k. In MDAC it's "don't care how much as 
long as they are all the same, 14.3k sounds like a good value"
Other than that it seems to be basicaly the same thing.

Roman

W dniu 2024-08-05 o?20:38, Mattias Rickardsson pisze:
> Is this MDAC "trick" more or less equivalent to using a "digital 
> potentiometer", or are those ICs?significantly different?
> 
> /mr
> 

From modular at go2.pl  Tue Aug  6 11:15:08 2024
From: modular at go2.pl (Roman Sowa)
Date: Tue, 6 Aug 2024 11:15:08 +0200
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <CWLP265MB7132276B80A365FBC3B789F3DBBE2@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
 <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
 <5a1d7866-4b09-4f50-a632-e86a124cb659@go2.pl>
 <CAP92RBWhbWE+vuk9+F6OAsMg1BRB-nRJBPxf=Kk632QBf-kD2w@mail.gmail.com>
 <CWLP265MB7132276B80A365FBC3B789F3DBBE2@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <a99865b6-6080-42a6-9fd1-d5b52e817981@go2.pl>

I have never seen in my life a DAC with R-2R-4R-8R-16R-32R-128R 
topology. It would be very difficult to make resistors with 128 ratio in 
required tolerance. It's either R-2R ladder or resistor string. Making 
same value resistors is much easier. They make resistor string DACs even 
up to 16 bits, that's a lot of tiny resistors. Sometimes it's split 
topology with part of the bits done in R-2R and part of bits with small 
resistor string.
There used to be DACs with capacitors instead of resistors, possibly 
because it's easier to achieve good precision and repeatability in 
making small cap than a resistor inside IC. But I think they are now 
relict of the past.
BTW, I don't know what technology is used in those modern multi GHz DACs 
used so widely today. Switching resistors at that speed sounds like 
technology stolen from aliens.

Roman

W dniu 2024-08-05 o?20:45, Mike Bryant pisze:
> 
> I think the digital pots are 256 resistors in a string with a MOSFET 
> selecting each position, whereas the DAC use R-2R-4R-8R-16R-32R-128R 
> feeding a summing amp.
> 
> 
> ------------------------------------------------------------------------
> *From:*?Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Mattias 
> Rickardsson <mr at analogue.org>
> *Sent:*?05 August 2024 19:38
> *To:*?Roman Sowa <modular at go2.pl>
> *Cc:*?Synth DIY <synth-diy at synth-diy.org>
> *Subject:*?Re: [sdiy] using a dac as a digitally controlled amplifier
> Is this MDAC "trick" more or less equivalent to using a "digital 
> potentiometer", or are those ICs?significantly different?
> 
> /mr
> 

From mbryant at futurehorizons.com  Tue Aug  6 11:48:04 2024
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Tue, 6 Aug 2024 09:48:04 +0000
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <a99865b6-6080-42a6-9fd1-d5b52e817981@go2.pl>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
 <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
 <5a1d7866-4b09-4f50-a632-e86a124cb659@go2.pl>
 <CAP92RBWhbWE+vuk9+F6OAsMg1BRB-nRJBPxf=Kk632QBf-kD2w@mail.gmail.com>
 <CWLP265MB7132276B80A365FBC3B789F3DBBE2@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <a99865b6-6080-42a6-9fd1-d5b52e817981@go2.pl>
Message-ID: <CWLP265MB71329BCA65DEF15B9044C829DBBF2@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

The high speed DACs we used in the 70s were of R-2R-4R-8R-16R-32R-64R-128R topology.  TRW, Analog Devices and I think Burr-Brown all made them using ceramic packages and laser trimming.  There was even a 10 bit one from TRW but it was horrendously expensive.

But I agree nowadays R-2R ladders are far more common so I was showing my age :-)

________________________________
From: Roman Sowa <modular at go2.pl>
Sent: 06 August 2024 10:15
To: Mike Bryant <mbryant at futurehorizons.com>; Mattias Rickardsson <mr at analogue.org>
Cc: Synth DIY <synth-diy at synth-diy.org>
Subject: Re: [sdiy] using a dac as a digitally controlled amplifier

I have never seen in my life a DAC with R-2R-4R-8R-16R-32R-128R
topology. It would be very difficult to make resistors with 128 ratio in
required tolerance. It's either R-2R ladder or resistor string. Making
same value resistors is much easier. They make resistor string DACs even
up to 16 bits, that's a lot of tiny resistors. Sometimes it's split
topology with part of the bits done in R-2R and part of bits with small
resistor string.
There used to be DACs with capacitors instead of resistors, possibly
because it's easier to achieve good precision and repeatability in
making small cap than a resistor inside IC. But I think they are now
relict of the past.
BTW, I don't know what technology is used in those modern multi GHz DACs
used so widely today. Switching resistors at that speed sounds like
technology stolen from aliens.

Roman

W dniu 2024-08-05 o 20:45, Mike Bryant pisze:
>
> I think the digital pots are 256 resistors in a string with a MOSFET
> selecting each position, whereas the DAC use R-2R-4R-8R-16R-32R-128R
> feeding a summing amp.
>
>
> ------------------------------------------------------------------------
> *From:* Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Mattias
> Rickardsson <mr at analogue.org>
> *Sent:* 05 August 2024 19:38
> *To:* Roman Sowa <modular at go2.pl>
> *Cc:* Synth DIY <synth-diy at synth-diy.org>
> *Subject:* Re: [sdiy] using a dac as a digitally controlled amplifier
> Is this MDAC "trick" more or less equivalent to using a "digital
> potentiometer", or are those ICs significantly different?
>
> /mr
>
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From tom at electricdruid.net  Tue Aug  6 12:32:42 2024
From: tom at electricdruid.net (Tom Wiltshire)
Date: Tue, 6 Aug 2024 11:32:42 +0100
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
Message-ID: <794CB13E-0503-41C7-B104-9A6E1B0D2336@electricdruid.net>

Another example occurred to me, which is the Sequential Pro-FX programmable effects unit. It uses various techniques to control the circuits, but the 7524 8-bit MDAC is amongst them.

The MDAC is still available as the Analog Devices AD7524, Texas TLC7524, PMI PM7524, Micro Power Systems MP7524, and Maxim MX7524 if you want to try it!


> On 4 Aug 2024, at 18:13, Benjamin Tremblay via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> Is there any practical application for synthesizers to pass an analog signal in as a reference voltage to a DAC?
> 12 bit DACs are pretty cheap these days, but VCAs aren?t expensive either. 
> Aside from cost, why would I want to use a DAC as a ?DCA?? 
> 
> I can imagine making a state variable filter using a dual DAC as the ?gain' stages.  
> It?s the kind of thing I would try just to see how well it worked? 
> 
> I suppose you inject one or more DACs into an oscillator to directly control pitch and waveform, some kind of DCO where stability and simplicity are cost-effective. 
> 
> 
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org



From jschwich53 at comcast.net  Tue Aug  6 21:28:16 2024
From: jschwich53 at comcast.net (Jay Schwichtenberg)
Date: Tue, 6 Aug 2024 12:28:16 -0700
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
Message-ID: <2a967426-2571-4d42-aa2c-c57eb20e4824@comcast.net>

Another thing to think about with digital pots is they come in 2 types. 
Most are uni-polar (0V to V+), but there are some out there that are 
bi-polar on their inputs. So you have to pay attention to what the 
circuit is and pick the right one.

Jay S.


From brianw at audiobanshee.com  Wed Aug  7 01:04:41 2024
From: brianw at audiobanshee.com (brianw)
Date: Tue, 6 Aug 2024 16:04:41 -0700
Subject: [sdiy] using a dac as a digitally controlled amplifier
In-Reply-To: <a99865b6-6080-42a6-9fd1-d5b52e817981@go2.pl>
References: <0C4C2F80-6E29-4A08-AECF-B73FC252F221@me.com>
 <4749c9b1-927e-424b-b339-488fd4487117@go2.pl>
 <E66B7EA5-2837-47DD-9E2D-3975B46832B4@electricdruid.net>
 <20240804184343.GA11048@gjcp.net>
 <CAP92RBWsEWs90uOdnuB5pxDygYi6xNN2r5Q5KrgefhS+E5EPvw@mail.gmail.com>
 <5a1d7866-4b09-4f50-a632-e86a124cb659@go2.pl>
 <CAP92RBWhbWE+vuk9+F6OAsMg1BRB-nRJBPxf=Kk632QBf-kD2w@mail.gmail.com>
 <CWLP265MB7132276B80A365FBC3B789F3DBBE2@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <a99865b6-6080-42a6-9fd1-d5b52e817981@go2.pl>
Message-ID: <0BB4733B-EFD2-4856-92C7-9BB8866B28E1@audiobanshee.com>

On Aug 6, 2024, at 2:15 AM, Roman Sowa wrote:
> BTW, I don't know what technology is used in those modern multi GHz DACs used so widely today. Switching resistors at that speed sounds like technology stolen from aliens.

The fastest designs that I know of use current sources, and the switching is fast because the current is never turned off. It's merely redirected between the normal and inverted outputs. It's difficult to go beyond 14 bits, because there you have an MSB current source that is 16384 times the LSB current source ... very difficult to maintain precision across that range.

Which multi GHz DAC chip(s) are you looking at?

Brian



From kogz23 at yahoo.com  Wed Aug  7 03:59:32 2024
From: kogz23 at yahoo.com (al spitzley)
Date: Wed, 7 Aug 2024 01:59:32 +0000 (UTC)
Subject: [sdiy] Roland Jupiter 6 issues
References: <581936990.2448700.1722995972304.ref@mail.yahoo.com>
Message-ID: <581936990.2448700.1722995972304@mail.yahoo.com>


Hi all,I?m working on a Jupiter 6 with an issue that is confusing me and I?m wondering if anyone may have encountered a similar issue.Certain patches ?crash? the machine. The patch will load then after the keyboard is played it causes the issues.?Always the same patches. The tape enable button lights up and the machine freezes. In?manual mode I can?t crash it. I?ve tried reloading the patches and still a few patches then keyboard trigger?create a crash.I tried replacing the ram and no luck.Thanks in advance for any thoughts!Al

Sent from Yahoo Mail for iPhone
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From synthdiy at adambaby.com  Wed Aug  7 05:12:15 2024
From: synthdiy at adambaby.com (Adam (synthDIY))
Date: Wed, 7 Aug 2024 13:12:15 +1000
Subject: [sdiy] Roland Jupiter 6 issues
In-Reply-To: <581936990.2448700.1722995972304@mail.yahoo.com>
References: <581936990.2448700.1722995972304.ref@mail.yahoo.com>
 <581936990.2448700.1722995972304@mail.yahoo.com>
Message-ID: <A32409EB-224C-41A2-B584-908F26FCA40A@adambaby.com>

When it "freezes" with the TAPE button lit, are you able to perform save or load functions? In other words,  is the machine erroneously going into TAPE mode by itself?
I saw this in the SM

?


Another thought:
Have you tried loading another source of patches?

OR,
 with the problem patches, can you try to re-save them to the same patch number (before you play a key - it's the key press that triggers the crash, right?)
in case the cassette data is corrupt? Just thinking out loud here...

A











> On 7 Aug 2024, at 11:59?AM, al spitzley via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> 
> Hi all,
> I?m working on a Jupiter 6 with an issue that is confusing me and I?m wondering if anyone may have encountered a similar issue.
> Certain patches ?crash? the machine. The patch will load then after the keyboard is played it causes the issues. Always the same patches. The tape enable button lights up and the machine freezes. In manual mode I can?t crash it. I?ve tried reloading the patches and still a few patches then keyboard trigger create a crash.I tried replacing the ram and no luck.
> Thanks in advance for any thoughts!
> Al
> 
> Sent from Yahoo Mail for iPhone <https://mail.onelink.me/107872968?pid=nativeplacement&c=Global_Acquisition_YMktg_315_Internal_EmailSignature&af_sub1=Acquisition&af_sub2=Global_YMktg&af_sub3=&af_sub4=100000604&af_sub5=EmailSignature__Static_>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

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From kogz23 at yahoo.com  Wed Aug  7 05:57:22 2024
From: kogz23 at yahoo.com (al spitzley)
Date: Wed, 7 Aug 2024 03:57:22 +0000 (UTC)
Subject: [sdiy] Roland Jupiter 6 issues
In-Reply-To: <A32409EB-224C-41A2-B584-908F26FCA40A@adambaby.com>
References: <581936990.2448700.1722995972304.ref@mail.yahoo.com>
 <581936990.2448700.1722995972304@mail.yahoo.com>
 <A32409EB-224C-41A2-B584-908F26FCA40A@adambaby.com>
Message-ID: <835878280.2477700.1723003042377@mail.yahoo.com>

Good thoughts, thank you! I will check this tomorrow. I saw that thing in the service manual but the revision I have is a later model so I assumed it wasn?t relevant to my issue.Cheers?Al


Sent from Yahoo Mail for iPhone


On Tuesday, August 6, 2024, 8:12 PM, Adam (synthDIY) <synthdiy at adambaby.com> wrote:

When it "freezes" with the TAPE button lit, are you able to perform save or load functions? In other words, ?is the machine erroneously going into TAPE mode by itself?I saw this in the SM


Another thought:Have you tried loading another source of patches?
OR,?with the problem patches, can you try to re-save them to the same patch number (before you play a key - it's the key press that triggers the crash, right?)in case the cassette data is corrupt? Just thinking out loud here...
A











On 7 Aug 2024, at 11:59?AM, al spitzley via Synth-diy <synth-diy at synth-diy.org> wrote:

Hi all,I?m working on a Jupiter 6 with an issue that is confusing me and I?m wondering if anyone may have encountered a similar issue.Certain patches ?crash? the machine. The patch will load then after the keyboard is played it causes the issues.?Always the same patches. The tape enable button lights up and the machine freezes. In?manual mode I can?t crash it. I?ve tried reloading the patches and still a few patches then keyboard trigger?create a crash.I tried replacing the ram and no luck.Thanks in advance for any thoughts!Al

Sent from Yahoo Mail for iPhone
________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
Selling or trading? Use marketplace at synth-diy.org





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From oakleysound at gmail.com  Wed Aug  7 09:28:01 2024
From: oakleysound at gmail.com (Tony Allgood)
Date: Wed, 7 Aug 2024 08:28:01 +0100
Subject: [sdiy] Roland Jupiter 6 issues
In-Reply-To: <581936990.2448700.1722995972304@mail.yahoo.com>
References: <581936990.2448700.1722995972304.ref@mail.yahoo.com>
 <581936990.2448700.1722995972304@mail.yahoo.com>
Message-ID: <3521001d-73c8-4a43-8f56-681f4c5ea034@gmail.com>

I have seen similar behaviour before with various JP-6 units over the 
years. What has always fixed it is going into manual mode. Create a 
simple standard 'init' patch, something like a classic analogue pluck 
sound will do. But it doesn't matter - just something you know the sound of.

Then program that same patch into *every* memory location.

Now check every patch still sounds the same and no crashes occur.

Reload the factory patches via tape if you wish.

However, if it is your own patches you are trying to load, then it could 
be that it is those that are corrupted. In this case, it is probably 
better to reprogram those sounds in manual mode.

Tony

www.oakleysound.com

From nathan at idmclassics.net  Wed Aug  7 20:42:05 2024
From: nathan at idmclassics.net (Nathan Trites)
Date: Wed, 7 Aug 2024 14:42:05 -0400
Subject: [sdiy] Roland Jupiter 6 issues
In-Reply-To: <3521001d-73c8-4a43-8f56-681f4c5ea034@gmail.com>
References: <581936990.2448700.1722995972304.ref@mail.yahoo.com>
 <581936990.2448700.1722995972304@mail.yahoo.com>
 <3521001d-73c8-4a43-8f56-681f4c5ea034@gmail.com>
Message-ID: <CAHy3N6B-Nj=cs_RZa1hvSrsNOPMKuyYdj0ZGy_eCZxNJqNfYkw@mail.gmail.com>

On one Jupiter 6 I did, I was convinced the RAM was bad because no matter
what there would always be a few corrupt patches that would lock up the
synth. Eventually I figured out the patches that failed had to do with the
level I was doing the playback at, and it was consistent across every
interface I have - the only solution was giving the tape signal an absurd
amount of gain thru a preamp. If I recall the dump I got online was already
normalized, and the cassette interface on the synth had no issues, so
unless the CPU had a problem, it was possibly due to the frequency response
of the specific dump or something like that. Ever since then I've done
cassette restores on Jupiter 6's by giving it a ton of gain thru a mixer
channel, and haven't had any patch dump issues yet. All that to say - don't
rule out cranking the gain like crazy.

I've also had to do what Tony describes to get JP-6 memory to work
correctly

Nathan

On Wed, Aug 7, 2024 at 3:28?AM Tony Allgood via Synth-diy <
synth-diy at synth-diy.org> wrote:

> I have seen similar behaviour before with various JP-6 units over the
> years. What has always fixed it is going into manual mode. Create a
> simple standard 'init' patch, something like a classic analogue pluck
> sound will do. But it doesn't matter - just something you know the sound
> of.
>
> Then program that same patch into *every* memory location.
>
> Now check every patch still sounds the same and no crashes occur.
>
> Reload the factory patches via tape if you wish.
>
> However, if it is your own patches you are trying to load, then it could
> be that it is those that are corrupted. In this case, it is probably
> better to reprogram those sounds in manual mode.
>
> Tony
>
> www.oakleysound.com
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
>
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From kogz23 at yahoo.com  Wed Aug  7 23:08:52 2024
From: kogz23 at yahoo.com (al spitzley)
Date: Wed, 7 Aug 2024 21:08:52 +0000 (UTC)
Subject: [sdiy] Roland Jupiter 6 issues
In-Reply-To: <CAHy3N6B-Nj=cs_RZa1hvSrsNOPMKuyYdj0ZGy_eCZxNJqNfYkw@mail.gmail.com>
References: <581936990.2448700.1722995972304.ref@mail.yahoo.com>
 <581936990.2448700.1722995972304@mail.yahoo.com>
 <3521001d-73c8-4a43-8f56-681f4c5ea034@gmail.com>
 <CAHy3N6B-Nj=cs_RZa1hvSrsNOPMKuyYdj0ZGy_eCZxNJqNfYkw@mail.gmail.com>
Message-ID: <676353605.2660928.1723064932689@mail.yahoo.com>

Thanks for the ideas.I tried cranking the gain and no luck. Different results each time. Aargh!When it ?freezes? with the Tape button lit it will not go into load. The only way to get out of it is to hit the Tape button. Occasionally it completely locks up and I have to restart.I?m having issues saving to the factory patch area. If I create a patch on A1, save it, create a different one on A2 (for example) it will save but also save into A1 or any previous patches I?ve just created. So I can?t create different patches when the Patch button is lit. I?m thinking this could be user error and confusion over factory patches vs user patches.I?m going to try loading factory patches using a utility?eprom I found on the internet. I?ll be away for a few days and will report back.Thanks again?Al


Sent from Yahoo Mail for iPhone


On Wednesday, August 7, 2024, 11:55 AM, Nathan Trites <nathan at idmclassics.net> wrote:

On one Jupiter 6 I did, I was convinced the RAM was bad because no matter what there would always be a few corrupt patches that would lock up the synth. Eventually I figured out the patches that failed had to do with the level I was doing the playback at, and it was consistent across every interface I have - the only solution was giving the tape signal an absurd amount of gain thru a preamp. If I recall the dump I got online was already normalized, and the cassette interface on the synth had no issues, so unless the CPU had a problem, it was possibly due to the frequency response of the specific dump or something like that. Ever since then I've done cassette restores on Jupiter 6's by giving it a ton of gain thru a mixer channel, and haven't had any patch dump issues yet. All that to say - don't rule out cranking the gain like crazy.?
I've also had to do what Tony describes to get JP-6 memory to work correctly?

Nathan
On Wed, Aug 7, 2024 at 3:28?AM Tony Allgood via Synth-diy <synth-diy at synth-diy.org> wrote:

I have seen similar behaviour before with various JP-6 units over the 
years. What has always fixed it is going into manual mode. Create a 
simple standard 'init' patch, something like a classic analogue pluck 
sound will do. But it doesn't matter - just something you know the sound of.

Then program that same patch into *every* memory location.

Now check every patch still sounds the same and no crashes occur.

Reload the factory patches via tape if you wish.

However, if it is your own patches you are trying to load, then it could 
be that it is those that are corrupted. In this case, it is probably 
better to reprogram those sounds in manual mode.

Tony

www.oakleysound.com
________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
Selling or trading? Use marketplace at synth-diy.org


________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
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Selling or trading? Use marketplace at synth-diy.org



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From mr at analogue.org  Wed Aug  7 23:19:24 2024
From: mr at analogue.org (Mattias Rickardsson)
Date: Wed, 7 Aug 2024 23:19:24 +0200
Subject: [sdiy] Sampler with tape dump?
Message-ID: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>

Hi,
After some cassette backup discussions, a silly idea came up.

Old synths often had tape dump as a means of backing up sounds.
Nowadays it's easier to use a sampler or computer than a cassette
tape, since it's just audio.
Sooo... turning this on its head:

Were there ever any old sampler that would let you store sample data as a
tape dump? (-:

/mr
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From synthdiy at adambaby.com  Wed Aug  7 23:33:51 2024
From: synthdiy at adambaby.com (Adam (synthDIY))
Date: Thu, 8 Aug 2024 07:33:51 +1000
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
Message-ID: <C5F95F02-A804-4ED8-84D8-013BFED2A480@adambaby.com>

Akai S-612 ?

> On 8 Aug 2024, at 7:19?AM, Mattias Rickardsson <mr at analogue.org> wrote:
> 
> Hi,
> After some cassette backup discussions, a silly idea came up.
> 
> Old synths often had tape dump as a means of backing up sounds.
> Nowadays it's easier to use a sampler or computer than a cassette tape, since it's just audio.
> Sooo... turning this on its head:
> 
> Were there ever any old sampler that would let you store sample data as a tape dump? (-:
> 
> /mr
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org



From brianw at audiobanshee.com  Wed Aug  7 23:41:38 2024
From: brianw at audiobanshee.com (brianw)
Date: Wed, 7 Aug 2024 14:41:38 -0700
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
Message-ID: <CC0E98AC-A0BA-4162-982E-F782CC9A3508@audiobanshee.com>

I seriously doubt it. The dump to tape would take so long that it would probably have a 100% chance of error. The size of a synth patch versus the size of a sample is quite a significant difference.

There are samplers with MIDI System Exclusive messages for dumping samples, and there's a Sample Dump Standard that came after many samplers has rolled their own protocols. You probably already know this. Even MIDI is a slow communications protocol for sample data transfer, and I can't imagine how slow it would be for tape.

I was going to guess that the first commercial sampler came after MIDI was invented, but the internet tells me that Harry Mendell's Computer Music Melodian came out in 1976. There's no mention of how that might have dumped samples, but it was built on a PDP-8 computer, so I suppose there was backup to that kind of rack mounted computer tape drive (certainly not a hand-held cassette).

One article says that "old" samplers used SCSI, but I think that SCSI was too expensive for many samplers, so they used floppy storage mainly. SCSI was first available in 1981, so any samplers older than that would not have used SCSI.

Brian


On Aug 7, 2024, at 2:19 PM, Mattias Rickardsson <mr at analogue.org> wrote:
> Hi,
> After some cassette backup discussions, a silly idea came up.
> 
> Old synths often had tape dump as a means of backing up sounds.
> Nowadays it's easier to use a sampler or computer than a cassette tape, since it's just audio.
> Sooo... turning this on its head:
> 
> Were there ever any old sampler that would let you store sample data as a tape dump? (-:
> 
> /mr



From synthdiy at adambaby.com  Wed Aug  7 23:41:35 2024
From: synthdiy at adambaby.com (Adam (synthDIY))
Date: Thu, 8 Aug 2024 07:41:35 +1000
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
Message-ID: <25B13EF2-344E-470B-802C-E47CC1FE81BA@adambaby.com>

My S612 came with a QuikDisk drive (what a monster!) but there was also provision for a "Commodore" cassette interface, not provided as standard on most machines (the port is empty on mine).

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> On 8 Aug 2024, at 7:19?AM, Mattias Rickardsson <mr at analogue.org> wrote:
> 
> Hi,
> After some cassette backup discussions, a silly idea came up.
> 
> Old synths often had tape dump as a means of backing up sounds.
> Nowadays it's easier to use a sampler or computer than a cassette tape, since it's just audio.
> Sooo... turning this on its head:
> 
> Were there ever any old sampler that would let you store sample data as a tape dump? (-:
> 
> /mr
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org


From spridley1 at gmail.com  Thu Aug  8 00:28:18 2024
From: spridley1 at gmail.com (S Ridley)
Date: Wed, 7 Aug 2024 23:28:18 +0100
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
Message-ID: <CAPgGCkKLMxctd=73pJU0zo6KPZo8gFgahtOmbMqP+WLkvbvz0g@mail.gmail.com>

Cheetah MD8 drum machine dumped and (occasionally) loaded samples to/from
cassette.
Kits and samples were only available on cassette AFAIK, although if you
ever got them to load, you could save them via sysex.

Steve

On Wed, 7 Aug 2024 at 22:23, Mattias Rickardsson <mr at analogue.org> wrote:

> Hi,
> After some cassette backup discussions, a silly idea came up.
>
> Old synths often had tape dump as a means of backing up sounds.
> Nowadays it's easier to use a sampler or computer than a cassette
> tape, since it's just audio.
> Sooo... turning this on its head:
>
> Were there ever any old sampler that would let you store sample data as a
> tape dump? (-:
>
> /mr
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From gordonjcp at gjcp.net  Thu Aug  8 01:19:26 2024
From: gordonjcp at gjcp.net (Gordonjcp)
Date: Thu, 8 Aug 2024 00:19:26 +0100
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CC0E98AC-A0BA-4162-982E-F782CC9A3508@audiobanshee.com>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
 <CC0E98AC-A0BA-4162-982E-F782CC9A3508@audiobanshee.com>
Message-ID: <20240807231926.GA26472@gjcp.net>

On Wed, Aug 07, 2024 at 02:41:38PM -0700, brianw wrote:
> I seriously doubt it. The dump to tape would take so long that it would probably have a 100% chance of error. The size of a synth patch versus the size of a sample is quite a significant difference.

It depends. Home computers with as much as 128kB of RAM used tape for storage, so you could easily store an entire Ensoniq Mirage's worth of sample and program RAM to tape. Using standard ZX tape routines it'd take about 15 minutes to load or save, considerably slower than floppy disk. Even using something like Speedlock would only take that down to about 10-11 minutes.

-- 
Gordonjcp


From kogz23 at yahoo.com  Thu Aug  8 04:24:49 2024
From: kogz23 at yahoo.com (al spitzley)
Date: Thu, 8 Aug 2024 02:24:49 +0000 (UTC)
Subject: [sdiy] Roland Jupiter 6 issues
In-Reply-To: <676353605.2660928.1723064932689@mail.yahoo.com>
References: <581936990.2448700.1722995972304.ref@mail.yahoo.com>
 <581936990.2448700.1722995972304@mail.yahoo.com>
 <3521001d-73c8-4a43-8f56-681f4c5ea034@gmail.com>
 <CAHy3N6B-Nj=cs_RZa1hvSrsNOPMKuyYdj0ZGy_eCZxNJqNfYkw@mail.gmail.com>
 <676353605.2660928.1723064932689@mail.yahoo.com>
Message-ID: <215800599.2717459.1723083889354@mail.yahoo.com>

A quick question for Tony. When you say to program all the patches with an Init patch are you referring to?that the Factory patches with the Patch led lit?Cheers?Al


Sent from Yahoo Mail for iPhone


On Wednesday, August 7, 2024, 2:08 PM, al spitzley <kogz23 at yahoo.com> wrote:

Thanks for the ideas.I tried cranking the gain and no luck. Different results each time. Aargh!When it ?freezes? with the Tape button lit it will not go into load. The only way to get out of it is to hit the Tape button. Occasionally it completely locks up and I have to restart.I?m having issues saving to the factory patch area. If I create a patch on A1, save it, create a different one on A2 (for example) it will save but also save into A1 or any previous patches I?ve just created. So I can?t create different patches when the Patch button is lit. I?m thinking this could be user error and confusion over factory patches vs user patches.I?m going to try loading factory patches using a utility?eprom I found on the internet. I?ll be away for a few days and will report back.Thanks again?Al


Sent from Yahoo Mail for iPhone


On Wednesday, August 7, 2024, 11:55 AM, Nathan Trites <nathan at idmclassics.net> wrote:

On one Jupiter 6 I did, I was convinced the RAM was bad because no matter what there would always be a few corrupt patches that would lock up the synth. Eventually I figured out the patches that failed had to do with the level I was doing the playback at, and it was consistent across every interface I have - the only solution was giving the tape signal an absurd amount of gain thru a preamp. If I recall the dump I got online was already normalized, and the cassette interface on the synth had no issues, so unless the CPU had a problem, it was possibly due to the frequency response of the specific dump or something like that. Ever since then I've done cassette restores on Jupiter 6's by giving it a ton of gain thru a mixer channel, and haven't had any patch dump issues yet. All that to say - don't rule out cranking the gain like crazy.?
I've also had to do what Tony describes to get JP-6 memory to work correctly?

Nathan
On Wed, Aug 7, 2024 at 3:28?AM Tony Allgood via Synth-diy <synth-diy at synth-diy.org> wrote:

I have seen similar behaviour before with various JP-6 units over the 
years. What has always fixed it is going into manual mode. Create a 
simple standard 'init' patch, something like a classic analogue pluck 
sound will do. But it doesn't matter - just something you know the sound of.

Then program that same patch into *every* memory location.

Now check every patch still sounds the same and no crashes occur.

Reload the factory patches via tape if you wish.

However, if it is your own patches you are trying to load, then it could 
be that it is those that are corrupted. In this case, it is probably 
better to reprogram those sounds in manual mode.

Tony

www.oakleysound.com
________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
Selling or trading? Use marketplace at synth-diy.org


________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
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Selling or trading? Use marketplace at synth-diy.org






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From synthdiy at adambaby.com  Thu Aug  8 05:13:43 2024
From: synthdiy at adambaby.com (Adam (synthDIY))
Date: Thu, 8 Aug 2024 13:13:43 +1000
Subject: [sdiy] Roland Jupiter 6 issues
In-Reply-To: <215800599.2717459.1723083889354@mail.yahoo.com>
References: <581936990.2448700.1722995972304.ref@mail.yahoo.com>
 <581936990.2448700.1722995972304@mail.yahoo.com>
 <3521001d-73c8-4a43-8f56-681f4c5ea034@gmail.com>
 <CAHy3N6B-Nj=cs_RZa1hvSrsNOPMKuyYdj0ZGy_eCZxNJqNfYkw@mail.gmail.com>
 <676353605.2660928.1723064932689@mail.yahoo.com>
 <215800599.2717459.1723083889354@mail.yahoo.com>
Message-ID: <4E04F604-2BE1-4AF5-815D-166C1A3D4C90@adambaby.com>

When you say "Patch led" are you referring to the Patch Preset LED?
I don't own a JP6 but on the JP8 Roland employ a potentially confusing terminology, and I think they persisted with the JP6:
A "patch" is a single memory slot containing the synth voice parameters for VCO VCF VCA etc.
A "Patch Preset" is a special memory that holds two such patches along with their voice assignments/splits/glide etc

A

> On 8 Aug 2024, at 12:24?PM, al spitzley via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> A quick question for Tony. When you say to program all the patches with an Init patch are you referring to that the Factory patches with the Patch led lit?
> Cheers 
> Al
> 
> 
> Sent from Yahoo Mail for iPhone <https://mail.onelink.me/107872968?pid=nativeplacement&c=Global_Acquisition_YMktg_315_Internal_EmailSignature&af_sub1=Acquisition&af_sub2=Global_YMktg&af_sub3=&af_sub4=100000604&af_sub5=EmailSignature__Static_>
> 
> On Wednesday, August 7, 2024, 2:08 PM, al spitzley <kogz23 at yahoo.com> wrote:
> 
> Thanks for the ideas.
> I tried cranking the gain and no luck. Different results each time. Aargh!
> When it ?freezes? with the Tape button lit it will not go into load. The only way to get out of it is to hit the Tape button. Occasionally it completely locks up and I have to restart.
> I?m having issues saving to the factory patch area. If I create a patch on A1, save it, create a different one on A2 (for example) it will save but also save into A1 or any previous patches I?ve just created. So I can?t create different patches when the Patch button is lit. I?m thinking this could be user error and confusion over factory patches vs user patches.
> I?m going to try loading factory patches using a utility eprom I found on the internet. I?ll be away for a few days and will report back.
> Thanks again 
> Al
> 
> 
> Sent from Yahoo Mail for iPhone <https://mail.onelink.me/107872968?pid=nativeplacement&c=Global_Acquisition_YMktg_315_Internal_EmailSignature&af_sub1=Acquisition&af_sub2=Global_YMktg&af_sub3=&af_sub4=100000604&af_sub5=EmailSignature__Static_>
> 
> On Wednesday, August 7, 2024, 11:55 AM, Nathan Trites <nathan at idmclassics.net> wrote:
> 
> On one Jupiter 6 I did, I was convinced the RAM was bad because no matter what there would always be a few corrupt patches that would lock up the synth. Eventually I figured out the patches that failed had to do with the level I was doing the playback at, and it was consistent across every interface I have - the only solution was giving the tape signal an absurd amount of gain thru a preamp. If I recall the dump I got online was already normalized, and the cassette interface on the synth had no issues, so unless the CPU had a problem, it was possibly due to the frequency response of the specific dump or something like that. Ever since then I've done cassette restores on Jupiter 6's by giving it a ton of gain thru a mixer channel, and haven't had any patch dump issues yet. All that to say - don't rule out cranking the gain like crazy. 
> 
> I've also had to do what Tony describes to get JP-6 memory to work correctly 
> 
> Nathan
> 
> On Wed, Aug 7, 2024 at 3:28?AM Tony Allgood via Synth-diy <synth-diy at synth-diy.org <mailto:synth-diy at synth-diy.org>> wrote:
> I have seen similar behaviour before with various JP-6 units over the 
> years. What has always fixed it is going into manual mode. Create a 
> simple standard 'init' patch, something like a classic analogue pluck 
> sound will do. But it doesn't matter - just something you know the sound of.
> 
> Then program that same patch into *every* memory location.
> 
> Now check every patch still sounds the same and no crashes occur.
> 
> Reload the factory patches via tape if you wish.
> 
> However, if it is your own patches you are trying to load, then it could 
> be that it is those that are corrupted. In this case, it is probably 
> better to reprogram those sounds in manual mode.
> 
> Tony
> 
> www.oakleysound.com <http://www.oakleysound.com/>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org <mailto:marketplace at synth-diy.org>
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org <mailto:marketplace at synth-diy.org>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

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From fanwander at mnet-online.de  Thu Aug  8 07:49:07 2024
From: fanwander at mnet-online.de (Florian Anwander)
Date: Thu, 8 Aug 2024 07:49:07 +0200
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <25B13EF2-344E-470B-802C-E47CC1FE81BA@adambaby.com>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
 <25B13EF2-344E-470B-802C-E47CC1FE81BA@adambaby.com>
Message-ID: <6bbb655b-4672-4ec6-ba33-4f10010a1e47@mnet-online.de>

Hello

Am 07.08.24 um 23:41 schrieb Adam (synthDIY):
> My S612 came with a QuikDisk drive (what a monster!) but there was also provision for a "Commodore" cassette interface, not provided as standard on most machines (the port is empty on mine).
>
>
The Firmware-Release 1.3e from Werner Szugat had an option to bring that 
tape interface to the frontpanels out.



Am 07.08.24 um 23:41 schrieb brianw:
> I seriously doubt it. The dump to tape would take so long that it would probably have a 100% chance of error. The size of a synth patch versus the size of a sample is quite a significant difference.
The tape interface was not that slow. The quickdisk is in fact not a 
random access medium with controllable head. It works simply linear like 
a tape, the magnetic disk is moving under the head and the head is moved 
slowly from the center to the edge. If I remember right storing reading 
on tape took around 1.5 times of the quickdisk.

Florian

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From synthdiy at adambaby.com  Thu Aug  8 08:48:27 2024
From: synthdiy at adambaby.com (Adam (synthDIY))
Date: Thu, 8 Aug 2024 16:48:27 +1000
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <6bbb655b-4672-4ec6-ba33-4f10010a1e47@mnet-online.de>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
 <25B13EF2-344E-470B-802C-E47CC1FE81BA@adambaby.com>
 <6bbb655b-4672-4ec6-ba33-4f10010a1e47@mnet-online.de>
Message-ID: <82A99F00-4CEF-4FB9-8E67-3855C546244D@adambaby.com>



> On 8 Aug 2024, at 3:49?PM, Florian Anwander <fanwander at mnet-online.de> wrote:
> 
> Hello
> 
> Am 07.08.24 um 23:41 schrieb Adam (synthDIY):
>> My S612 came with a QuikDisk drive (what a monster!) but there was also provision for a "Commodore" cassette interface, not provided as standard on most machines (the port is empty on mine).
>> 
>> 
> The Firmware-Release 1.3e from Werner Szugat had an option to bring that tape interface to the frontpanels out.


Yes, I think I read about that on your site Florian, many years ago. I never heard much about it later, whether or not it was a practical solution...?


> 
> 
> 
> Am 07.08.24 um 23:41 schrieb brianw:
>> I seriously doubt it. The dump to tape would take so long that it would probably have a 100% chance of error. The size of a synth patch versus the size of a sample is quite a significant difference.
> The tape interface was not that slow. The quickdisk is in fact not a random access medium with controllable head. It works simply linear like a tape, the magnetic disk is moving under the head and the head is moved slowly from the center to the edge. If I remember right storing reading on tape took around 1.5 times of the quickdisk.
> 
> Florian

I see people on Gearspace suggesting the tape dump took nearly as long as Midi Sample Dump! (approximately just under a week or so ;-))

QuikDisk was fairly, er, "quik" but remember we are only talking about samples of a couple of seconds in length!

A


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From mr at analogue.org  Thu Aug  8 09:04:23 2024
From: mr at analogue.org (Mattias Rickardsson)
Date: Thu, 8 Aug 2024 09:04:23 +0200
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CA+owdPsnetpv5fMdFaA6yAcLVFD9_ckg8=Vi607SycV6smrCZQ@mail.gmail.com>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
 <CA+owdPs5QVDEL49pVzAd85XNxVwOyM-824uwEHRh0EiueEr-1A@mail.gmail.com>
 <CA+owdPvRxDzf223ePSxWXpmB1QQT7ES9UHettOMjqerWyPC5Rg@mail.gmail.com>
 <CA+owdPvE5rmee7TMhJ7RFF+=JwWtbjuc7g4oBzHtoLWFH49uHA@mail.gmail.com>
 <CA+owdPsnetpv5fMdFaA6yAcLVFD9_ckg8=Vi607SycV6smrCZQ@mail.gmail.com>
Message-ID: <CAP92RBVZMrw3a6mG5Aan=nY2ZmkDwzPZVK2n21-7ajBD4T7OkA@mail.gmail.com>

Thanks all for the examples and discussion. I'm not much into old samplers
and never expected that quite a lot of instruments used this "detour
solution" after all! :-)

Since the tape dump of an audio snippet sample creates an audio snippet
that takes much MORE time than the original audio snippet, I find it
bizarre/amusing. The trivial alternative would of course be to save the
original audio snippet on audio tape instead, without going via the digital
data encoding. The tape dump method is of course much "better" since it's
lossless, and also might have needed less expensive/messy hardware
solutions back in the day.

All this is somewhat similar (but opposite!) to recording chiptune music or
even other MIDI-sequenced music where all the generative data is available
in a much much smaller amount of information than the resulting audio
recording... that we might even compress to mp3 etc. And it might have been
travelling via the analog realm and back along the way. Here it's the
opposite though: The extremely compact original generative
sequencer/synthesis data is the lossless way of encoding it, while the huge
audio recording is the lossy one.  :-)

Btw, the following additional 4 examples of tape-dump samplers appeared
off-list, it seems:

On Thu, 8 Aug 2024 at 01:48, min struct <min.struct at gmail.com> wrote:

> E-mu SP12 memory's segments, songs and user sounds, and allows to save all
> the data to tape or disc.
> Cassette dump is reportedly very slow (data can also be saved to disc if
> one has a Commodore 64 computer with disc drive)
>
> Le jeu. 8 ao?t 2024 ? 01:42, min struct <min.struct at gmail.com> a ?crit :
>
>> CASIO RZ-1 covered Tape Load and Save for patterns and *samples*
>>
>> Le jeu. 8 ao?t 2024 ? 01:33, min struct <min.struct at gmail.com> a ?crit :
>>
>>> RSF SD140 Sampling Drum Machine
>>>  offers 14 user sampling memories of various lengths, *sample
>>> dump-to-tape* (or via MIDI to a computer or other data recorder)
>>>
>>> Le jeu. 8 ao?t 2024 ? 01:29, min struct <min.struct at gmail.com> a ?crit :
>>>
>>>> AKAI S1000 digital output was designed for backing up the memory (or
>>>> the hard disk) to DAT.
>>>> audio part of the sample was simply ... digital audio, and sample
>>>> parameters were coded like software on cassette by computers...
>>>>
>>>> Le mer. 7 ao?t 2024 ? 23:22, Mattias Rickardsson <mr at analogue.org> a
>>>> ?crit :
>>>>
>>>>> Hi,
>>>>> After some cassette backup discussions, a silly idea came up.
>>>>>
>>>>> Old synths often had tape dump as a means of backing up sounds.
>>>>> Nowadays it's easier to use a sampler or computer than a cassette
>>>>> tape, since it's just audio.
>>>>> Sooo... turning this on its head:
>>>>>
>>>>> Were there ever any old sampler that would let you store sample data
>>>>> as a tape dump? (-:
>>>>>
>>>>> /mr
>>>>>
>>>>
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From andrei.kudryavtsev at gmail.com  Thu Aug  8 09:38:47 2024
From: andrei.kudryavtsev at gmail.com (Andrei Kudryavtsev)
Date: Thu, 8 Aug 2024 00:38:47 -0700
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CAP92RBVZMrw3a6mG5Aan=nY2ZmkDwzPZVK2n21-7ajBD4T7OkA@mail.gmail.com>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
 <CA+owdPs5QVDEL49pVzAd85XNxVwOyM-824uwEHRh0EiueEr-1A@mail.gmail.com>
 <CA+owdPvRxDzf223ePSxWXpmB1QQT7ES9UHettOMjqerWyPC5Rg@mail.gmail.com>
 <CA+owdPvE5rmee7TMhJ7RFF+=JwWtbjuc7g4oBzHtoLWFH49uHA@mail.gmail.com>
 <CA+owdPsnetpv5fMdFaA6yAcLVFD9_ckg8=Vi607SycV6smrCZQ@mail.gmail.com>
 <CAP92RBVZMrw3a6mG5Aan=nY2ZmkDwzPZVK2n21-7ajBD4T7OkA@mail.gmail.com>
Message-ID: <CAL4jy_JLcu39u7tUxErpu2qKwqbDNGuCyTEo30uJZQC2CExJMA@mail.gmail.com>

It doesn't need to be a vintage sampler :) . Teenage Engineering
implemented that on PO-33 and PO-35.

On Thu, Aug 8, 2024 at 12:10?AM Mattias Rickardsson <mr at analogue.org> wrote:

> Thanks all for the examples and discussion. I'm not much into old samplers
> and never expected that quite a lot of instruments used this "detour
> solution" after all! :-)
>
> Since the tape dump of an audio snippet sample creates an audio snippet
> that takes much MORE time than the original audio snippet, I find it
> bizarre/amusing. The trivial alternative would of course be to save the
> original audio snippet on audio tape instead, without going via the digital
> data encoding. The tape dump method is of course much "better" since it's
> lossless, and also might have needed less expensive/messy hardware
> solutions back in the day.
>
> All this is somewhat similar (but opposite!) to recording chiptune music
> or even other MIDI-sequenced music where all the generative data is
> available in a much much smaller amount of information than the resulting
> audio recording... that we might even compress to mp3 etc. And it might
> have been travelling via the analog realm and back along the way. Here it's
> the opposite though: The extremely compact original generative
> sequencer/synthesis data is the lossless way of encoding it, while the huge
> audio recording is the lossy one.  :-)
>
> Btw, the following additional 4 examples of tape-dump samplers appeared
> off-list, it seems:
>
> On Thu, 8 Aug 2024 at 01:48, min struct <min.struct at gmail.com> wrote:
>
>> E-mu SP12 memory's segments, songs and user sounds, and allows to save
>> all the data to tape or disc.
>> Cassette dump is reportedly very slow (data can also be saved to disc if
>> one has a Commodore 64 computer with disc drive)
>>
>> Le jeu. 8 ao?t 2024 ? 01:42, min struct <min.struct at gmail.com> a ?crit :
>>
>>> CASIO RZ-1 covered Tape Load and Save for patterns and *samples*
>>>
>>> Le jeu. 8 ao?t 2024 ? 01:33, min struct <min.struct at gmail.com> a ?crit :
>>>
>>>> RSF SD140 Sampling Drum Machine
>>>>  offers 14 user sampling memories of various lengths, *sample
>>>> dump-to-tape* (or via MIDI to a computer or other data recorder)
>>>>
>>>> Le jeu. 8 ao?t 2024 ? 01:29, min struct <min.struct at gmail.com> a
>>>> ?crit :
>>>>
>>>>> AKAI S1000 digital output was designed for backing up the memory (or
>>>>> the hard disk) to DAT.
>>>>> audio part of the sample was simply ... digital audio, and sample
>>>>> parameters were coded like software on cassette by computers...
>>>>>
>>>>> Le mer. 7 ao?t 2024 ? 23:22, Mattias Rickardsson <mr at analogue.org> a
>>>>> ?crit :
>>>>>
>>>>>> Hi,
>>>>>> After some cassette backup discussions, a silly idea came up.
>>>>>>
>>>>>> Old synths often had tape dump as a means of backing up sounds.
>>>>>> Nowadays it's easier to use a sampler or computer than a cassette
>>>>>> tape, since it's just audio.
>>>>>> Sooo... turning this on its head:
>>>>>>
>>>>>> Were there ever any old sampler that would let you store sample data
>>>>>> as a tape dump? (-:
>>>>>>
>>>>>> /mr
>>>>>>
>>>>> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>


-- 
Andrei Kudryavtsev,
Deftaudio www.deftaudio.com
Manufacturing Luma-1 Drum Machine
<https://www.instagram.com/luma1_drum_machine>

My last album *Two Match - The 1st Fill* on iTunes
<http://itunes.apple.com/us/album/the-1st-fill/id1241529125> and Spotify
<https://open.spotify.com/album/4aM8DzmN5yi4ho1gcmC8ls>
Follow me on Facebook <https://www.facebook.com/andrei.kudryavtsev.5>,
Instagram <https://www.instagram.com/deftaudio/>
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From synthdiy at adambaby.com  Thu Aug  8 09:46:01 2024
From: synthdiy at adambaby.com (Adam (synthDIY))
Date: Thu, 8 Aug 2024 17:46:01 +1000
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CAP92RBVZMrw3a6mG5Aan=nY2ZmkDwzPZVK2n21-7ajBD4T7OkA@mail.gmail.com>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
 <CA+owdPs5QVDEL49pVzAd85XNxVwOyM-824uwEHRh0EiueEr-1A@mail.gmail.com>
 <CA+owdPvRxDzf223ePSxWXpmB1QQT7ES9UHettOMjqerWyPC5Rg@mail.gmail.com>
 <CA+owdPvE5rmee7TMhJ7RFF+=JwWtbjuc7g4oBzHtoLWFH49uHA@mail.gmail.com>
 <CA+owdPsnetpv5fMdFaA6yAcLVFD9_ckg8=Vi607SycV6smrCZQ@mail.gmail.com>
 <CAP92RBVZMrw3a6mG5Aan=nY2ZmkDwzPZVK2n21-7ajBD4T7OkA@mail.gmail.com>
Message-ID: <FD8BF308-EAAE-47B2-A66D-09AB72220E85@adambaby.com>



> On 8 Aug 2024, at 5:04?PM, Mattias Rickardsson <mr at analogue.org> wrote:
> 
>  The tape dump method is of course much "better" since it's lossless, and also might have needed less expensive/messy hardware solutions back in the day.


Ha ha exactly! 
"Makes sense on paper" doesn't it...
but the "lossy" use of these things just adds to their character, musically, of course

(e.g. the S612 has this fabulous function they call "Overdub" where you can record a new sample over the previous one... ad infinitum.. with the sampler making adjustments to the gain each time to compensate... )

A
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From mr at analogue.org  Thu Aug  8 09:47:44 2024
From: mr at analogue.org (Mattias Rickardsson)
Date: Thu, 8 Aug 2024 09:47:44 +0200
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CAL4jy_JLcu39u7tUxErpu2qKwqbDNGuCyTEo30uJZQC2CExJMA@mail.gmail.com>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
 <CA+owdPs5QVDEL49pVzAd85XNxVwOyM-824uwEHRh0EiueEr-1A@mail.gmail.com>
 <CA+owdPvRxDzf223ePSxWXpmB1QQT7ES9UHettOMjqerWyPC5Rg@mail.gmail.com>
 <CA+owdPvE5rmee7TMhJ7RFF+=JwWtbjuc7g4oBzHtoLWFH49uHA@mail.gmail.com>
 <CA+owdPsnetpv5fMdFaA6yAcLVFD9_ckg8=Vi607SycV6smrCZQ@mail.gmail.com>
 <CAP92RBVZMrw3a6mG5Aan=nY2ZmkDwzPZVK2n21-7ajBD4T7OkA@mail.gmail.com>
 <CAL4jy_JLcu39u7tUxErpu2qKwqbDNGuCyTEo30uJZQC2CExJMA@mail.gmail.com>
Message-ID: <CAP92RBUNsvGsxVTBgHt=Q6RQNWSGKvB0YtoP=tGsYMUkvWpBEg@mail.gmail.com>

On Thu, 8 Aug 2024 at 09:39, Andrei Kudryavtsev <
andrei.kudryavtsev at gmail.com> wrote:

> It doesn't need to be a vintage sampler :) . Teenage Engineering
> implemented that on PO-33 and PO-35.
>

Are you sure their products aren't vintage already from the start? ;-)
https://teenage.engineering/products/ep-1320

/mr
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From loscha at gmail.com  Thu Aug  8 10:12:08 2024
From: loscha at gmail.com (Loscha)
Date: Thu, 8 Aug 2024 18:12:08 +1000
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
Message-ID: <CAA25cvepcnH=sbPb=vLBz7ibXy3tQ4=5Jaspya8P9DgG1bbKrg@mail.gmail.com>

I am pretty sure the Casio RZ-1 sampling drum machine can dump it's samples
to cassette.

http://zine.r-massive.com/casio-rz-1-custom-firmware/


On Thu, 8 Aug 2024 at 07:24, Mattias Rickardsson <mr at analogue.org> wrote:

> Hi,
> After some cassette backup discussions, a silly idea came up.
>
> Old synths often had tape dump as a means of backing up sounds.
> Nowadays it's easier to use a sampler or computer than a cassette
> tape, since it's just audio.
> Sooo... turning this on its head:
>
> Were there ever any old sampler that would let you store sample data as a
> tape dump? (-:
>
> /mr
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From modular at go2.pl  Thu Aug  8 13:44:49 2024
From: modular at go2.pl (Roman Sowa)
Date: Thu, 8 Aug 2024 13:44:49 +0200
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <20240807231926.GA26472@gjcp.net>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
 <CC0E98AC-A0BA-4162-982E-F782CC9A3508@audiobanshee.com>
 <20240807231926.GA26472@gjcp.net>
Message-ID: <fd855759-206c-4860-87eb-360af5b122d6@go2.pl>

Using modern modulation techniques like QAM256 one could achieve much 
higher throughput from a cassete. I wouldn't be surprised to see 200kbps 
of clean data after all correction stuff, so that 128kB Commodore loads 
in like 5 seconds.

Roman

W dniu 2024-08-08 o?01:19, Gordonjcp pisze:
> On Wed, Aug 07, 2024 at 02:41:38PM -0700, brianw wrote:
>> I seriously doubt it. The dump to tape would take so long that it would probably have a 100% chance of error. The size of a synth patch versus the size of a sample is quite a significant difference.
> 
> It depends. Home computers with as much as 128kB of RAM used tape for storage, so you could easily store an entire Ensoniq Mirage's worth of sample and program RAM to tape. Using standard ZX tape routines it'd take about 15 minutes to load or save, considerably slower than floppy disk. Even using something like Speedlock would only take that down to about 10-11 minutes.
> 

From mbryant at futurehorizons.com  Thu Aug  8 14:13:00 2024
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Thu, 8 Aug 2024 12:13:00 +0000
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <fd855759-206c-4860-87eb-360af5b122d6@go2.pl>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
 <CC0E98AC-A0BA-4162-982E-F782CC9A3508@audiobanshee.com>
 <20240807231926.GA26472@gjcp.net>
 <fd855759-206c-4860-87eb-360af5b122d6@go2.pl>
Message-ID: <CWLP265MB7132E1F579189E8BA5E39C1EDBB92@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

QAM256 (or any other such technique) depends on a consistent, almost predictable, level of noise.  I suspect cassette noise is truly random so it would drop back to lower levels, in the end a single binary bit and just get the speed we used to get.
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Roman Sowa via Synth-diy <synth-diy at synth-diy.org>
Sent: 08 August 2024 12:44
To: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Sampler with tape dump?

Using modern modulation techniques like QAM256 one could achieve much
higher throughput from a cassete. I wouldn't be surprised to see 200kbps
of clean data after all correction stuff, so that 128kB Commodore loads
in like 5 seconds.

Roman

W dniu 2024-08-08 o 01:19, Gordonjcp pisze:
> On Wed, Aug 07, 2024 at 02:41:38PM -0700, brianw wrote:
>> I seriously doubt it. The dump to tape would take so long that it would probably have a 100% chance of error. The size of a synth patch versus the size of a sample is quite a significant difference.
>
> It depends. Home computers with as much as 128kB of RAM used tape for storage, so you could easily store an entire Ensoniq Mirage's worth of sample and program RAM to tape. Using standard ZX tape routines it'd take about 15 minutes to load or save, considerably slower than floppy disk. Even using something like Speedlock would only take that down to about 10-11 minutes.
>
________________________________________________________
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Submit email to: Synth-diy at synth-diy.org
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From synthmaarten at artefacts.nl  Thu Aug  8 14:22:49 2024
From: synthmaarten at artefacts.nl (Maarten)
Date: Thu, 8 Aug 2024 14:22:49 +0200
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
Message-ID: <e87e0753-3179-45d8-a45f-566a9f86e85b@artefacts.nl>

The AHB Impulse drumcomputer also uses a tape interface to load 
additional drum sounds.

Maarten

Op 7-8-2024 om 23:19 schreef Mattias Rickardsson:
> Hi,
> After some cassette backup discussions, a silly idea came up.
>
> Old synths often had tape dump as a means of backing up sounds.
> Nowadays it's easier to use a sampler or computer than a cassette 
> tape,?since it's just audio.
> Sooo... turning this on its head:
>
> Were there ever any old sampler that would let you store sample?data 
> as a tape dump? (-:
>
> /mr
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

From modular at go2.pl  Thu Aug  8 14:28:53 2024
From: modular at go2.pl (Roman Sowa)
Date: Thu, 8 Aug 2024 14:28:53 +0200
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CWLP265MB7132E1F579189E8BA5E39C1EDBB92@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
 <CC0E98AC-A0BA-4162-982E-F782CC9A3508@audiobanshee.com>
 <20240807231926.GA26472@gjcp.net>
 <fd855759-206c-4860-87eb-360af5b122d6@go2.pl>
 <CWLP265MB7132E1F579189E8BA5E39C1EDBB92@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <70389b4d-64e6-41d6-9bc8-61f10de19ca9@go2.pl>

There's no more truly random medium than "the air" and still QAM64 is 
doing perfectly fine there as in terrestial TV. 256 was maybe tiny 
exaggeration, althogh I'd be tempted to try it hoping for really good 
results if I cared anough.
Don't forget, we (as in "we, humans) have reached theoretical limit of 
56kbs in lousy 3kHz bandwidth of a phone line.

Roman

W dniu 2024-08-08 o?14:13, Mike Bryant pisze:
> QAM256 (or any other such technique) depends on a consistent, almost 
> predictable, level of noise.? I suspect cassette noise is truly random 
> so it would drop back to lower levels, in the end a single binary bit 
> and just get the speed we used to get.
> ------------------------------------------------------------------------
> *From:* Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Roman 
> Sowa via Synth-diy <synth-diy at synth-diy.org>
> *Sent:* 08 August 2024 12:44
> *To:* synth-diy at synth-diy.org <synth-diy at synth-diy.org>
> *Subject:* Re: [sdiy] Sampler with tape dump?
> Using modern modulation techniques like QAM256 one could achieve much
> higher throughput from a cassete. I wouldn't be surprised to see 200kbps
> of clean data after all correction stuff, so that 128kB Commodore loads
> in like 5 seconds.
> 
> Roman
> 
> W dniu 2024-08-08 o?01:19, Gordonjcp pisze:
>> On Wed, Aug 07, 2024 at 02:41:38PM -0700, brianw wrote:
>>> I seriously doubt it. The dump to tape would take so long that it would probably have a 100% chance of error. The size of a synth patch versus the size of a sample is quite a significant difference.
>> 
>> It depends. Home computers with as much as 128kB of RAM used tape for storage, so you could easily store an entire Ensoniq Mirage's worth of sample and program RAM to tape. Using standard ZX tape routines it'd take about 15 minutes to load or save, considerably  slower than floppy disk. Even using something like Speedlock would 
> only take that down to about 10-11 minutes.
>> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/ 
> <https://synth-diy.org/pipermail/synth-diy/>
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy 
> <https://synth-diy.org/mailman/listinfo/synth-diy>
> Selling or trading? Use marketplace at synth-diy.org

From mbryant at futurehorizons.com  Thu Aug  8 15:29:07 2024
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Thu, 8 Aug 2024 13:29:07 +0000
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <70389b4d-64e6-41d6-9bc8-61f10de19ca9@go2.pl>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
 <CC0E98AC-A0BA-4162-982E-F782CC9A3508@audiobanshee.com>
 <20240807231926.GA26472@gjcp.net>
 <fd855759-206c-4860-87eb-360af5b122d6@go2.pl>
 <CWLP265MB7132E1F579189E8BA5E39C1EDBB92@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <70389b4d-64e6-41d6-9bc8-61f10de19ca9@go2.pl>
Message-ID: <CWLP265MB71321A9613EA96CA10F3C78ADBB92@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

Yes I know all about these issues - I used to design ADSL and then VDSL modems which have to adapt around moving interferers, including other modems of course.   The 56kpbs 'analogue' modem speed was only on download so we could put more energy with pre-distortion into the signal at well above 3.4kHz.  This couldn't be done on upload so was limited to 33k.

Terrestrial TV depends on Trellis coded modulation and very long Reed-Solomon (RS) codes that you couldn't use in modems because of latency to get a useable signal out of the mush  These could have been applied to a cassette if they had been invented back then and you had some way of building the huge amount of logic required, but one didn't back then.


________________________________
From: Roman Sowa <modular at go2.pl>
Sent: 08 August 2024 13:28
To: Mike Bryant <mbryant at futurehorizons.com>; synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Sampler with tape dump?

There's no more truly random medium than "the air" and still QAM64 is
doing perfectly fine there as in terrestial TV. 256 was maybe tiny
exaggeration, althogh I'd be tempted to try it hoping for really good
results if I cared anough.
Don't forget, we (as in "we, humans) have reached theoretical limit of
56kbs in lousy 3kHz bandwidth of a phone line.

Roman

W dniu 2024-08-08 o 14:13, Mike Bryant pisze:
> QAM256 (or any other such technique) depends on a consistent, almost
> predictable, level of noise.  I suspect cassette noise is truly random
> so it would drop back to lower levels, in the end a single binary bit
> and just get the speed we used to get.
> ------------------------------------------------------------------------
> *From:* Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Roman
> Sowa via Synth-diy <synth-diy at synth-diy.org>
> *Sent:* 08 August 2024 12:44
> *To:* synth-diy at synth-diy.org <synth-diy at synth-diy.org>
> *Subject:* Re: [sdiy] Sampler with tape dump?
> Using modern modulation techniques like QAM256 one could achieve much
> higher throughput from a cassete. I wouldn't be surprised to see 200kbps
> of clean data after all correction stuff, so that 128kB Commodore loads
> in like 5 seconds.
>
> Roman
>
> W dniu 2024-08-08 o 01:19, Gordonjcp pisze:
>> On Wed, Aug 07, 2024 at 02:41:38PM -0700, brianw wrote:
>>> I seriously doubt it. The dump to tape would take so long that it would probably have a 100% chance of error. The size of a synth patch versus the size of a sample is quite a significant difference.
>>
>> It depends. Home computers with as much as 128kB of RAM used tape for storage, so you could easily store an entire Ensoniq Mirage's worth of sample and program RAM to tape. Using standard ZX tape routines it'd take about 15 minutes to load or save, considerably  slower than floppy disk. Even using something like Speedlock would
> only take that down to about 10-11 minutes.
>>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> <https://synth-diy.org/pipermail/synth-diy/>
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> <https://synth-diy.org/mailman/listinfo/synth-diy>
> Selling or trading? Use marketplace at synth-diy.org
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From hbissell at wowway.com  Thu Aug  8 16:15:05 2024
From: hbissell at wowway.com (Mr&MrsAccount)
Date: Thu, 8 Aug 2024 10:15:05 -0400 (EDT)
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
Message-ID: <816287546.11637265.1723126505201.JavaMail.zimbra@wowway.com>

 
 
 
 
 
have a AGC (automatic gain control) so the first bits would blast the tape before it turns down the gain.? Playing with the gain might or might not do much. In some cases 
the cheap recorders might work better. 
? 
Next we will be repairing those old machines to load our dinosaur synths... 
? 
Harry  
 
 

-----Original Message-----

From: Mattias <mr at analogue.org>
To: Synth <synth-diy at synth-diy.org>
Date: Wednesday, 7 August 2024 5:28 PM EDT
Subject: [sdiy] Sampler with tape dump?

 
 
Hi, After some cassette backup discussions, a silly idea came up. 

 
Old synths often had tape dump as a means of backing up sounds.  
Nowadays it's easier to use a sampler or computer than a cassette tape,?since it's just audio. 
Sooo... turning this on its head: 
 
Were there ever any old sampler that would let you store sample?data as a tape dump? (-: 
 
/mr     
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From hbissell at wowway.com  Thu Aug  8 17:14:15 2024
From: hbissell at wowway.com (Mr&MrsAccount)
Date: Thu, 8 Aug 2024 11:14:15 -0400 (EDT)
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <816287546.11637265.1723126505201.JavaMail.zimbra@wowway.com>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
 <816287546.11637265.1723126505201.JavaMail.zimbra@wowway.com>
Message-ID: <113256459.11727392.1723130055424.JavaMail.zimbra@wowway.com>

 
 
 
 
 
? 
  
 

-----Original Message-----

From: Mr&MrsAccount <hbissell at wowway.com>
To: Mattias <mr at analogue.org>
Cc: Synth <synth-diy at synth-diy.org>
Date: Thursday, 8 August 2024 10:15 AM EDT
Subject: Re: [sdiy] Sampler with tape dump?

 
 
 
 
 
 
have a AGC (automatic gain control) so the first bits would blast the tape before it turns down the gain.? Playing with the gain might or might not do much. In some cases 
the cheap recorders might work better. 

 
Next we will be repairing those old machines to load our dinosaur synths... 

 
Harry 
 
 
From: Mattias <mr at analogue.org>
To: Synth <synth-diy at synth-diy.org>
Date: Wednesday, 7 August 2024 5:28 PM EDT
Subject: [sdiy] Sampler with tape dump?

 
 
Hi, After some cassette backup discussions, a silly idea came up. 

 
Old synths often had tape dump as a means of backing up sounds.  
Nowadays it's easier to use a sampler or computer than a cassette tape,?since it's just audio. 
Sooo... turning this on its head: 
 
Were there ever any old sampler that would let you store sample?data as a tape dump? (-: 
 
/mr         
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From hbissell at wowway.com  Thu Aug  8 18:30:59 2024
From: hbissell at wowway.com (Harry Bissell)
Date: Thu, 8 Aug 2024 12:30:59 -0400
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CAA25cvepcnH=sbPb=vLBz7ibXy3tQ4=5Jaspya8P9DgG1bbKrg@mail.gmail.com>
References: <CAA25cvepcnH=sbPb=vLBz7ibXy3tQ4=5Jaspya8P9DgG1bbKrg@mail.gmail.com>
Message-ID: <9AA7688C-5270-4843-9593-DE81E2B9EB8A@wowway.com>

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From mbryant at futurehorizons.com  Thu Aug  8 18:37:29 2024
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Thu, 8 Aug 2024 16:37:29 +0000
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <9AA7688C-5270-4843-9593-DE81E2B9EB8A@wowway.com>
References: <CAA25cvepcnH=sbPb=vLBz7ibXy3tQ4=5Jaspya8P9DgG1bbKrg@mail.gmail.com>
 <9AA7688C-5270-4843-9593-DE81E2B9EB8A@wowway.com>
Message-ID: <CWLP265MB7132C2A8724A2467EAB3AB14DBB92@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

  *
Sampler data as a tape dump

As in a pile of tape dumped on the floor ?

The only keyboard instrument that used to need two roadies dedicated to it :-)

________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Harry Bissell <hbissell at wowway.com>
Sent: 08 August 2024 17:30
To: Loscha <loscha at gmail.com>
Cc: Synth DIY <Synth-diy at synth-diy.org>
Subject: Re: [sdiy] Sampler with tape dump?

Sampler data as a tape dump. Absolutely. It?s called a Mellotron.


Mr & Mrs Account

On Aug 8, 2024, at 4:20?AM, Loscha via Synth-diy <synth-diy at synth-diy.org> wrote:

?
I am pretty sure the Casio RZ-1 sampling drum machine can dump it's samples to cassette.

http://zine.r-massive.com/casio-rz-1-custom-firmware/


On Thu, 8 Aug 2024 at 07:24, Mattias Rickardsson <mr at analogue.org<mailto:mr at analogue.org>> wrote:
Hi,
After some cassette backup discussions, a silly idea came up.

Old synths often had tape dump as a means of backing up sounds.
Nowadays it's easier to use a sampler or computer than a cassette tape, since it's just audio.
Sooo... turning this on its head:

Were there ever any old sampler that would let you store sample data as a tape dump? (-:

/mr
________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org<mailto:Synth-diy at synth-diy.org>
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________________________________________________________
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From subjectivity at hotmail.com  Thu Aug  8 20:08:47 2024
From: subjectivity at hotmail.com (Dan Snazelle)
Date: Thu, 8 Aug 2024 18:08:47 +0000
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
Message-ID: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>

imagine someone asked you to make some new synth modules.
then imagine that the last time you did so in any quantity above one---  it was 2017.


I am trying to get a handle on what the parts landscape is like now for cost-effective CV control. Back in 2017 the lm13700 was really the only available OTA . I was just starting to work with the ssm2164 at the time but never used it extensively.

In the interim I have built synth circuits but only in quantities of one where cost was no object and I was able to rely on my own extensive parts supply.


So my question is this-- if I am thinking about design for manufacturing?what do you think the best option is?

Has anyone tried the quad ALFA OTA? Is it even readily available? Same for the new SSM2040?.

OR would you just use the 2164 instead?
OR would you just try to make discrete OTAS out of say the  BCM856DS //BCM847BS

thanks for any and all opinions on this.








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From cfo at synthcube.com  Thu Aug  8 20:36:40 2024
From: cfo at synthcube.com (Chris H. Park)
Date: Thu, 8 Aug 2024 18:36:40 +0000
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
Message-ID: <5E4308AC-8A20-4A12-AAD6-5916E8B30EFD@synthcube.com>

Interested to hear the opinions.

Sent from my iPhone

On Aug 8, 2024, at 2:23?PM, Dan Snazelle via Synth-diy <synth-diy at synth-diy.org> wrote:

?
imagine someone asked you to make some new synth modules.
then imagine that the last time you did so in any quantity above one---  it was 2017.


I am trying to get a handle on what the parts landscape is like now for cost-effective CV control. Back in 2017 the lm13700 was really the only available OTA . I was just starting to work with the ssm2164 at the time but never used it extensively.

In the interim I have built synth circuits but only in quantities of one where cost was no object and I was able to rely on my own extensive parts supply.


So my question is this-- if I am thinking about design for manufacturing?what do you think the best option is?

Has anyone tried the quad ALFA OTA? Is it even readily available? Same for the new SSM2040?.

OR would you just use the 2164 instead?
OR would you just try to make discrete OTAS out of say the  BCM856DS //BCM847BS

thanks for any and all opinions on this.








________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
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From mbryant at futurehorizons.com  Thu Aug  8 20:43:27 2024
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Thu, 8 Aug 2024 18:43:27 +0000
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
Message-ID: <CWLP265MB713201155E2476339B9A8376DBB92@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

Surely you just use the more modern more integrated designs.  They will be more accurate and use less board space.
I'm sure Neil J can pipe in here with exact figures on how much more accurate they are.
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Dan Snazelle via Synth-diy <synth-diy at synth-diy.org>
Sent: 08 August 2024 19:08
To: Synth-Diy mailing list <synth-diy at synth-diy.org>
Subject: [sdiy] Best AVAILABLE OTA for building new designs?

imagine someone asked you to make some new synth modules.
then imagine that the last time you did so in any quantity above one---  it was 2017.


I am trying to get a handle on what the parts landscape is like now for cost-effective CV control. Back in 2017 the lm13700 was really the only available OTA . I was just starting to work with the ssm2164 at the time but never used it extensively.

In the interim I have built synth circuits but only in quantities of one where cost was no object and I was able to rely on my own extensive parts supply.


So my question is this-- if I am thinking about design for manufacturing?what do you think the best option is?

Has anyone tried the quad ALFA OTA? Is it even readily available? Same for the new SSM2040?.

OR would you just use the 2164 instead?
OR would you just try to make discrete OTAS out of say the  BCM856DS //BCM847BS

thanks for any and all opinions on this.








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From music at atypical.net  Thu Aug  8 20:50:44 2024
From: music at atypical.net (Joan Touzet)
Date: Thu, 8 Aug 2024 14:50:44 -0400
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
Message-ID: <dd4fd251-8057-4d1a-a517-315f97974d8e@atypical.net>


On 2024-08-08 14:08, Dan Snazelle via Synth-diy wrote:
> imagine someone asked you to make some new synth modules.
> then imagine that the last time you did so in any quantity above 
> one---? it was 2017.
>
>
> I am trying to get a handle on what the parts landscape is like now 
> for cost-effective CV control. Back in 2017 the lm13700 was really the 
> only available OTA . I was just starting to work with the ssm2164 at 
> the time but never used it extensively.


It may just be my opinion, but...why /not/ go with what you know?


LM13700(M) is still in production by TI and not expensive in quantity -- 
cheaper than the other options you mention. TI themselves will even sell 
them to you, e.g. 100 @ US$0.741 each. Coolaudio (Behringer)'s V13700 is 
about about the same price, ~US$0.92. Compare with SSI2140 at e.g. $2.79 
each in that quantity.


Since this is DFM, I'm going to assume SOIC / SSOP / etc. vs. DIP is not 
an obstruction for you.


Can't go wrong with the SSI2140 though, or the V2044A, or even the 
AS2164/33x0 devices -- assuming the increased BOM cost is justified by 
the advantages of the new devices, and you're not trying to colour 
outside the lines that they draw.
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From gordonjcp at gjcp.net  Thu Aug  8 21:12:07 2024
From: gordonjcp at gjcp.net (Gordonjcp)
Date: Thu, 8 Aug 2024 20:12:07 +0100
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
Message-ID: <20240808191207.GA1915@gjcp.net>

On Thu, Aug 08, 2024 at 06:08:47PM +0000, Dan Snazelle via Synth-diy wrote:
> imagine someone asked you to make some new synth modules.
> then imagine that the last time you did so in any quantity above one---  it was 2017.
> 
> 
> I am trying to get a handle on what the parts landscape is like now for cost-effective CV control. Back in 2017 the lm13700 was really the only available OTA . I was just starting to work with the ssm2164 at the time but never used it extensively.
> 

Today the LM13700 is really the only available OTA worth bothering about. You can find others, but why muck about? It's a bit old and clunky but then so are Honda GX industrial engines, and there's a bloody good reason why they're still in production.

-- 
Gordonjcp


From ijfritz at comcast.net  Thu Aug  8 21:18:36 2024
From: ijfritz at comcast.net (Ian Fritz)
Date: Thu, 8 Aug 2024 13:18:36 -0600
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
Message-ID: <3CFA2710-0A32-45BD-BAF3-B888D433D9AB@comcast.net>

CA3280 from alfa works well. I checked a few out in my standard test arrangement.

Ian

Ian

> On Aug 8, 2024, at 12:10?PM, Dan Snazelle via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> ?
> imagine someone asked you to make some new synth modules.
> then imagine that the last time you did so in any quantity above one---  it was 2017. 
> 
> 
> I am trying to get a handle on what the parts landscape is like now for cost-effective CV control. Back in 2017 the lm13700 was really the only available OTA . I was just starting to work with the ssm2164 at the time but never used it extensively.
> 
> In the interim I have built synth circuits but only in quantities of one where cost was no object and I was able to rely on my own extensive parts supply. 
> 
> 
> So my question is this-- if I am thinking about design for manufacturing?what do you think the best option is? 
> 
> Has anyone tried the quad ALFA OTA? Is it even readily available? Same for the new SSM2040?.  
> 
> OR would you just use the 2164 instead? 
> OR would you just try to make discrete OTAS out of say the  BCM856DS //BCM847BS
> 
> thanks for any and all opinions on this. 
> 
> 
> 
> 
> 
> 
> 
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
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From mbryant at futurehorizons.com  Thu Aug  8 21:24:21 2024
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Thu, 8 Aug 2024 19:24:21 +0000
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <20240808191207.GA1915@gjcp.net>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <20240808191207.GA1915@gjcp.net>
Message-ID: <CWLP265MB7132C5D67331557555204D13DBB92@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>


Actually the GX had a total redesign introduced in 2022 to meet the latest EU regulations.  You can still use the old ones (for now) but it's illegal to sell them.   So it's not really the same engine at all.


________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Gordonjcp <gordonjcp at gjcp.net>
Sent: 08 August 2024 20:12
To: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?

Today the LM13700 is really the only available OTA worth bothering about. You can find others, but why muck about? It's a bit old and clunky but then so are Honda GX industrial engines, and there's a bloody good reason why they're still in production.

--
Gordonjcp

________________________________________________________
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From nathan at idmclassics.net  Thu Aug  8 23:43:43 2024
From: nathan at idmclassics.net (Nathan Trites)
Date: Thu, 8 Aug 2024 17:43:43 -0400
Subject: [sdiy] Roland Jupiter 6 issues
In-Reply-To: <4E04F604-2BE1-4AF5-815D-166C1A3D4C90@adambaby.com>
References: <581936990.2448700.1722995972304.ref@mail.yahoo.com>
 <581936990.2448700.1722995972304@mail.yahoo.com>
 <3521001d-73c8-4a43-8f56-681f4c5ea034@gmail.com>
 <CAHy3N6B-Nj=cs_RZa1hvSrsNOPMKuyYdj0ZGy_eCZxNJqNfYkw@mail.gmail.com>
 <676353605.2660928.1723064932689@mail.yahoo.com>
 <215800599.2717459.1723083889354@mail.yahoo.com>
 <4E04F604-2BE1-4AF5-815D-166C1A3D4C90@adambaby.com>
Message-ID: <CAHy3N6DF29HLAz=V-bU4xguFZPFFtu+VxNrpuUGv2MzuC=mB-g@mail.gmail.com>

Yup - the memory naming on the 6 is confusing and obscures the
relationship. Patch Preset and Patch Memory have what gets called a
Performance/Patch or Patch/Tone relationship on some other synths.

Expanding on what Adam said since I had this typed up yesterday but never
sent... "Patch Preset" (Preset switch ON. Bank A/B/C/D & memory 1-8)
remembers the split/layer configuration, arp settings, and the sound
assignment to the lower/upper, etc. Patch Memory (Preset switch OFF, then
your bank & memory slot selection) is the actual sound being used on the
Patch Preset. A Patch Preset calls 1 or 2 tones from Patch Memory.

I'm not 100% on this and would need to check my JP6 sometime, but I believe
the behavior Al is seeing is normal because if you modify Patch Preset A1,
which is calling Patch Memory A1 and A2, when you make changes and save it
to Patch Preset A2 its also overwriting Patch Memory A1 and A2.

Al, what's your playback device for the tape backup?

Nathan

On Wed, Aug 7, 2024 at 11:13?PM Adam (synthDIY) <synthdiy at adambaby.com>
wrote:

> When you say "Patch led" are you referring to the Patch Preset LED?
> I don't own a JP6 but on the JP8 Roland employ a potentially confusing
> terminology, and I think they persisted with the JP6:
> A "patch" is a single memory slot containing the synth voice parameters
> for VCO VCF VCA etc.
> A "Patch Preset" is a special memory that holds two such patches along
> with their voice assignments/splits/glide etc
>
> A
>
> On 8 Aug 2024, at 12:24?PM, al spitzley via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
> A quick question for Tony. When you say to program all the patches with an
> Init patch are you referring to that the Factory patches with the Patch led
> lit?
> Cheers
> Al
>
>
> Sent from Yahoo Mail for iPhone
> <https://mail.onelink.me/107872968?pid=nativeplacement&c=Global_Acquisition_YMktg_315_Internal_EmailSignature&af_sub1=Acquisition&af_sub2=Global_YMktg&af_sub3=&af_sub4=100000604&af_sub5=EmailSignature__Static_>
>
> On Wednesday, August 7, 2024, 2:08 PM, al spitzley <kogz23 at yahoo.com>
> wrote:
>
> Thanks for the ideas.
> I tried cranking the gain and no luck. Different results each time. Aargh!
> When it ?freezes? with the Tape button lit it will not go into load. The
> only way to get out of it is to hit the Tape button. Occasionally it
> completely locks up and I have to restart.
> I?m having issues saving to the factory patch area. If I create a patch on
> A1, save it, create a different one on A2 (for example) it will save but
> also save into A1 or any previous patches I?ve just created. So I can?t
> create different patches when the Patch button is lit. I?m thinking this
> could be user error and confusion over factory patches vs user patches.
> I?m going to try loading factory patches using a utility eprom I found on
> the internet. I?ll be away for a few days and will report back.
> Thanks again
> Al
>
>
> Sent from Yahoo Mail for iPhone
> <https://mail.onelink.me/107872968?pid=nativeplacement&c=Global_Acquisition_YMktg_315_Internal_EmailSignature&af_sub1=Acquisition&af_sub2=Global_YMktg&af_sub3=&af_sub4=100000604&af_sub5=EmailSignature__Static_>
>
> On Wednesday, August 7, 2024, 11:55 AM, Nathan Trites <
> nathan at idmclassics.net> wrote:
>
> On one Jupiter 6 I did, I was convinced the RAM was bad because no matter
> what there would always be a few corrupt patches that would lock up the
> synth. Eventually I figured out the patches that failed had to do with the
> level I was doing the playback at, and it was consistent across every
> interface I have - the only solution was giving the tape signal an absurd
> amount of gain thru a preamp. If I recall the dump I got online was already
> normalized, and the cassette interface on the synth had no issues, so
> unless the CPU had a problem, it was possibly due to the frequency response
> of the specific dump or something like that. Ever since then I've done
> cassette restores on Jupiter 6's by giving it a ton of gain thru a mixer
> channel, and haven't had any patch dump issues yet. All that to say - don't
> rule out cranking the gain like crazy.
>
> I've also had to do what Tony describes to get JP-6 memory to work
> correctly
>
> Nathan
>
> On Wed, Aug 7, 2024 at 3:28?AM Tony Allgood via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
> I have seen similar behaviour before with various JP-6 units over the
> years. What has always fixed it is going into manual mode. Create a
> simple standard 'init' patch, something like a classic analogue pluck
> sound will do. But it doesn't matter - just something you know the sound
> of.
>
> Then program that same patch into *every* memory location.
>
> Now check every patch still sounds the same and no crashes occur.
>
> Reload the factory patches via tape if you wish.
>
> However, if it is your own patches you are trying to load, then it could
> be that it is those that are corrupted. In this case, it is probably
> better to reprogram those sounds in manual mode.
>
> Tony
>
> www.oakleysound.com
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
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>
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From dixon at mail.ubc.ca  Fri Aug  9 01:00:05 2024
From: dixon at mail.ubc.ca (David G Dixon)
Date: Thu, 8 Aug 2024 16:00:05 -0700
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
Message-ID: <89C86B9D456F4083A8E99F4CD54B9450@david78c70950b>

My answer to those questions is very simple: 2164.  I haven't used an OTA for 12 years.  And I am constantly discovering new and exciting ways to use 2164.  Just recently, I figured out how to control many different 2164s as linear amplifiers from a single 2164 logarithmic source.  They are exceptionally easy to implement in some very elaborate control schemes, as long as you locally buffer the CV.  And they make THE BEST multipliers, if you're clever.
 
I'm just in the process of buying 1000 V2164Ds, so if anybody needs a few for a really good price, hit me up privately.

  _____  

From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org] On Behalf Of Dan Snazelle via Synth-diy
Sent: Thursday, August 08, 2024 11:09 AM
To: Synth-Diy mailing list
Subject: [sdiy] Best AVAILABLE OTA for building new designs?


[CAUTION: Non-UBC Email]	
imagine someone asked you to make some new synth modules.
then imagine that the last time you did so in any quantity above one---  it was 2017. 


I am trying to get a handle on what the parts landscape is like now for cost-effective CV control. Back in 2017 the lm13700 was really the only available OTA . I was just starting to work with the ssm2164 at the time but never used it extensively.

In the interim I have built synth circuits but only in quantities of one where cost was no object and I was able to rely on my own extensive parts supply. 


So my question is this-- if I am thinking about design for manufacturing?what do you think the best option is? 

Has anyone tried the quad ALFA OTA? Is it even readily available? Same for the new SSM2040?.  

OR would you just use the 2164 instead? 
OR would you just try to make discrete OTAS out of say the  BCM856DS //BCM847BS

thanks for any and all opinions on this. 








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From mskala at northcoastsynthesis.com  Fri Aug  9 05:03:16 2024
From: mskala at northcoastsynthesis.com (mskala at northcoastsynthesis.com)
Date: Thu, 8 Aug 2024 23:03:16 -0400 (EDT)
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <89C86B9D456F4083A8E99F4CD54B9450@david78c70950b>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <89C86B9D456F4083A8E99F4CD54B9450@david78c70950b>
Message-ID: <alpine.LNX.2.20.2408082301030.7754@kharasan.bonobo-conspiracy.ca>

On Thu, 8 Aug 2024, David G Dixon via Synth-diy wrote:

> ?My answer to those questions is very simple:?2164.? I haven't used an OTA
> for 12 years.? And I am constantly discovering new and exciting ways to use

I get some value out of having differential inputs on LM13700s, for
instance to build leapfrog-topology filters.  It's a shame that there
don't seem to be many 2164-style VCAs with those.

-- 
Matthew Skala
North Coast Synthesis Ltd.

From modular at go2.pl  Fri Aug  9 12:11:11 2024
From: modular at go2.pl (Roman Sowa)
Date: Fri, 9 Aug 2024 12:11:11 +0200
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
Message-ID: <a6acb418-0eda-4358-886e-0a309dc18dc7@go2.pl>

Sadly, the LM13700 is still the best option. Cheaper by a magnitude than 
anything else. And easily available in large quantities. Last time I 
checked TI had around 200k in stock. If only it was made in nicer 
package, like for example WQFN, SOT23-16 or at least TSSOP. But no, they 
need to promote large SOIC like it's 1990.

Making discrete OTA with dual transistors might be tempting, but will be 
more expensive and I'm not sure if it's possible to make it smaller than 
space taken by LM13700 in SOIC.

Roman


W dniu 2024-08-08 o?20:08, Dan Snazelle via Synth-diy pisze:
> imagine someone asked you to make some new synth modules.
> then imagine that the last time you did so in any quantity above one---  
> it was 2017.
> 
> 
> I am trying to get a handle on what the parts landscape is like now for 
> cost-effective CV control. Back in 2017 the lm13700 was really the only 
> available OTA . I was just starting to work with the ssm2164 at the time 
> but never used it extensively.
> 
> In the interim I have built synth circuits but only in quantities of one 
> where cost was no object and I was able to rely on my own extensive 
> parts supply.
> 
> 
> So my question is this-- if I am thinking about design for 
> manufacturing?what do you think the best option is?
> 
> Has anyone tried the quad ALFA OTA? Is it even readily available? Same 
> for the new SSM2040?.
> 
> OR would you just use the 2164 instead?
> OR would you just try to make discrete OTAS out of say the ?BCM856DS 
> //BCM847BS
> 
> thanks for any and all opinions on this.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

From tom at electricdruid.net  Fri Aug  9 13:20:29 2024
From: tom at electricdruid.net (Tom Wiltshire)
Date: Fri, 9 Aug 2024 12:20:29 +0100
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
Message-ID: <00E03A3C-E7A5-4C78-A3B1-992C75D43D56@electricdruid.net>

I'd say the situation is a *lot* better than it was in 2017. There are three manufacturers of synth chips, beyond TI still banging out the LM13700 (but only in SMD these days - DIP version is no longer available).

Alfa Rpar:
They're making a load of clones of many of the old CEM designs, including the 3310, 3320, 3330, 3340, 3350, 3360, 3372(with additions) and others. They also make the quad 13700 clone you noticed, which is four of the 13700 OTA without the darlington buffer, and also a 3280 OTA clone. There's also an excellent 3080 clone, but it's a bit expensive and probably not cost-effective for using large numbers. And then there's the 2164 too.
They've also done some new designs which push the envelope a bit, like the AS3363 which is a whole bunch of interconnected VCAs - some kind of crazy programmable mod matrix on a chip? Or a multi-4-quad-multiplier? It's an interesting chip, but I just can't work out exactly *what* to do with it!
There's also some old-school matched-pairs if you want to go back to basics.

Coolaudio:
Coolaudio also make clones of some of the CEM stuff, the 3320 and the 3340, plus the 13700 and 2164.

Sound Semiconductor:
They've started making new versions of various SSM chips (2040 and 2044 notably) but also producing new and improved designs that go beyond, including an amazing oscillator chip.

In short, there's an absolute ton of stuff out there these days. Most cost effective is probably the 2164 quad VCA, and the 13700 dual OTA.

HTH,
Tom

==================
       Electric Druid
Synth & Stompbox DIY
==================



> On 8 Aug 2024, at 19:08, Dan Snazelle via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> imagine someone asked you to make some new synth modules.
> then imagine that the last time you did so in any quantity above one---  it was 2017. 
> 
> 
> I am trying to get a handle on what the parts landscape is like now for cost-effective CV control. Back in 2017 the lm13700 was really the only available OTA . I was just starting to work with the ssm2164 at the time but never used it extensively.
> 
> In the interim I have built synth circuits but only in quantities of one where cost was no object and I was able to rely on my own extensive parts supply. 
> 
> 
> So my question is this-- if I am thinking about design for manufacturing?what do you think the best option is? 
> 
> Has anyone tried the quad ALFA OTA? Is it even readily available? Same for the new SSM2040?.  
> 
> OR would you just use the 2164 instead? 
> OR would you just try to make discrete OTAS out of say the  BCM856DS //BCM847BS
> 
> thanks for any and all opinions on this. 
> 
> 
> 
> 
> 
> 
> 
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
> View archive at: https://synth-diy.org/pipermail/synth-diy/ <https://synth-diy.org/pipermail/synth-diy/>
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy <https://synth-diy.org/mailman/listinfo/synth-diy>
> Selling or trading? Use marketplace at synth-diy.org <mailto:marketplace at synth-diy.org>
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From markverbos at gmail.com  Fri Aug  9 17:50:19 2024
From: markverbos at gmail.com (mark verbos)
Date: Fri, 9 Aug 2024 17:50:19 +0200
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
Message-ID: <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>

Dan,

I?ve been using the AS2164 only when I need the exponential response. If I need linear VCAs I now use the AS3364, which is more or less a clone of the SSM2024. That?s the same pinout more or less as the SSM2164 but has linear response. So, it?s very easy to use, pretrimmed, quiet, CV referenced to ground, summing node signal ins, doesn?t require all of those 560p caps. That works out great when lots of VCAs are needed, Some people were really turned off by the 1% harmonic distortion, but I have yet to notice an distortion on a synth circuit. 

https://www.alfarzpp.lv/eng/sc/AS3364.pdf?
AS3364
PDF Document ? 494 KB

Mark




> On Aug 8, 2024, at 8:08?PM, Dan Snazelle via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> imagine someone asked you to make some new synth modules.
> then imagine that the last time you did so in any quantity above one---  it was 2017. 
> 
> 
> I am trying to get a handle on what the parts landscape is like now for cost-effective CV control. Back in 2017 the lm13700 was really the only available OTA . I was just starting to work with the ssm2164 at the time but never used it extensively.
> 
> In the interim I have built synth circuits but only in quantities of one where cost was no object and I was able to rely on my own extensive parts supply. 
> 
> 
> So my question is this-- if I am thinking about design for manufacturing?what do you think the best option is? 
> 
> Has anyone tried the quad ALFA OTA? Is it even readily available? Same for the new SSM2040?.  
> 
> OR would you just use the 2164 instead? 
> OR would you just try to make discrete OTAS out of say the  BCM856DS //BCM847BS
> 
> thanks for any and all opinions on this. 
> 
> 
> 
> 
> 
> 
> 
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

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From dixon at mail.ubc.ca  Fri Aug  9 18:31:28 2024
From: dixon at mail.ubc.ca (David G Dixon)
Date: Fri, 9 Aug 2024 09:31:28 -0700
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
Message-ID: <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>

That sounds great.  My only issue is price -- The AS3364 seems to cost about $7 or more, depending on the source, and it does not seem to be possible to buy them directly from Alfa -- at least, I don't see any obvious way to do so from their website.
 
My latest project is going to require about 250 2164 ICs.  That's not a problem given what I'm paying for them.  Yes, in all but the filter application, the 2164s are all linearized, but I'm paying about 23 cents for TL074s and about 1 cent for 561 caps, so from a cost perspective, it just doesn't make much sense.  Linearizing 2164 does add an inch or so to the PCB real estate, but I'm sending the same voltage to a large number (48) of 2164s, so even though they are linearized, only one logarithmic amplifier is needed for all of those 2164s.  I do need to buffer those CVs locally, so there is a TL074 sitting next to the 2164, but I would need to do that with the 3364 as well (the datasheet is silent on the input impedance of the control pins (big negative issue for me), but I presume that it is measured in kilo-ohms, not tera-ohms).  And, I'm getting four linearized amplifiers from each 2164 this way as well, rather than the customary two.
 
I also (mostly now) use the 2164 as a four-quadrant (or variable-quadrant) multiplier, and it is not clear whether the 3364 is amenable to that application.
 
If I could get the AS3364 for less than $2 each, then I'd probably get more serious about using them.

  _____  

From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org] On Behalf Of mark verbos via Synth-diy
Sent: Friday, August 09, 2024 8:50 AM
To: Dan Snazelle
Cc: synth-diy at synth-diy.org
Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?


[CAUTION: Non-UBC Email]	
Dan, 

I?ve been using the AS2164 only when I need the exponential response. If I need linear VCAs I now use the AS3364, which is more or less a clone of the SSM2024. That?s the same pinout more or less as the SSM2164 but has linear response. So, it?s very easy to use, pretrimmed, quiet, CV referenced to ground, summing node signal ins, doesn?t require all of those 560p caps. That works out great when lots of VCAs are needed, Some people were really turned off by the 1% harmonic distortion, but I have yet to notice an distortion on a synth circuit. 

 <https://www.alfarzpp.lv/eng/sc/AS3364.pdf> 
preview.png	


 <https://www.alfarzpp.lv/eng/sc/AS3364.pdf> AS3364
 <https://www.alfarzpp.lv/eng/sc/AS3364.pdf> PDF Document ? 494 KB

Mark





On Aug 8, 2024, at 8:08?PM, Dan Snazelle via Synth-diy <synth-diy at synth-diy.org> wrote:

imagine someone asked you to make some new synth modules.
then imagine that the last time you did so in any quantity above one---  it was 2017. 


I am trying to get a handle on what the parts landscape is like now for cost-effective CV control. Back in 2017 the lm13700 was really the only available OTA . I was just starting to work with the ssm2164 at the time but never used it extensively.

In the interim I have built synth circuits but only in quantities of one where cost was no object and I was able to rely on my own extensive parts supply. 


So my question is this-- if I am thinking about design for manufacturing?what do you think the best option is? 

Has anyone tried the quad ALFA OTA? Is it even readily available? Same for the new SSM2040?.  

OR would you just use the 2164 instead? 
OR would you just try to make discrete OTAS out of say the  BCM856DS //BCM847BS

thanks for any and all opinions on this. 








________________________________________________________
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From rainer at buchty.net  Fri Aug  9 19:53:51 2024
From: rainer at buchty.net (Rainer Buchty)
Date: Fri, 9 Aug 2024 19:53:51 +0200 (CEST)
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <70389b4d-64e6-41d6-9bc8-61f10de19ca9@go2.pl>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
 <CC0E98AC-A0BA-4162-982E-F782CC9A3508@audiobanshee.com>
 <20240807231926.GA26472@gjcp.net>
 <fd855759-206c-4860-87eb-360af5b122d6@go2.pl>
 <CWLP265MB7132E1F579189E8BA5E39C1EDBB92@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <70389b4d-64e6-41d6-9bc8-61f10de19ca9@go2.pl>
Message-ID: <4b0a0039-8ae6-1199-7be6-a010d6ecd903@buchty.net>

On Thu, 8 Aug 2024, Roman Sowa via Synth-diy wrote:

> Don't forget, we (as in "we, humans) have reached theoretical limit of 
> 56kbs in lousy 3kHz bandwidth of a phone line.

Even 64k, considering European ISDN using a UK0 modem aka NTBA.

But both approaches required a "fully digital" switchboard, whatever 
that meant in the electrical sense.

With classical analog switchboards (or, like I had back then, a single 
4km long wire connecting me exclusively to what started as a BBS and 
later turned into an internet provider), it was 33k6 at best.

Which of course is still a speedup to 10 compared to the fasted tape 
routines I saw in use during home-computer times.

(These days, I'm sitting on a more than 1km long line and German Telekom 
is utterly amazed that ADSL16, i.e. 16M/2M, is working without issues. 
Pure black magic compared to earlier 1200/75 -- bps, that is -- times.)

Rainer

From chromatest at chromatest.net  Fri Aug  9 22:34:32 2024
From: chromatest at chromatest.net (Chromatest J. Pantsmaker)
Date: Fri, 9 Aug 2024 13:34:32 -0700
Subject: [sdiy] Repair part question, Korg DDM-110/220 buttons
In-Reply-To: <8877E459-9426-4048-ACFE-3B0205143740@me.com>
References: <8877E459-9426-4048-ACFE-3B0205143740@me.com>
Message-ID: <CADpm=3Ezmk0wa6wwo98egD=n=-WnuoKDGpH0K1x8UarMYpkjgA@mail.gmail.com>

Hello all,
This thread got me thinking about my DDM-220 so I pulled it out.
Everything appears to work on it fine except it won't play patterns.  When
I press Start, it will play the first step and then "pause".  I have tried
slaving it from my DM-110 and I get the same results.  At first I thought
something was holding the stop low, but now I'm thinking it's not getting
any tempo clock.  When set to internal, the Tempo LED does not light.  When
set to external, the Tempo LED tracks with the DDM-110's tempo knob, but it
still doesn't play beyond the first step.

I'm suspecting the 4066 is the culprit, or possibly IC-9 (4013) is the
culprit, but I'm otherwise unsure.
[image: image.png]



On Sat, Jul 13, 2024 at 6:39?AM Benjamin Tremblay via Synth-diy <
synth-diy at synth-diy.org> wrote:

> Hi, I got me a Korg Super Drums off eBay.
> It looks just like the one I had in 1985 before I went crazy with the
> soldering iron and circuit bent the clock.
> It was DOA. I was about to give up on it when I noticed hairline cracks
> around one screw hole in the board. Was able to fix them and then it booted
> up properly.
> But it still seemed dead. Until I almost accidentally closed one of the
> switch contacts with a tool, and it responded. (In fact it?s so snappy I
> could be lazy and trigger the switches with MIDI via 4066 ics and it would
> probably respond at a high speed.)
>
> Looks like very fine hair and dust, like Persian cat dander, is coated
> around the knobs and switches.
> So anyway I found this link on polynomial showing how to crack the
> switches apart and clean them with a q-tip. I have some black goo I used to
> permanently fix an Alesis MMT-8 and so I intend to coat the rubber contacts
> with this good stuff.
>
> But just wondering: Does anyone know what kind of switch this is? (See
> photo on polynomial Repair Blog). To me it looks too good to not be an
> Alps, but it?s not a keyboard switch, is it?
> Whatever it is it?s kinda cool, as long as you don?t have cats.
>
> It seems like a lot of these kinds of parts have vanished from the storage
> bins and there?s nothing that would take its place.
>
> Ben
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From btremblay at me.com  Sat Aug 10 02:37:55 2024
From: btremblay at me.com (Benjamin Tremblay)
Date: Fri, 9 Aug 2024 20:37:55 -0400
Subject: [sdiy] Repair part question, Korg DDM-110/220 buttons
In-Reply-To: <CADpm=3Ezmk0wa6wwo98egD=n=-WnuoKDGpH0K1x8UarMYpkjgA@mail.gmail.com>
References: <8877E459-9426-4048-ACFE-3B0205143740@me.com>
 <CADpm=3Ezmk0wa6wwo98egD=n=-WnuoKDGpH0K1x8UarMYpkjgA@mail.gmail.com>
Message-ID: <079A3289-A707-4B2B-9A54-64CEC1639120@me.com>

My DDM-110 was like that when I got it off ebay. 
There was a crack on the control panel PCB next to a screw. I had to bridge about 4 traces and then the tempo light started to throb.
Remove the screws and the paper screen and look for cracks. 

> On Aug 9, 2024, at 4:34?PM, Chromatest J. Pantsmaker <chromatest at chromatest.net> wrote:
> 
> Hello all,
> This thread got me thinking about my DDM-220 so I pulled it out.  Everything appears to work on it fine except it won't play patterns.  When I press Start, it will play the first step and then "pause".  I have tried slaving it from my DM-110 and I get the same results.  At first I thought something was holding the stop low, but now I'm thinking it's not getting any tempo clock.  When set to internal, the Tempo LED does not light.  When set to external, the Tempo LED tracks with the DDM-110's tempo knob, but it still doesn't play beyond the first step.
> 
> I'm suspecting the 4066 is the culprit, or possibly IC-9 (4013) is the culprit, but I'm otherwise unsure.
> <image.png>
> 
> 
> 
> On Sat, Jul 13, 2024 at 6:39?AM Benjamin Tremblay via Synth-diy <synth-diy at synth-diy.org <mailto:synth-diy at synth-diy.org>> wrote:
>> Hi, I got me a Korg Super Drums off eBay.
>> It looks just like the one I had in 1985 before I went crazy with the soldering iron and circuit bent the clock.
>> It was DOA. I was about to give up on it when I noticed hairline cracks around one screw hole in the board. Was able to fix them and then it booted up properly.
>> But it still seemed dead. Until I almost accidentally closed one of the switch contacts with a tool, and it responded. (In fact it?s so snappy I could be lazy and trigger the switches with MIDI via 4066 ics and it would probably respond at a high speed.)
>> 
>> Looks like very fine hair and dust, like Persian cat dander, is coated around the knobs and switches. 
>> So anyway I found this link on polynomial showing how to crack the switches apart and clean them with a q-tip. I have some black goo I used to permanently fix an Alesis MMT-8 and so I intend to coat the rubber contacts with this good stuff.
>> 
>> But just wondering: Does anyone know what kind of switch this is? (See photo on polynomial Repair Blog). To me it looks too good to not be an Alps, but it?s not a keyboard switch, is it?
>> Whatever it is it?s kinda cool, as long as you don?t have cats.
>> 
>> It seems like a lot of these kinds of parts have vanished from the storage bins and there?s nothing that would take its place.
>> 
>> Ben
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org <mailto:marketplace at synth-diy.org>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

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From declareupdate at gmail.com  Sat Aug 10 02:42:50 2024
From: declareupdate at gmail.com (Chris McDowell)
Date: Fri, 9 Aug 2024 19:42:50 -0500
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
Message-ID: <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>

Alfa is usually pretty responsive to direct inquiries. I've bought a whole bunch of their 2164s. 

At least a year-ish ago, AS3364 was $2.90 @ 100, $1.85 > 1000

Chris McDowell 
> On Aug 9, 2024, at 11:31 AM, David G Dixon via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> That sounds great.  My only issue is price -- The AS3364 seems to cost about $7 or more, depending on the source, and it does not seem to be possible to buy them directly from Alfa -- at least, I don't see any obvious way to do so from their website.
>  
> My latest project is going to require about 250 2164 ICs.  That's not a problem given what I'm paying for them.  Yes, in all but the filter application, the 2164s are all linearized, but I'm paying about 23 cents for TL074s and about 1 cent for 561 caps, so from a cost perspective, it just doesn't make much sense.  Linearizing 2164 does add an inch or so to the PCB real estate, but I'm sending the same voltage to a large number (48) of 2164s, so even though they are linearized, only one logarithmic amplifier is needed for all of those 2164s.  I do need to buffer those CVs locally, so there is a TL074 sitting next to the 2164, but I would need to do that with the 3364 as well (the datasheet is silent on the input impedance of the control pins (big negative issue for me), but I presume that it is measured in kilo-ohms, not tera-ohms).  And, I'm getting four linearized amplifiers from each 2164 this way as well, rather than the customary two.
>  
> I also (mostly now) use the 2164 as a four-quadrant (or variable-quadrant) multiplier, and it is not clear whether the 3364 is amenable to that application.
>  
> If I could get the AS3364 for less than $2 each, then I'd probably get more serious about using them.
> 
> From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org] On Behalf Of mark verbos via Synth-diy
> Sent: Friday, August 09, 2024 8:50 AM
> To: Dan Snazelle
> Cc: synth-diy at synth-diy.org <mailto:synth-diy at synth-diy.org>
> Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?
> 
> [CAUTION: Non-UBC Email]
> Dan,
> 
> I?ve been using the AS2164 only when I need the exponential response. If I need linear VCAs I now use the AS3364, which is more or less a clone of the SSM2024. That?s the same pinout more or less as the SSM2164 but has linear response. So, it?s very easy to use, pretrimmed, quiet, CV referenced to ground, summing node signal ins, doesn?t require all of those 560p caps. That works out great when lots of VCAs are needed, Some people were really turned off by the 1% harmonic distortion, but I have yet to notice an distortion on a synth circuit. 
> 
> https://www.alfarzpp.lv/eng/sc/AS3364.pdf
> 
> Mark
> 
> 
> 
> 
>> On Aug 8, 2024, at 8:08?PM, Dan Snazelle via Synth-diy <synth-diy at synth-diy.org> wrote:
>> 
>> imagine someone asked you to make some new synth modules.
>> then imagine that the last time you did so in any quantity above one---  it was 2017. 
>> 
>> 
>> I am trying to get a handle on what the parts landscape is like now for cost-effective CV control. Back in 2017 the lm13700 was really the only available OTA . I was just starting to work with the ssm2164 at the time but never used it extensively.
>> 
>> In the interim I have built synth circuits but only in quantities of one where cost was no object and I was able to rely on my own extensive parts supply. 
>> 
>> 
>> So my question is this-- if I am thinking about design for manufacturing?what do you think the best option is? 
>> 
>> Has anyone tried the quad ALFA OTA? Is it even readily available? Same for the new SSM2040?.  
>> 
>> OR would you just use the 2164 instead? 
>> OR would you just try to make discrete OTAS out of say the  BCM856DS //BCM847BS
>> 
>> thanks for any and all opinions on this. 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

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From electrocontinuo at gmail.com  Sat Aug 10 02:57:03 2024
From: electrocontinuo at gmail.com (Peter Pearson)
Date: Fri, 9 Aug 2024 20:57:03 -0400
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
Message-ID: <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>

I wish Alfa made clones of the Yamaha proprietary chips from the CS80 voice
board.  Can anyone talk to them about that?  I can't imagine it's a legal
issue if cloning CEM chips is fine, no?

On Fri, Aug 9, 2024 at 8:47?PM Chris McDowell via Synth-diy <
synth-diy at synth-diy.org> wrote:

> Alfa is usually pretty responsive to direct inquiries. I've bought a whole
> bunch of their 2164s.
>
> At least a year-ish ago, AS3364 was $2.90 @ 100, $1.85 > 1000
>
> Chris McDowell
>
> On Aug 9, 2024, at 11:31 AM, David G Dixon via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
> That sounds great.  My only issue is price -- The AS3364 seems to cost
> about $7 or more, depending on the source, and it does not seem to be
> possible to buy them directly from Alfa -- at least, I don't see any
> obvious way to do so from their website.
>
> My latest project is going to require about 250 2164 ICs.  That's not a
> problem given what I'm paying for them.  Yes, in all but the filter
> application, the 2164s are all linearized, but I'm paying about 23 cents
> for TL074s and about 1 cent for 561 caps, so from a cost perspective, it
> just doesn't make much sense.  Linearizing 2164 does add an inch or so to
> the PCB real estate, but I'm sending the same voltage to a large number
> (48) of 2164s, so even though they are linearized, only one logarithmic
> amplifier is needed for all of those 2164s.  I do need to buffer those CVs
> locally, so there is a TL074 sitting next to the 2164, but I would need to
> do that with the 3364 as well (the datasheet is silent on the input
> impedance of the control pins (big negative issue for me), but I presume
> that it is measured in kilo-ohms, not tera-ohms).  And, I'm getting four
> linearized amplifiers from each 2164 this way as well, rather than the
> customary two.
>
> I also (mostly now) use the 2164 as a four-quadrant (or variable-quadrant)
> multiplier, and it is not clear whether the 3364 is amenable to that
> application.
>
> If I could get the AS3364 for less than $2 each, then I'd probably get
> more serious about using them.
>
> ------------------------------
> *From:* Synth-diy [mailto:synth-diy-bounces at synth-diy.org
> <synth-diy-bounces at synth-diy.org>] *On Behalf Of *mark verbos via
> Synth-diy
> *Sent:* Friday, August 09, 2024 8:50 AM
> *To:* Dan Snazelle
> *Cc:* synth-diy at synth-diy.org
> *Subject:* Re: [sdiy] Best AVAILABLE OTA for building new designs?
>
> [*CAUTION:* Non-UBC Email]Dan,
>
> I?ve been using the AS2164 only when I need the exponential response. If I
> need linear VCAs I now use the AS3364, which is more or less a clone of the
> SSM2024. That?s the same pinout more or less as the SSM2164 but has linear
> response. So, it?s very easy to use, pretrimmed, quiet, CV referenced to
> ground, summing node signal ins, doesn?t require all of those 560p caps.
> That works out great when lots of VCAs are needed, Some people were really
> turned off by the 1% harmonic distortion, but I have yet to notice an
> distortion on a synth circuit.
>
> <preview.png>
>
> AS3364 <https://www.alfarzpp.lv/eng/sc/AS3364.pdf>
> PDF Document ? 494 KB <https://www.alfarzpp.lv/eng/sc/AS3364.pdf>
> <https://www.alfarzpp.lv/eng/sc/AS3364.pdf>
>
> Mark
>
>
>
>
> On Aug 8, 2024, at 8:08?PM, Dan Snazelle via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
> imagine someone asked you to make some new synth modules.
> then imagine that the last time you did so in any quantity above one---
> it was 2017.
>
>
> I am trying to get a handle on what the parts landscape is like now for
> cost-effective CV control. Back in 2017 the lm13700 was really the only
> available OTA . I was just starting to work with the ssm2164 at the time
> but never used it extensively.
>
> In the interim I have built synth circuits but only in quantities of one
> where cost was no object and I was able to rely on my own extensive parts
> supply.
>
>
> So my question is this-- if I am thinking about design for manufacturing?what
> do you think the best option is?
>
> Has anyone tried the quad ALFA OTA? Is it even readily available? Same for
> the new SSM2040?.
>
> OR would you just use the 2164 instead?
> OR would you just try to make discrete OTAS out of say the  BCM856DS
> //BCM847BS
>
> thanks for any and all opinions on this.
>
>
>
>
>
>
>
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From mbryant at futurehorizons.com  Sat Aug 10 04:36:10 2024
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Sat, 10 Aug 2024 02:36:10 +0000
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
Message-ID: <CWLP265MB7132CCDDF497085A421AFC34DBBB2@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

Yamaha has got FAR BIGGER lawyers :-)
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Peter Pearson via Synth-diy <synth-diy at synth-diy.org>
Sent: 10 August 2024 01:57
To: synth-diy mailing list <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?

I wish Alfa made clones of the Yamaha proprietary chips from the CS80 voice board.  Can anyone talk to them about that?  I can't imagine it's a legal issue if cloning CEM chips is fine, no?

On Fri, Aug 9, 2024 at 8:47?PM Chris McDowell via Synth-diy <synth-diy at synth-diy.org<mailto:synth-diy at synth-diy.org>> wrote:
Alfa is usually pretty responsive to direct inquiries. I've bought a whole bunch of their 2164s.

At least a year-ish ago, AS3364 was $2.90 @ 100, $1.85 > 1000

Chris McDowell
On Aug 9, 2024, at 11:31 AM, David G Dixon via Synth-diy <synth-diy at synth-diy.org<mailto:synth-diy at synth-diy.org>> wrote:

That sounds great.  My only issue is price -- The AS3364 seems to cost about $7 or more, depending on the source, and it does not seem to be possible to buy them directly from Alfa -- at least, I don't see any obvious way to do so from their website.

My latest project is going to require about 250 2164 ICs.  That's not a problem given what I'm paying for them.  Yes, in all but the filter application, the 2164s are all linearized, but I'm paying about 23 cents for TL074s and about 1 cent for 561 caps, so from a cost perspective, it just doesn't make much sense.  Linearizing 2164 does add an inch or so to the PCB real estate, but I'm sending the same voltage to a large number (48) of 2164s, so even though they are linearized, only one logarithmic amplifier is needed for all of those 2164s.  I do need to buffer those CVs locally, so there is a TL074 sitting next to the 2164, but I would need to do that with the 3364 as well (the datasheet is silent on the input impedance of the control pins (big negative issue for me), but I presume that it is measured in kilo-ohms, not tera-ohms).  And, I'm getting four linearized amplifiers from each 2164 this way as well, rather than the customary two.

I also (mostly now) use the 2164 as a four-quadrant (or variable-quadrant) multiplier, and it is not clear whether the 3364 is amenable to that application.

If I could get the AS3364 for less than $2 each, then I'd probably get more serious about using them.

________________________________
From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org] On Behalf Of mark verbos via Synth-diy
Sent: Friday, August 09, 2024 8:50 AM
To: Dan Snazelle
Cc: synth-diy at synth-diy.org<mailto:synth-diy at synth-diy.org>
Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?

[CAUTION: Non-UBC Email]
Dan,

I?ve been using the AS2164 only when I need the exponential response. If I need linear VCAs I now use the AS3364, which is more or less a clone of the SSM2024. That?s the same pinout more or less as the SSM2164 but has linear response. So, it?s very easy to use, pretrimmed, quiet, CV referenced to ground, summing node signal ins, doesn?t require all of those 560p caps. That works out great when lots of VCAs are needed, Some people were really turned off by the 1% harmonic distortion, but I have yet to notice an distortion on a synth circuit.

<https://www.alfarzpp.lv/eng/sc/AS3364.pdf>
<preview.png>
AS3364<https://www.alfarzpp.lv/eng/sc/AS3364.pdf>
PDF Document ? 494 KB<https://www.alfarzpp.lv/eng/sc/AS3364.pdf>

Mark




On Aug 8, 2024, at 8:08?PM, Dan Snazelle via Synth-diy <synth-diy at synth-diy.org<mailto:synth-diy at synth-diy.org>> wrote:

imagine someone asked you to make some new synth modules.
then imagine that the last time you did so in any quantity above one---  it was 2017.


I am trying to get a handle on what the parts landscape is like now for cost-effective CV control. Back in 2017 the lm13700 was really the only available OTA . I was just starting to work with the ssm2164 at the time but never used it extensively.

In the interim I have built synth circuits but only in quantities of one where cost was no object and I was able to rely on my own extensive parts supply.


So my question is this-- if I am thinking about design for manufacturing?what do you think the best option is?

Has anyone tried the quad ALFA OTA? Is it even readily available? Same for the new SSM2040?.

OR would you just use the 2164 instead?
OR would you just try to make discrete OTAS out of say the  BCM856DS //BCM847BS

thanks for any and all opinions on this.








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From tom at electricdruid.net  Sat Aug 10 10:13:30 2024
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sat, 10 Aug 2024 09:13:30 +0100
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
Message-ID: <9DADB490-2FF0-4780-A270-FCF592DEADF2@electricdruid.net>

I don't think it's a legal issue. Any patents that applied have expired by now, so there's nothing for lawyers to do. I think there are two problems:

1) Market size.
The CEM chips were used in a *lot* of synths, whereas the Yamaha chips were used only in very few.

2) Information
It's likely that Yamaha didn't provide full details of what they'd done in any patents they took out since copying their chips would have been pretty difficult for anyone smaller than they were back in the 1970's. The CEM technology is much better known.


> On 10 Aug 2024, at 01:57, Peter Pearson via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> I wish Alfa made clones of the Yamaha proprietary chips from the CS80 voice board.  Can anyone talk to them about that?  I can't imagine it's a legal issue if cloning CEM chips is fine, no?
> 
> On Fri, Aug 9, 2024 at 8:47?PM Chris McDowell via Synth-diy <synth-diy at synth-diy.org <mailto:synth-diy at synth-diy.org>> wrote:
> Alfa is usually pretty responsive to direct inquiries. I've bought a whole bunch of their 2164s. 
> 
> At least a year-ish ago, AS3364 was $2.90 @ 100, $1.85 > 1000
> 
> Chris McDowell 
>> On Aug 9, 2024, at 11:31 AM, David G Dixon via Synth-diy <synth-diy at synth-diy.org <mailto:synth-diy at synth-diy.org>> wrote:
>> 
>> That sounds great.  My only issue is price -- The AS3364 seems to cost about $7 or more, depending on the source, and it does not seem to be possible to buy them directly from Alfa -- at least, I don't see any obvious way to do so from their website.
>>  
>> My latest project is going to require about 250 2164 ICs.  That's not a problem given what I'm paying for them.  Yes, in all but the filter application, the 2164s are all linearized, but I'm paying about 23 cents for TL074s and about 1 cent for 561 caps, so from a cost perspective, it just doesn't make much sense.  Linearizing 2164 does add an inch or so to the PCB real estate, but I'm sending the same voltage to a large number (48) of 2164s, so even though they are linearized, only one logarithmic amplifier is needed for all of those 2164s.  I do need to buffer those CVs locally, so there is a TL074 sitting next to the 2164, but I would need to do that with the 3364 as well (the datasheet is silent on the input impedance of the control pins (big negative issue for me), but I presume that it is measured in kilo-ohms, not tera-ohms).  And, I'm getting four linearized amplifiers from each 2164 this way as well, rather than the customary two.
>>  
>> I also (mostly now) use the 2164 as a four-quadrant (or variable-quadrant) multiplier, and it is not clear whether the 3364 is amenable to that application.
>>  
>> If I could get the AS3364 for less than $2 each, then I'd probably get more serious about using them.
>> 
>> From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org <mailto:synth-diy-bounces at synth-diy.org>] On Behalf Of mark verbos via Synth-diy
>> Sent: Friday, August 09, 2024 8:50 AM
>> To: Dan Snazelle
>> Cc: synth-diy at synth-diy.org <mailto:synth-diy at synth-diy.org>
>> Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?
>> 
>> [CAUTION: Non-UBC Email]
>> Dan,
>> 
>> I?ve been using the AS2164 only when I need the exponential response. If I need linear VCAs I now use the AS3364, which is more or less a clone of the SSM2024. That?s the same pinout more or less as the SSM2164 but has linear response. So, it?s very easy to use, pretrimmed, quiet, CV referenced to ground, summing node signal ins, doesn?t require all of those 560p caps. That works out great when lots of VCAs are needed, Some people were really turned off by the 1% harmonic distortion, but I have yet to notice an distortion on a synth circuit. 
>> 
>> <preview.png>
>> AS3364
>> PDF Document ? 494 KB
>>  <https://www.alfarzpp.lv/eng/sc/AS3364.pdf>AS3364 <https://www.alfarzpp.lv/eng/sc/AS3364.pdf>
>> PDF Document ? 494 KB <https://www.alfarzpp.lv/eng/sc/AS3364.pdf>
>> 
>> Mark
>> 
>> 
>> 
>> 
>>> On Aug 8, 2024, at 8:08?PM, Dan Snazelle via Synth-diy <synth-diy at synth-diy.org <mailto:synth-diy at synth-diy.org>> wrote:
>>> 
>>> imagine someone asked you to make some new synth modules.
>>> then imagine that the last time you did so in any quantity above one---  it was 2017. 
>>> 
>>> 
>>> I am trying to get a handle on what the parts landscape is like now for cost-effective CV control. Back in 2017 the lm13700 was really the only available OTA . I was just starting to work with the ssm2164 at the time but never used it extensively.
>>> 
>>> In the interim I have built synth circuits but only in quantities of one where cost was no object and I was able to rely on my own extensive parts supply. 
>>> 
>>> 
>>> So my question is this-- if I am thinking about design for manufacturing?what do you think the best option is? 
>>> 
>>> Has anyone tried the quad ALFA OTA? Is it even readily available? Same for the new SSM2040?.  
>>> 
>>> OR would you just use the 2164 instead? 
>>> OR would you just try to make discrete OTAS out of say the  BCM856DS //BCM847BS
>>> 
>>> thanks for any and all opinions on this. 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> ________________________________________________________
>>> This is the Synth-diy mailing list
>>> Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
>>> View archive at: https://synth-diy.org/pipermail/synth-diy/ <https://synth-diy.org/pipermail/synth-diy/>
>>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy <https://synth-diy.org/mailman/listinfo/synth-diy>
>>> Selling or trading? Use marketplace at synth-diy.org <mailto:marketplace at synth-diy.org>
>> 
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
>> View archive at: https://synth-diy.org/pipermail/synth-diy/ <https://synth-diy.org/pipermail/synth-diy/>
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy <https://synth-diy.org/mailman/listinfo/synth-diy>
>> Selling or trading? Use marketplace at synth-diy.org <mailto:marketplace at synth-diy.org>
> ________________________________________________________
> This is the Synth-diy mailing list
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From mr at analogue.org  Sat Aug 10 14:45:07 2024
From: mr at analogue.org (Mattias Rickardsson)
Date: Sat, 10 Aug 2024 14:45:07 +0200
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
Message-ID: <CAP92RBX2+_n1=WPs-GbHTy8zFo_WU-F8QLKbb=RRm8rk90-DLA@mail.gmail.com>

Hi Dan,

Returning to the OP questions about today's OTAs, I'm curious to hear if
you specifically need OTAs and some of their properties (linear control,
differential inputs, voltage levels, current/voltage interfacing, etc), or
if VCAs would also be an alternative?

SSI2164 quad VCA is mentioned often since it's very easy and fun to design
with, but if I'd need a linear control I'd probably look for more
alternatives before I'd used the linearized 2164 method. It's not the
"best" VCA in terms of hi-fi quality, but it's very good - good enough for
synths and great price/performance compared to the hi-fi mixing console
ones. Also very handy to apply in designs, with a useful dB/V law, and with
a huge community knowledge base, which is another variant of "best".

Perhaps you're already skilled in OTA design and prefer continuing using
OTAs when it works, which is understandable. :-)

/mr  -  wouldn't be surprised if a new even better OTA chip saw the light
of day soon

Den tors 8 aug. 2024 20:14Dan Snazelle via Synth-diy <
synth-diy at synth-diy.org> skrev:

> imagine someone asked you to make some new synth modules.
> then imagine that the last time you did so in any quantity above one---
> it was 2017.
>
>
> I am trying to get a handle on what the parts landscape is like now for
> cost-effective CV control. Back in 2017 the lm13700 was really the only
> available OTA . I was just starting to work with the ssm2164 at the time
> but never used it extensively.
>
> In the interim I have built synth circuits but only in quantities of one
> where cost was no object and I was able to rely on my own extensive parts
> supply.
>
>
> So my question is this-- if I am thinking about design for manufacturing?what
> do you think the best option is?
>
> Has anyone tried the quad ALFA OTA? Is it even readily available? Same for
> the new SSM2040?.
>
> OR would you just use the 2164 instead?
> OR would you just try to make discrete OTAS out of say the  BCM856DS
> //BCM847BS
>
> thanks for any and all opinions on this.
>
>
>
>
>
>
>
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From list at mikebeauchamp.com  Sat Aug 10 20:48:51 2024
From: list at mikebeauchamp.com (Mike Beauchamp)
Date: Sat, 10 Aug 2024 14:48:51 -0400
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
Message-ID: <47ebbdd3-515b-45fc-8df0-0c62b475ec38@mikebeauchamp.com>



On 2024-08-09 12:31, David G Dixon via Synth-diy wrote:

> My latest project is going to require about 250 2164 ICs.? That's not a 
> problem given what I'm paying for them.? Yes, in all but the filter 
I don't think I'm the only person here interested in hearing more 
details about your project that uses 250 quad VCA's...

Mike

From ben at audio.computer  Sun Aug 11 10:35:37 2024
From: ben at audio.computer (Ben Walker)
Date: Sun, 11 Aug 2024 09:35:37 +0100
Subject: [sdiy] Arp Quartet ADSR issues
In-Reply-To: <CAKcdib34ZRLcpMo8S54-sSsi-qJftiTsqSMHD9WzuMuUR9N1EA@mail.gmail.com>
References: <CAKcdib34ZRLcpMo8S54-sSsi-qJftiTsqSMHD9WzuMuUR9N1EA@mail.gmail.com>
Message-ID: <3B9F13F3-FAA2-4AAB-8E32-5198819A80E6@audio.computer>

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From igg.debus at gmail.com  Sun Aug 11 11:50:00 2024
From: igg.debus at gmail.com (Ingo Debus)
Date: Sun, 11 Aug 2024 11:50:00 +0200
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <47ebbdd3-515b-45fc-8df0-0c62b475ec38@mikebeauchamp.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <47ebbdd3-515b-45fc-8df0-0c62b475ec38@mikebeauchamp.com>
Message-ID: <D72D1F31-AFAB-42A2-97A1-218B2CBA4424@gmail.com>



> Am 10.08.2024 um 20:48 schrieb Mike Beauchamp <list at mikebeauchamp.com>:
> 
>> My latest project is going to require about 250 2164 ICs.  That's not a problem given what I'm paying for them.  Yes, in all but the filter 
> I don't think I'm the only person here interested in hearing more details about your project that uses 250 quad VCA's?


A Hammond B3 style organ, where every key contact is replaced by a VCA? 2*61 keys, 9 contacts per key?

Any other ideas?

Ingo

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From gordonjcp at gjcp.net  Sun Aug 11 13:02:10 2024
From: gordonjcp at gjcp.net (Gordonjcp)
Date: Sun, 11 Aug 2024 12:02:10 +0100
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
Message-ID: <20240811110210.GA2509@gjcp.net>

On Fri, Aug 09, 2024 at 08:57:03PM -0400, Peter Pearson via Synth-diy wrote:
> I wish Alfa made clones of the Yamaha proprietary chips from the CS80 voice
> board.  Can anyone talk to them about that?  I can't imagine it's a legal
> issue if cloning CEM chips is fine, no?

Given that the Deckard's Dream exists, do we really need their custom chips?

Their filter ICs were just OTAs weren't they?

-- 
Gordonjcp


From ben.pi.bradley at gmail.com  Sun Aug 11 18:09:35 2024
From: ben.pi.bradley at gmail.com (Ben Bradley)
Date: Sun, 11 Aug 2024 12:09:35 -0400
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <20240811110210.GA2509@gjcp.net>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
 <20240811110210.GA2509@gjcp.net>
Message-ID: <CA+wjhVs22JT+7ut6fqgRc-8w5YOESABS0GSMkK4LJOaKpGjoMQ@mail.gmail.com>

I was thinking of the Roland chip (BA662A/BA662B) that hasn't been
mentioned, and I came across this discussion that may be helpful. For
high-quality "real VCAS" there's the chips from THATCorp, but they're
of course quite expensive compared to OTAs.

Regarding speculation of using a large quantity, a Hammond organ where
each harmonic has its own ADSR (with keyboard scaling and such) could
be interesting, though it would be cheaper to do in software.

https://www.reddit.com/r/synthdiy/comments/180u4it/vca_chips/

On Sun, 11 Aug 2024 at 07:05, Gordonjcp <gordonjcp at gjcp.net> wrote:
>
> On Fri, Aug 09, 2024 at 08:57:03PM -0400, Peter Pearson via Synth-diy wrote:
> > I wish Alfa made clones of the Yamaha proprietary chips from the CS80 voice
> > board.  Can anyone talk to them about that?  I can't imagine it's a legal
> > issue if cloning CEM chips is fine, no?
>
> Given that the Deckard's Dream exists, do we really need their custom chips?
>
> Their filter ICs were just OTAs weren't they?
>
> --
> Gordonjcp
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

From mr at analogue.org  Sun Aug 11 19:03:36 2024
From: mr at analogue.org (Mattias Rickardsson)
Date: Sun, 11 Aug 2024 19:03:36 +0200
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <D72D1F31-AFAB-42A2-97A1-218B2CBA4424@gmail.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <47ebbdd3-515b-45fc-8df0-0c62b475ec38@mikebeauchamp.com>
 <D72D1F31-AFAB-42A2-97A1-218B2CBA4424@gmail.com>
Message-ID: <CAP92RBXiD9jHXQjbneAQAMOMHoZXsRa7a97zC1rhpub0T0Mxhg@mail.gmail.com>

Ingo Debus via Synth-diy <synth-diy at synth-diy.org> skrev:

> Am 10.08.2024 um 20:48 schrieb Mike Beauchamp <list at mikebeauchamp.com>:
>
> My latest project is going to require about 250 2164 ICs.  That's not a
> problem given what I'm paying for them.  Yes, in all but the filter
>
> I don't think I'm the only person here interested in hearing more details
> about your project that uses 250 quad VCA's?
>
>
> A Hammond B3 style organ, where every key contact is replaced by a VCA?
> 2*61 keys, 9 contacts per key?
>
> Any other ideas?
>

A vocoder with all bands voltage-controllable? :-)

/mr

>
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From mbryant at futurehorizons.com  Sun Aug 11 21:12:52 2024
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Sun, 11 Aug 2024 19:12:52 +0000
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <CAP92RBXiD9jHXQjbneAQAMOMHoZXsRa7a97zC1rhpub0T0Mxhg@mail.gmail.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <47ebbdd3-515b-45fc-8df0-0c62b475ec38@mikebeauchamp.com>
 <D72D1F31-AFAB-42A2-97A1-218B2CBA4424@gmail.com>
 <CAP92RBXiD9jHXQjbneAQAMOMHoZXsRa7a97zC1rhpub0T0Mxhg@mail.gmail.com>
Message-ID: <CWLP265MB71323AB9855CC8C990C9ECBBDB842@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

It might just be a run of 250 modules with 1 per module :-)
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Mattias Rickardsson <mr at analogue.org>
Sent: 11 August 2024 18:03
To: Ingo Debus <igg.debus at gmail.com>
Cc: Synth DIY <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?

Ingo Debus via Synth-diy <synth-diy at synth-diy.org<mailto:synth-diy at synth-diy.org>> skrev:
Am 10.08.2024 um 20:48 schrieb Mike Beauchamp <list at mikebeauchamp.com<mailto:list at mikebeauchamp.com>>:

My latest project is going to require about 250 2164 ICs.  That's not a problem given what I'm paying for them.  Yes, in all but the filter
I don't think I'm the only person here interested in hearing more details about your project that uses 250 quad VCA's?

A Hammond B3 style organ, where every key contact is replaced by a VCA? 2*61 keys, 9 contacts per key?

Any other ideas?

A vocoder with all bands voltage-controllable? :-)

/mr
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From mr at analogue.org  Sun Aug 11 21:18:04 2024
From: mr at analogue.org (Mattias Rickardsson)
Date: Sun, 11 Aug 2024 21:18:04 +0200
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <CWLP265MB71323AB9855CC8C990C9ECBBDB842@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <47ebbdd3-515b-45fc-8df0-0c62b475ec38@mikebeauchamp.com>
 <D72D1F31-AFAB-42A2-97A1-218B2CBA4424@gmail.com>
 <CAP92RBXiD9jHXQjbneAQAMOMHoZXsRa7a97zC1rhpub0T0Mxhg@mail.gmail.com>
 <CWLP265MB71323AB9855CC8C990C9ECBBDB842@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <CAP92RBUwkmZzTAf5+vuMkHPFtB7Q79+OHh5A5b=CU9oZQF+p4g@mail.gmail.com>

Mike Bryant <mbryant at futurehorizons.com> skrev:

> It might just be a run of 250 modules with 1 per module :-)
>

Or even simpler - a run of 1000 modules with 1 VCA per module... ;-)

/mr

>
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From synth at schmitzbits.de  Sun Aug 11 22:06:18 2024
From: synth at schmitzbits.de (=?UTF-8?Q?Ren=C3=A9_Schmitz?=)
Date: Sun, 11 Aug 2024 22:06:18 +0200
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <CAP92RBUwkmZzTAf5+vuMkHPFtB7Q79+OHh5A5b=CU9oZQF+p4g@mail.gmail.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <47ebbdd3-515b-45fc-8df0-0c62b475ec38@mikebeauchamp.com>
 <D72D1F31-AFAB-42A2-97A1-218B2CBA4424@gmail.com>
 <CAP92RBXiD9jHXQjbneAQAMOMHoZXsRa7a97zC1rhpub0T0Mxhg@mail.gmail.com>
 <CWLP265MB71323AB9855CC8C990C9ECBBDB842@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAP92RBUwkmZzTAf5+vuMkHPFtB7Q79+OHh5A5b=CU9oZQF+p4g@mail.gmail.com>
Message-ID: <bc057623-f78c-4ad9-975c-c0219dbdcbfb@schmitzbits.de>

No, 4000 modules? that only need a one quadrant VCA. :)

Am 11.08.2024 um 21:18 schrieb Mattias Rickardsson:
> Mike Bryant <mbryant at futurehorizons.com> skrev:
>
>     It might just be a run of 250 modules with 1 per module :-)
>
>
> Or even simpler - a run of 1000 modules with 1 VCA per module... ;-)
>
> /mr
>
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to:Synth-diy at synth-diy.org
> View archive at:https://synth-diy.org/pipermail/synth-diy/
> Check your settings at:https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Usemarketplace at synth-diy.org

-- 
--
synth at schmitzbits.de
http://schmitzbits.de
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From mskala at northcoastsynthesis.com  Sun Aug 11 22:12:34 2024
From: mskala at northcoastsynthesis.com (mskala at northcoastsynthesis.com)
Date: Sun, 11 Aug 2024 16:12:34 -0400 (EDT)
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <CAP92RBUwkmZzTAf5+vuMkHPFtB7Q79+OHh5A5b=CU9oZQF+p4g@mail.gmail.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <47ebbdd3-515b-45fc-8df0-0c62b475ec38@mikebeauchamp.com>
 <D72D1F31-AFAB-42A2-97A1-218B2CBA4424@gmail.com>
 <CAP92RBXiD9jHXQjbneAQAMOMHoZXsRa7a97zC1rhpub0T0Mxhg@mail.gmail.com>
 <CWLP265MB71323AB9855CC8C990C9ECBBDB842@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAP92RBUwkmZzTAf5+vuMkHPFtB7Q79+OHh5A5b=CU9oZQF+p4g@mail.gmail.com>
Message-ID: <alpine.LNX.2.20.2408111612050.1788@kharasan.bonobo-conspiracy.ca>

On Sun, 11 Aug 2024, Mattias Rickardsson wrote:

> Mike Bryant <mbryant at futurehorizons.com> skrev:
>       It might just be a run of 250 modules with 1 per module :-)
>
>
> Or even simpler - a run of 1000 modules with 1 VCA per module... ;-)

It calls for some really annoying work with a razor blade.

-- 
Matthew Skala
North Coast Synthesis Ltd.

From dixon at mail.ubc.ca  Sun Aug 11 22:13:48 2024
From: dixon at mail.ubc.ca (David G Dixon)
Date: Sun, 11 Aug 2024 13:13:48 -0700
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <D72D1F31-AFAB-42A2-97A1-218B2CBA4424@gmail.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <47ebbdd3-515b-45fc-8df0-0c62b475ec38@mikebeauchamp.com>
 <D72D1F31-AFAB-42A2-97A1-218B2CBA4424@gmail.com>
Message-ID: <147ED6FDF37447B19C78B7E67B21951D@david78c70950b>

I'm actually building my own version of the Korg PS-3100.  I'm calling it
the Sketchy Labs DS-3100.  However, mine will have some unique features:
Saw, Tri, and (fully PWMable) Pulse waveforms will be blended with faders.
Also, HP, BP, and LP filter responses will be blended with faders.  Finally,
two complete and independent ADSR EGs per key (with hold functions), one for
the filter and one for the VCA, rather than just one.  Also, the filter ADSR
control will be bipolar for weird negative envelope effects.
 
Each ADSR requires one 2164, the filter and VCA together require one 2164,
and the waveform and filter response faders each require one 2164, per key.
That's five 2164s per key, times 48 keys, so there will be 240 2164s just on
the voicecards.  I'm presuming another 10 or so on the front panel controls
for a total of 250.  It may be slightly more or slightly less.
 
My worries with this beast are: 1) How much heat will the circuitry
generate?  I'm going to install a fan inside the case, but I don't know
whether it will be sufficient, particularly since many circuit boards will
be stacked about 1 cm apart.  2) Will a 3A+3A power supply be sufficient?
3) Will there be a problem mixing 48 key outputs together?  Will clipping be
a problem?  Obviously, all 48 keys will never be played at the same time,
but still.
 
This is a project that I have dreamed of doing ever since I started doing
synth DIY.  I know it's stupid and ill advised, but it has been a lot of fun
so far, and that's really the whole point.  It's going to take me months to
build, and that's also sort of the point.  I've designed the VCOs and the
voicecards, and built prototypes that I'm happy with, so once my huge 2164
order arrives, I'll start building.  I still have to design the circuitry
downsteam of the voicecards, and figure out the front panel, but I'm not too
worried about that.

  _____  

From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org] On Behalf Of Ingo
Debus via Synth-diy
Sent: Sunday, August 11, 2024 2:50 AM
To: Synth DIY
Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?


[CAUTION: Non-UBC Email]	



Am 10.08.2024 um 20:48 schrieb Mike Beauchamp <list at mikebeauchamp.com>:


My latest project is going to require about 250 2164 ICs.  That's not a
problem given what I'm paying for them.  Yes, in all but the filter 


I don't think I'm the only person here interested in hearing more details
about your project that uses 250 quad VCA's.


A Hammond B3 style organ, where every key contact is replaced by a VCA? 2*61
keys, 9 contacts per key? 

Any other ideas?

Ingo


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From mr at analogue.org  Sun Aug 11 23:13:45 2024
From: mr at analogue.org (Mattias Rickardsson)
Date: Sun, 11 Aug 2024 23:13:45 +0200
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <147ED6FDF37447B19C78B7E67B21951D@david78c70950b>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <47ebbdd3-515b-45fc-8df0-0c62b475ec38@mikebeauchamp.com>
 <D72D1F31-AFAB-42A2-97A1-218B2CBA4424@gmail.com>
 <147ED6FDF37447B19C78B7E67B21951D@david78c70950b>
Message-ID: <CAP92RBWEyinLup9tRzxSfTTah+XqLmGekNxNs2P76gMx+gLfug@mail.gmail.com>

On Sun, 11 Aug 2024 at 22:15, David G Dixon via Synth-diy <
synth-diy at synth-diy.org> wrote:

> I'm actually building my own version of the Korg PS-3100.  I'm calling it
> the Sketchy Labs DS-3100.
>

Hoo-haa!


> ...
> Each ADSR requires one 2164
>

Wouldn't one VCA per envelope generator be enough? Depends on the design,
of course.


> ...
> My worries with this beast are: 1) How much heat will the circuitry
> generate?
>

The majority of the power in a synth circuit is often burnt in the ICs just
by having them powered up, so try to estimate the number of them and their
supply voltage. Perhaps you use a lot of transistors instead, and perhaps
you use TL064 or other low-power op-amps - then things might be a bit
different and the above estimations less realistic.


>  I'm going to install a fan inside the case, but I don't know whether it
> will be sufficient, particularly since many circuit boards will be stacked
> about 1 cm apart.
>

Stack them vertically and also let air pass through the casing, and it will
be fine and cosy. :-)


> 3) Will there be a problem mixing 48 key outputs together?  Will clipping
> be a problem?  Obviously, all 48 keys will never be played at the same
> time, but still.
>

Gainstaging a synth with lots of voices is a nontrivial problem. But at
least it's just one gain factor that needs to be decided upon..


> This is a project that I have dreamed of doing ever since I started doing
> synth DIY.  I know it's stupid and ill advised, but it has been a lot of
> fun so far, and that's really the whole point.  It's going to take me
> months to build, and that's also sort of the point.  I've designed the VCOs
> and the voicecards, and built prototypes that I'm happy with, so once my
> huge 2164 order arrives, I'll start building.  I still have to design the
> circuitry downsteam of the voicecards, and figure out the front panel, but
> I'm not too worried about that.
>

Fun times! :-D

/mr
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From dixon at mail.ubc.ca  Sun Aug 11 23:30:48 2024
From: dixon at mail.ubc.ca (David G Dixon)
Date: Sun, 11 Aug 2024 14:30:48 -0700
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <CAP92RBWEyinLup9tRzxSfTTah+XqLmGekNxNs2P76gMx+gLfug@mail.gmail.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <47ebbdd3-515b-45fc-8df0-0c62b475ec38@mikebeauchamp.com>
 <D72D1F31-AFAB-42A2-97A1-218B2CBA4424@gmail.com>
 <147ED6FDF37447B19C78B7E67B21951D@david78c70950b>
 <CAP92RBWEyinLup9tRzxSfTTah+XqLmGekNxNs2P76gMx+gLfug@mail.gmail.com>
Message-ID: <5C39CEBCB4C4406C9BCF9F2E4DE93A0D@david78c70950b>

 >>  Each ADSR requires one 2164

 >  Wouldn't one VCA per envelope generator be enough? Depends on the
design, of course.
 
No, because all of the controls must be voltage controlled.  I tried
switching the A, D and R voltages to a single VCA, but it was not practical.
What I ended up doing was using separate VCAs for A, D and R.  The control
voltages from the front panel are locally buffered and sent through three
channels of a 4066 analog switch.  When each switch is off, the voltage at
that VCA's control pin is pulled up to about +5V by a 10k resistor to the
15V rail.  This effectively turns that VCA off.  All three VCAs are in the
feedback loop of the EG integrator (remember, 2164 VCAs must terminate to
virtual ground).  Believe me, I tried many different ways to do this, and
this was the only way that worked perfectly.  The fourth VCA of the 2164 is
a linearized VCA (the log amp is on the front panel) which controls the
amount of the envelope being sent to its destination.
 
>> Will there be a problem mixing 48 key outputs together?  Will clipping be
a problem?  Obviously, all 48 keys will never be played at the same time,
but still.

 >  Gainstaging a synth with lots of voices is a nontrivial problem. But at
least it's just one gain factor that needs to be decided upon..
 
I may have to come back here for some advice when I get to the point of
adding all of the voices together.  Right now, I'm just thinking of summing
them all at unity gain at a single opamp (i.e., 48 10k resistors into the
inverting input, and a 10k feedback resistor).  Maybe I'll have to make sure
that the voicecard outputs are suitably attenuated so that I can add many of
them together without fear of clipping.  This is something about which I
haven't given much thought yet.  How does an electronic organ manage this
problem?
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From cfo at synthcube.com  Mon Aug 12 06:50:28 2024
From: cfo at synthcube.com (Chris H. Park)
Date: Mon, 12 Aug 2024 04:50:28 +0000
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <147ED6FDF37447B19C78B7E67B21951D@david78c70950b>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <47ebbdd3-515b-45fc-8df0-0c62b475ec38@mikebeauchamp.com>
 <D72D1F31-AFAB-42A2-97A1-218B2CBA4424@gmail.com>
 <147ED6FDF37447B19C78B7E67B21951D@david78c70950b>
Message-ID: <6A94AE2B-9FC4-4F89-919B-34734170FB4B@synthcube.com>

Nice! Exciting!

Sent from my iPhone

On Aug 12, 2024, at 5:24?AM, David G Dixon via Synth-diy <synth-diy at synth-diy.org> wrote:

?
I'm actually building my own version of the Korg PS-3100.  I'm calling it the Sketchy Labs DS-3100.  However, mine will have some unique features: Saw, Tri, and (fully PWMable) Pulse waveforms will be blended with faders.  Also, HP, BP, and LP filter responses will be blended with faders.  Finally, two complete and independent ADSR EGs per key (with hold functions), one for the filter and one for the VCA, rather than just one.  Also, the filter ADSR control will be bipolar for weird negative envelope effects.

Each ADSR requires one 2164, the filter and VCA together require one 2164, and the waveform and filter response faders each require one 2164, per key.  That's five 2164s per key, times 48 keys, so there will be 240 2164s just on the voicecards.  I'm presuming another 10 or so on the front panel controls for a total of 250.  It may be slightly more or slightly less.

My worries with this beast are: 1) How much heat will the circuitry generate?  I'm going to install a fan inside the case, but I don't know whether it will be sufficient, particularly since many circuit boards will be stacked about 1 cm apart.  2) Will a 3A+3A power supply be sufficient?  3) Will there be a problem mixing 48 key outputs together?  Will clipping be a problem?  Obviously, all 48 keys will never be played at the same time, but still.

This is a project that I have dreamed of doing ever since I started doing synth DIY.  I know it's stupid and ill advised, but it has been a lot of fun so far, and that's really the whole point.  It's going to take me months to build, and that's also sort of the point.  I've designed the VCOs and the voicecards, and built prototypes that I'm happy with, so once my huge 2164 order arrives, I'll start building.  I still have to design the circuitry downsteam of the voicecards, and figure out the front panel, but I'm not too worried about that.

________________________________
From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org] On Behalf Of Ingo Debus via Synth-diy
Sent: Sunday, August 11, 2024 2:50 AM
To: Synth DIY
Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?

[CAUTION: Non-UBC Email]


Am 10.08.2024 um 20:48 schrieb Mike Beauchamp <list at mikebeauchamp.com<mailto:list at mikebeauchamp.com>>:

My latest project is going to require about 250 2164 ICs.  That's not a problem given what I'm paying for them.  Yes, in all but the filter
I don't think I'm the only person here interested in hearing more details about your project that uses 250 quad VCA's?

A Hammond B3 style organ, where every key contact is replaced by a VCA? 2*61 keys, 9 contacts per key?

Any other ideas?

Ingo

________________________________________________________
This is the Synth-diy mailing list
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From gordonjcp at gjcp.net  Mon Aug 12 10:13:21 2024
From: gordonjcp at gjcp.net (Gordonjcp)
Date: Mon, 12 Aug 2024 09:13:21 +0100
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <CA+wjhVs22JT+7ut6fqgRc-8w5YOESABS0GSMkK4LJOaKpGjoMQ@mail.gmail.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
 <20240811110210.GA2509@gjcp.net>
 <CA+wjhVs22JT+7ut6fqgRc-8w5YOESABS0GSMkK4LJOaKpGjoMQ@mail.gmail.com>
Message-ID: <20240812081321.GA21657@gjcp.net>

On Sun, Aug 11, 2024 at 12:09:35PM -0400, Ben Bradley via Synth-diy wrote:
> I was thinking of the Roland chip (BA662A/BA662B) that hasn't been
> mentioned, and I came across this discussion that may be helpful. For
> high-quality "real VCAS" there's the chips from THATCorp, but they're
> of course quite expensive compared to OTAs.

If anyone can tell the difference between a BA662 and an LM13700 VCA in an honest double-blind test, I'll buy them the best Juno 6 I can find.

After they test clean for cocaine.

-- 
Gordonjcp


From mbryant at futurehorizons.com  Mon Aug 12 10:41:38 2024
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Mon, 12 Aug 2024 08:41:38 +0000
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <20240812081321.GA21657@gjcp.net>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
 <20240811110210.GA2509@gjcp.net>
 <CA+wjhVs22JT+7ut6fqgRc-8w5YOESABS0GSMkK4LJOaKpGjoMQ@mail.gmail.com>
 <20240812081321.GA21657@gjcp.net>
Message-ID: <CWLP265MB7132BD2046DCB5DAA6E8A496DB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

Except for noise floor in a mic amp with the gain wound up to maximum where there might be a very slight difference, I'll do the same for a 5532 and any of these fancy op-amps :-)

Of course there are op-amps which do sound different - the ones with added distortion.  Maybe the BA662 also adds something that way ?
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Gordonjcp <gordonjcp at gjcp.net>
Sent: 12 August 2024 09:13
To: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?

On Sun, Aug 11, 2024 at 12:09:35PM -0400, Ben Bradley via Synth-diy wrote:
> I was thinking of the Roland chip (BA662A/BA662B) that hasn't been
> mentioned, and I came across this discussion that may be helpful. For
> high-quality "real VCAS" there's the chips from THATCorp, but they're
> of course quite expensive compared to OTAs.

If anyone can tell the difference between a BA662 and an LM13700 VCA in an honest double-blind test, I'll buy them the best Juno 6 I can find.

After they test clean for cocaine.

--
Gordonjcp

________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
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From jacobwatters at gmail.com  Mon Aug 12 15:26:33 2024
From: jacobwatters at gmail.com (Jacob Watters)
Date: Mon, 12 Aug 2024 09:26:33 -0400
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <CWLP265MB7132BD2046DCB5DAA6E8A496DB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
 <20240811110210.GA2509@gjcp.net>
 <CA+wjhVs22JT+7ut6fqgRc-8w5YOESABS0GSMkK4LJOaKpGjoMQ@mail.gmail.com>
 <20240812081321.GA21657@gjcp.net>
 <CWLP265MB7132BD2046DCB5DAA6E8A496DB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <CAKcdib3h=KQbEd4_OFo6LVkBunABet+Dk1Ub9eaQtNo0zhkCKg@mail.gmail.com>

"3) Will there be a problem mixing 48 key outputs together?  Will clipping
be a problem?  Obviously, all 48 keys will never be played at the same
time, but still."

What I did for a top octave synth that I made is I added gain control to
the mixer. Then I could turn it up when playing mono or low polyphony, and
turn it down when playing dual chords like an organ.

Another option is to aim for a max note count. The max notes likely to be
played at once is probably around 8. Maybe plan for that, and adjust
accordingly.

*Jacob Watters*
JacobWatters.com <http://jacobwatters.com/>


On Mon, Aug 12, 2024 at 4:45?AM Mike Bryant <mbryant at futurehorizons.com>
wrote:

> Except for noise floor in a mic amp with the gain wound up to maximum
> where there might be a very slight difference, I'll do the same for a 5532
> and any of these fancy op-amps :-)
>
> Of course there are op-amps which do sound different - the ones with added
> distortion.  Maybe the BA662 also adds something that way ?
> ------------------------------
> *From:* Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of
> Gordonjcp <gordonjcp at gjcp.net>
> *Sent:* 12 August 2024 09:13
> *To:* synth-diy at synth-diy.org <synth-diy at synth-diy.org>
> *Subject:* Re: [sdiy] Best AVAILABLE OTA for building new designs?
>
> On Sun, Aug 11, 2024 at 12:09:35PM -0400, Ben Bradley via Synth-diy wrote:
> > I was thinking of the Roland chip (BA662A/BA662B) that hasn't been
> > mentioned, and I came across this discussion that may be helpful. For
> > high-quality "real VCAS" there's the chips from THATCorp, but they're
> > of course quite expensive compared to OTAs.
>
> If anyone can tell the difference between a BA662 and an LM13700 VCA in an
> honest double-blind test, I'll buy them the best Juno 6 I can find.
>
> After they test clean for cocaine.
>
> --
> Gordonjcp
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
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From mbryant at futurehorizons.com  Mon Aug 12 15:38:16 2024
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Mon, 12 Aug 2024 13:38:16 +0000
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <CAKcdib3h=KQbEd4_OFo6LVkBunABet+Dk1Ub9eaQtNo0zhkCKg@mail.gmail.com>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
 <20240811110210.GA2509@gjcp.net>
 <CA+wjhVs22JT+7ut6fqgRc-8w5YOESABS0GSMkK4LJOaKpGjoMQ@mail.gmail.com>
 <20240812081321.GA21657@gjcp.net>
 <CWLP265MB7132BD2046DCB5DAA6E8A496DB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAKcdib3h=KQbEd4_OFo6LVkBunABet+Dk1Ub9eaQtNo0zhkCKg@mail.gmail.com>
Message-ID: <CWLP265MB713252EC8F600902DE397EDBDB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

I think you need to watch some videos of the late Keith Emerson.  He'd happily have twenty or more keys pressed on a Hammond, some of course held down with knives :-)

As for the mixing, this is a problem met on all modular analogue mixers where running the virtual earth of the summing node the whole length of the console is the weak point for noise injection.  Fortunately for the OP, he can probably mix signals for each octave locally using an op-amp adder, then sum all of these in a second stage of addition.

It might be worth (digitally) monitoring how many keys are pressed and reducing the gain by some sort of curve above a certain number of keys pressed.
________________________________
From: Jacob Watters <jacobwatters at gmail.com>
Sent: 12 August 2024 14:26
To: Mike Bryant <mbryant at futurehorizons.com>
Cc: Gordonjcp <gordonjcp at gjcp.net>; synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?

"3) Will there be a problem mixing 48 key outputs together?  Will clipping be a problem?  Obviously, all 48 keys will never be played at the same time, but still."

What I did for a top octave synth that I made is I added gain control to the mixer. Then I could turn it up when playing mono or low polyphony, and turn it down when playing dual chords like an organ.

Another option is to aim for a max note count. The max notes likely to be played at once is probably around 8. Maybe plan for that, and adjust accordingly.

Jacob Watters
JacobWatters.com<http://jacobwatters.com/>


On Mon, Aug 12, 2024 at 4:45?AM Mike Bryant <mbryant at futurehorizons.com<mailto:mbryant at futurehorizons.com>> wrote:
Except for noise floor in a mic amp with the gain wound up to maximum where there might be a very slight difference, I'll do the same for a 5532 and any of these fancy op-amps :-)

Of course there are op-amps which do sound different - the ones with added distortion.  Maybe the BA662 also adds something that way ?
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org<mailto:synth-diy-bounces at synth-diy.org>> on behalf of Gordonjcp <gordonjcp at gjcp.net<mailto:gordonjcp at gjcp.net>>
Sent: 12 August 2024 09:13
To: synth-diy at synth-diy.org<mailto:synth-diy at synth-diy.org> <synth-diy at synth-diy.org<mailto:synth-diy at synth-diy.org>>
Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?

On Sun, Aug 11, 2024 at 12:09:35PM -0400, Ben Bradley via Synth-diy wrote:
> I was thinking of the Roland chip (BA662A/BA662B) that hasn't been
> mentioned, and I came across this discussion that may be helpful. For
> high-quality "real VCAS" there's the chips from THATCorp, but they're
> of course quite expensive compared to OTAs.

If anyone can tell the difference between a BA662 and an LM13700 VCA in an honest double-blind test, I'll buy them the best Juno 6 I can find.

After they test clean for cocaine.

--
Gordonjcp

________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org<mailto:Synth-diy at synth-diy.org>
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From tom at electricdruid.net  Mon Aug 12 15:56:58 2024
From: tom at electricdruid.net (Tom Wiltshire)
Date: Mon, 12 Aug 2024 14:56:58 +0100
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <CWLP265MB713252EC8F600902DE397EDBDB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
 <20240811110210.GA2509@gjcp.net>
 <CA+wjhVs22JT+7ut6fqgRc-8w5YOESABS0GSMkK4LJOaKpGjoMQ@mail.gmail.com>
 <20240812081321.GA21657@gjcp.net>
 <CWLP265MB7132BD2046DCB5DAA6E8A496DB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAKcdib3h=KQbEd4_OFo6LVkBunABet+Dk1Ub9eaQtNo0zhkCKg@mail.gmail.com>
 <CWLP265MB713252EC8F600902DE397EDBDB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <8BC4ADF2-34F1-49B9-9078-590364EFD503@electricdruid.net>



> On 12 Aug 2024, at 14:38, Mike Bryant <mbryant at futurehorizons.com> wrote:
> 
> It might be worth (digitally) monitoring how many keys are pressed and reducing the gain by some sort of curve above a certain number of keys pressed.

Somehow I doubt that's what Korg did!!

I think you just pick a number of how many notes you want to play with the guarantee of no distortion, and then design for that. Even adding more notes into the area where they could theoretically create distortion it won't necessarily happen since waveform peaks rarely line up, or if they do, it's only very briefly. You generally get a fair bit of leeway beyond the worst case scenario.

Tom

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From synthdiy at adambaby.com  Mon Aug 12 23:54:24 2024
From: synthdiy at adambaby.com (Adam (synthDIY))
Date: Tue, 13 Aug 2024 07:54:24 +1000
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <CWLP265MB713252EC8F600902DE397EDBDB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <PH7PR12MB7188F3E61394055ED5CFA40BC8B92@PH7PR12MB7188.namprd12.prod.outlook.com>
 <5F3F7E5A-E878-4667-8CDD-5837C820AA09@gmail.com>
 <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
 <20240811110210.GA2509@gjcp.net>
 <CA+wjhVs22JT+7ut6fqgRc-8w5YOESABS0GSMkK4LJOaKpGjoMQ@mail.gmail.com>
 <20240812081321.GA21657@gjcp.net>
 <CWLP265MB7132BD2046DCB5DAA6E8A496DB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAKcdib3h=KQbEd4_OFo6LVkBunABet+Dk1Ub9eaQtNo0zhkCKg@mail.gmail.com>
 <CWLP265MB713252EC8F600902DE397EDBDB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <BBDA54C7-0A12-4759-9226-017AC9E5FDDE@adambaby.com>



> On 12 Aug 2024, at 11:38?PM, Mike Bryant <mbryant at futurehorizons.com> wrote:
> 
> I think you need to watch some videos of the late Keith Emerson.  He'd happily have twenty or more keys pressed on a Hammond, some of course held down with knives :-)

David, you might be able to use this as a "feature"...  have a front panel control labelled "Knife Factor" that switches in a compressor with auto-make-up gain... 

erm
I'll get my coat...

A
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From gordonjcp at gjcp.net  Tue Aug 13 08:47:30 2024
From: gordonjcp at gjcp.net (Gordonjcp)
Date: Tue, 13 Aug 2024 07:47:30 +0100
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <BBDA54C7-0A12-4759-9226-017AC9E5FDDE@adambaby.com>
References: <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
 <20240811110210.GA2509@gjcp.net>
 <CA+wjhVs22JT+7ut6fqgRc-8w5YOESABS0GSMkK4LJOaKpGjoMQ@mail.gmail.com>
 <20240812081321.GA21657@gjcp.net>
 <CWLP265MB7132BD2046DCB5DAA6E8A496DB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAKcdib3h=KQbEd4_OFo6LVkBunABet+Dk1Ub9eaQtNo0zhkCKg@mail.gmail.com>
 <CWLP265MB713252EC8F600902DE397EDBDB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <BBDA54C7-0A12-4759-9226-017AC9E5FDDE@adambaby.com>
Message-ID: <20240813064730.GA27812@gjcp.net>

On Tue, Aug 13, 2024 at 07:54:24AM +1000, Adam (synthDIY) wrote:
> 
> 
> > On 12 Aug 2024, at 11:38?PM, Mike Bryant <mbryant at futurehorizons.com> wrote:
> > 
> > I think you need to watch some videos of the late Keith Emerson.  He'd happily have twenty or more keys pressed on a Hammond, some of course held down with knives :-)
> 
> David, you might be able to use this as a "feature"...  have a front panel control labelled "Knife Factor" that switches in a compressor with auto-make-up gain... 

Given that compressors work by controlling their gain based on output level - a negative feedback loop - I have this feeling that you could probably sum all the VCA CVs to give a "total output demand" voltage, which could be fed back to the DAC Vref (taking us back around to the multiplying DAC question) to depress the output voltage and keep the total level approximately constant.

"Approximately" because you'd want it to have a bit of dynamics, you wouldn't want one note to be as loud as ten, but maybe five should be as loud as ten.

-- 
Gordonjcp


From mr at analogue.org  Tue Aug 13 11:06:34 2024
From: mr at analogue.org (Mattias Rickardsson)
Date: Tue, 13 Aug 2024 11:06:34 +0200
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <20240813064730.GA27812@gjcp.net>
References: <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
 <20240811110210.GA2509@gjcp.net>
 <CA+wjhVs22JT+7ut6fqgRc-8w5YOESABS0GSMkK4LJOaKpGjoMQ@mail.gmail.com>
 <20240812081321.GA21657@gjcp.net>
 <CWLP265MB7132BD2046DCB5DAA6E8A496DB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAKcdib3h=KQbEd4_OFo6LVkBunABet+Dk1Ub9eaQtNo0zhkCKg@mail.gmail.com>
 <CWLP265MB713252EC8F600902DE397EDBDB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <BBDA54C7-0A12-4759-9226-017AC9E5FDDE@adambaby.com>
 <20240813064730.GA27812@gjcp.net>
Message-ID: <CAP92RBV6YaWVyQ1331sfE+ttSayUCVc7RVBJExDAge4irY10uA@mail.gmail.com>

Sounds like we are starting to overdesign things a bit here... :-D
Btw the "counting notes and keeping total volume constant" idea reminds me
of one of the Unison modes in Roland Jupiter-4, where you depending on the
number of depressed keys get 4-voice unison, 2x 2-voice unison, 3-voice
poly or 4-voice poly. The level loss in this mode is remarkable and not
very nice, especially when playing a 3-note chord and getting only 3 voices
playing compared to playing 1 note and getting 4 voces playing.

Anyway, I don't think the all-polyphonic voice summing issue should be too
over-thought, but just try to combine
- a summing where everything fits without clipping
- a level control that can gain even more so that clipping could occur but
a melody player would have enough output level.

One of the trickiest bits is that resonant filters make peak levels vary a
LOT more than you first might think, so you'll have to count with a peak
voice level that is much higher than many typical sounds.

Hopefully this is less of a problem in a true PS3100 voice where resonances
are very moderate. In the gainstaging of polysynth designs in general,
there is a huge advantage if you manage to keep filter resonances limited -
everything level related gets easier, but on the other hand it's hard to
make a firm resonance limiter without adding unwanted distortion or side
effects to the filter sound.

/mr

On Tue, 13 Aug 2024 at 08:49, Gordonjcp <gordonjcp at gjcp.net> wrote:

> On Tue, Aug 13, 2024 at 07:54:24AM +1000, Adam (synthDIY) wrote:
> >
> >
> > > On 12 Aug 2024, at 11:38?PM, Mike Bryant <mbryant at futurehorizons.com>
> wrote:
> > >
> > > I think you need to watch some videos of the late Keith Emerson.  He'd
> happily have twenty or more keys pressed on a Hammond, some of course held
> down with knives :-)
> >
> > David, you might be able to use this as a "feature"...  have a front
> panel control labelled "Knife Factor" that switches in a compressor with
> auto-make-up gain...
>
> Given that compressors work by controlling their gain based on output
> level - a negative feedback loop - I have this feeling that you could
> probably sum all the VCA CVs to give a "total output demand" voltage, which
> could be fed back to the DAC Vref (taking us back around to the multiplying
> DAC question) to depress the output voltage and keep the total level
> approximately constant.
>
> "Approximately" because you'd want it to have a bit of dynamics, you
> wouldn't want one note to be as loud as ten, but maybe five should be as
> loud as ten.
>
> --
> Gordonjcp
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From synthdiy at adambaby.com  Tue Aug 13 11:34:16 2024
From: synthdiy at adambaby.com (Adam (synthDIY))
Date: Tue, 13 Aug 2024 19:34:16 +1000
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <CAP92RBV6YaWVyQ1331sfE+ttSayUCVc7RVBJExDAge4irY10uA@mail.gmail.com>
References: <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
 <20240811110210.GA2509@gjcp.net>
 <CA+wjhVs22JT+7ut6fqgRc-8w5YOESABS0GSMkK4LJOaKpGjoMQ@mail.gmail.com>
 <20240812081321.GA21657@gjcp.net>
 <CWLP265MB7132BD2046DCB5DAA6E8A496DB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAKcdib3h=KQbEd4_OFo6LVkBunABet+Dk1Ub9eaQtNo0zhkCKg@mail.gmail.com>
 <CWLP265MB713252EC8F600902DE397EDBDB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <BBDA54C7-0A12-4759-9226-017AC9E5FDDE@adambaby.com>
 <20240813064730.GA27812@gjcp.net>
 <CAP92RBV6YaWVyQ1331sfE+ttSayUCVc7RVBJExDAge4irY10uA@mail.gmail.com>
Message-ID: <9D4AA180-7313-401A-9E7B-A0439ED5EBF2@adambaby.com>



> On 13 Aug 2024, at 7:06?PM, Mattias Rickardsson <mr at analogue.org> wrote:
> 
> Sounds like we are starting to overdesign things a bit here... :-D
> Btw the "counting notes and keeping total volume constant" idea reminds me of one of the Unison modes in Roland Jupiter-4, where you depending on the number of depressed keys get 4-voice unison, 2x 2-voice unison, 3-voice poly or 4-voice poly. The level loss in this mode is remarkable and not very nice, especially when playing a 3-note chord and getting only 3 voices playing compared to playing 1 note and getting 4 voces playing.

That's interesting. (That doesn't seem to be an issue with JP8 unison - making it a very useful option in many cases for sounds that are not simply pads, yet not quite "lead" sounds either. One note will employ a massive 16 oscillators, two notes - eight oscillators, etc and the transition seems quite smooth)


> Anyway, I don't think the all-polyphonic voice summing issue should be too over-thought, but just try to combine 
> - a summing where everything fits without clipping
> - a level control that can gain even more so that clipping could occur but a melody player would have enough output level.

Many old-school electric instruments "suffered" from an apparent slight volume drop ("sag") the more notes that were played - the reasons being many and varied. 
It happens in my 1968 Farfisa Compact and I ::think:: it has to do with the twin triode tube (pre-amp and reverb tank driver) circuit, but I'm not certain. It certainly adds character and musicality.


> 
> One of the trickiest bits is that resonant filters make peak levels vary a LOT more than you first might think, so you'll have to count with a peak voice level that is much higher than many typical sounds. 
> 
> Hopefully this is less of a problem in a true PS3100 voice where resonances are very moderate. In the gainstaging of polysynth designs in general, there is a huge advantage if you manage to keep filter resonances limited - everything level related gets easier, but on the other hand it's hard to make a firm resonance limiter without adding unwanted distortion or side effects to the filter sound.
> 
> /mr
> 
> On Tue, 13 Aug 2024 at 08:49, Gordonjcp <gordonjcp at gjcp.net <mailto:gordonjcp at gjcp.net>> wrote:
>> On Tue, Aug 13, 2024 at 07:54:24AM +1000, Adam (synthDIY) wrote:
>> > 
>> > 
>> > > On 12 Aug 2024, at 11:38?PM, Mike Bryant <mbryant at futurehorizons.com <mailto:mbryant at futurehorizons.com>> wrote:
>> > > 
>> > > I think you need to watch some videos of the late Keith Emerson.  He'd happily have twenty or more keys pressed on a Hammond, some of course held down with knives :-)
>> > 
>> > David, you might be able to use this as a "feature"...  have a front panel control labelled "Knife Factor" that switches in a compressor with auto-make-up gain... 
>> 
>> Given that compressors work by controlling their gain based on output level - a negative feedback loop - I have this feeling that you could probably sum all the VCA CVs to give a "total output demand" voltage, which could be fed back to the DAC Vref (taking us back around to the multiplying DAC question) to depress the output voltage and keep the total level approximately constant.
>> 
>> "Approximately" because you'd want it to have a bit of dynamics, you wouldn't want one note to be as loud as ten, but maybe five should be as loud as ten.
>> 
>> -- 
>> Gordonjcp
>> 
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org <mailto:marketplace at synth-diy.org>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

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From mbryant at futurehorizons.com  Tue Aug 13 11:38:15 2024
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Tue, 13 Aug 2024 09:38:15 +0000
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <CAP92RBV6YaWVyQ1331sfE+ttSayUCVc7RVBJExDAge4irY10uA@mail.gmail.com>
References: <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
 <20240811110210.GA2509@gjcp.net>
 <CA+wjhVs22JT+7ut6fqgRc-8w5YOESABS0GSMkK4LJOaKpGjoMQ@mail.gmail.com>
 <20240812081321.GA21657@gjcp.net>
 <CWLP265MB7132BD2046DCB5DAA6E8A496DB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAKcdib3h=KQbEd4_OFo6LVkBunABet+Dk1Ub9eaQtNo0zhkCKg@mail.gmail.com>
 <CWLP265MB713252EC8F600902DE397EDBDB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <BBDA54C7-0A12-4759-9226-017AC9E5FDDE@adambaby.com>
 <20240813064730.GA27812@gjcp.net>
 <CAP92RBV6YaWVyQ1331sfE+ttSayUCVc7RVBJExDAge4irY10uA@mail.gmail.com>
Message-ID: <CWLP265MB7132C2FD9FFE55996FEDA4A4DB862@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

The overload problem is one reason to go software.  Lots of algorithms available for setting the starting phases of each tone so that you are unlikely to overload the output.  Though avoid Schroeder-phase harmonic tone complexes which have an absolutely level envelope as the sound suddenly changes to a rising chirp.
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Mattias Rickardsson <mr at analogue.org>
Sent: 13 August 2024 10:06
To: Gordonjcp <gordonjcp at gjcp.net>
Cc: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?

Sounds like we are starting to overdesign things a bit here... :-D
Btw the "counting notes and keeping total volume constant" idea reminds me of one of the Unison modes in Roland Jupiter-4, where you depending on the number of depressed keys get 4-voice unison, 2x 2-voice unison, 3-voice poly or 4-voice poly. The level loss in this mode is remarkable and not very nice, especially when playing a 3-note chord and getting only 3 voices playing compared to playing 1 note and getting 4 voces playing.

Anyway, I don't think the all-polyphonic voice summing issue should be too over-thought, but just try to combine
- a summing where everything fits without clipping
- a level control that can gain even more so that clipping could occur but a melody player would have enough output level.

One of the trickiest bits is that resonant filters make peak levels vary a LOT more than you first might think, so you'll have to count with a peak voice level that is much higher than many typical sounds.

Hopefully this is less of a problem in a true PS3100 voice where resonances are very moderate. In the gainstaging of polysynth designs in general, there is a huge advantage if you manage to keep filter resonances limited - everything level related gets easier, but on the other hand it's hard to make a firm resonance limiter without adding unwanted distortion or side effects to the filter sound.

/mr

On Tue, 13 Aug 2024 at 08:49, Gordonjcp <gordonjcp at gjcp.net<mailto:gordonjcp at gjcp.net>> wrote:
On Tue, Aug 13, 2024 at 07:54:24AM +1000, Adam (synthDIY) wrote:
>
>
> > On 12 Aug 2024, at 11:38?PM, Mike Bryant <mbryant at futurehorizons.com<mailto:mbryant at futurehorizons.com>> wrote:
> >
> > I think you need to watch some videos of the late Keith Emerson.  He'd happily have twenty or more keys pressed on a Hammond, some of course held down with knives :-)
>
> David, you might be able to use this as a "feature"...  have a front panel control labelled "Knife Factor" that switches in a compressor with auto-make-up gain...

Given that compressors work by controlling their gain based on output level - a negative feedback loop - I have this feeling that you could probably sum all the VCA CVs to give a "total output demand" voltage, which could be fed back to the DAC Vref (taking us back around to the multiplying DAC question) to depress the output voltage and keep the total level approximately constant.

"Approximately" because you'd want it to have a bit of dynamics, you wouldn't want one note to be as loud as ten, but maybe five should be as loud as ten.

--
Gordonjcp

________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org<mailto:Synth-diy at synth-diy.org>
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From mr at analogue.org  Tue Aug 13 12:00:06 2024
From: mr at analogue.org (Mattias Rickardsson)
Date: Tue, 13 Aug 2024 12:00:06 +0200
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <FD8BF308-EAAE-47B2-A66D-09AB72220E85@adambaby.com>
References: <CAP92RBVYJ53ShuQLCjf3AnY4Q=PJwtwBwT1k5t5ZpB3BdXZPLg@mail.gmail.com>
 <CA+owdPs5QVDEL49pVzAd85XNxVwOyM-824uwEHRh0EiueEr-1A@mail.gmail.com>
 <CA+owdPvRxDzf223ePSxWXpmB1QQT7ES9UHettOMjqerWyPC5Rg@mail.gmail.com>
 <CA+owdPvE5rmee7TMhJ7RFF+=JwWtbjuc7g4oBzHtoLWFH49uHA@mail.gmail.com>
 <CA+owdPsnetpv5fMdFaA6yAcLVFD9_ckg8=Vi607SycV6smrCZQ@mail.gmail.com>
 <CAP92RBVZMrw3a6mG5Aan=nY2ZmkDwzPZVK2n21-7ajBD4T7OkA@mail.gmail.com>
 <FD8BF308-EAAE-47B2-A66D-09AB72220E85@adambaby.com>
Message-ID: <CAP92RBW+0SA3th_2P-dx1zPfHyJq_=VB0W18Wp9dxoH5r6gi6Q@mail.gmail.com>

What would Alvin Lucier have done with a sampler with tape dump feature? ;-)

("I am sitting in a room" -> "I am sampling in a dump"...)

/mr


On Thu, 8 Aug 2024 at 09:46, Adam (synthDIY) <synthdiy at adambaby.com> wrote:

>
>
> On 8 Aug 2024, at 5:04?PM, Mattias Rickardsson <mr at analogue.org> wrote:
>
>  The tape dump method is of course much "better" since it's lossless, and
> also might have needed less expensive/messy hardware solutions back in the
> day.
>
>
>
> Ha ha exactly!
> "Makes sense on paper" doesn't it...
> but the "lossy" use of these things just adds to their character,
> musically, of course
>
> (e.g. the S612 has this fabulous function they call "Overdub" where you
> can record a new sample over the previous one... ad infinitum.. with the
> sampler making adjustments to the gain each time to compensate... )
>
> A
>
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From ulfurh at gmail.com  Tue Aug 13 15:56:13 2024
From: ulfurh at gmail.com (ulfur hansson)
Date: Tue, 13 Aug 2024 13:56:13 +0000
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CAP92RBW+0SA3th_2P-dx1zPfHyJq_=VB0W18Wp9dxoH5r6gi6Q@mail.gmail.com>
References: <CAP92RBW+0SA3th_2P-dx1zPfHyJq_=VB0W18Wp9dxoH5r6gi6Q@mail.gmail.com>
Message-ID: <8081D489-AB95-479E-B90C-E72624E94343@gmail.com>

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From dixon at mail.ubc.ca  Tue Aug 13 21:20:42 2024
From: dixon at mail.ubc.ca (David G Dixon)
Date: Tue, 13 Aug 2024 12:20:42 -0700
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <20240813064730.GA27812@gjcp.net>
References: <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
 <20240811110210.GA2509@gjcp.net>
 <CA+wjhVs22JT+7ut6fqgRc-8w5YOESABS0GSMkK4LJOaKpGjoMQ@mail.gmail.com>
 <20240812081321.GA21657@gjcp.net>
 <CWLP265MB7132BD2046DCB5DAA6E8A496DB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAKcdib3h=KQbEd4_OFo6LVkBunABet+Dk1Ub9eaQtNo0zhkCKg@mail.gmail.com>
 <CWLP265MB713252EC8F600902DE397EDBDB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <BBDA54C7-0A12-4759-9226-017AC9E5FDDE@adambaby.com>
 <20240813064730.GA27812@gjcp.net>
Message-ID: <CDA6C5A90B0D4104A94E5FCF143C3701@david78c70950b>

I have actually implemented something similar on my "Delta Quadrant" dual multiplier module -- a "Limiter" circuit that keeps the output to maximum 10Vpp regardless of the position of the "Quadrant" control.  For 10Vpp input signals, 2-quadrant multiplication results in an output amplitude of about 16Vpp, whereas 4-quadrant multiplication gives about 10Vpp.  With linearized 2164s it is easy to do this sort of thing, but I'm not quite sure how to do it with 48 independent VCAs taking control voltages from 48 independent ADSRs.

I think what I might do instead is implement some sort of accounting technique that counts up how many keys are depressed (active gates), and adjusts all of the VCAs accordingly based on some sort of logic.  I can simply sum a negative "adjustment" voltage into all of the VCAs in parallel.  The amount of adjustment can even be put under panel control.  I'll have to think about this a little bit.  It would have to be pretty subtle so as not to have sudden changes in loudness when keys are released.


-----Original Message-----
From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org] On Behalf Of Gordonjcp
Sent: Monday, August 12, 2024 11:48 PM
To: synth-diy at synth-diy.org
Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?

[CAUTION: Non-UBC Email]

On Tue, Aug 13, 2024 at 07:54:24AM +1000, Adam (synthDIY) wrote:
> 
> 
> > On 12 Aug 2024, at 11:38?PM, Mike Bryant <mbryant at futurehorizons.com> wrote:
> > 
> > I think you need to watch some videos of the late Keith Emerson.  He'd happily have twenty or more keys pressed on a Hammond, some of course held down with knives :-)
> 
> David, you might be able to use this as a "feature"...  have a front panel control labelled "Knife Factor" that switches in a compressor with auto-make-up gain... 

Given that compressors work by controlling their gain based on output level - a negative feedback loop - I have this feeling that you could probably sum all the VCA CVs to give a "total output demand" voltage, which could be fed back to the DAC Vref (taking us back around to the multiplying DAC question) to depress the output voltage and keep the total level approximately constant.

"Approximately" because you'd want it to have a bit of dynamics, you wouldn't want one note to be as loud as ten, but maybe five should be as loud as ten.

-- 
Gordonjcp

________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
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From dixon at mail.ubc.ca  Tue Aug 13 21:27:23 2024
From: dixon at mail.ubc.ca (David G Dixon)
Date: Tue, 13 Aug 2024 12:27:23 -0700
Subject: [sdiy] FW:  Best AVAILABLE OTA for building new designs?
Message-ID: <CD3805529C114190BDD6D8337BC1E53C@david78c70950b>

Digital.  Ugh.  I only build analog synthesizers because it's fun.  Coding isn't fun (for me).  I know that computer chips can do anything, and that's why they hold absolutely zero charm for me.

  _____  

From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org] On Behalf Of Mike Bryant
Sent: Tuesday, August 13, 2024 2:38 AM
To: Mattias Rickardsson; Gordonjcp
Cc: synth-diy at synth-diy.org
Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?


[CAUTION: Non-UBC Email]	
The overload problem is one reason to go software.  Lots of algorithms available for setting the starting phases of each tone so that you are unlikely to overload the output.  Though avoid Schroeder-phase harmonic tone complexes which have an absolutely level envelope as the sound suddenly changes to a rising chirp.
  _____  

From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Mattias Rickardsson <mr at analogue.org>
Sent: 13 August 2024 10:06
To: Gordonjcp <gordonjcp at gjcp.net>
Cc: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs? 
 
Sounds like we are starting to overdesign things a bit here... :-D 
Btw the "counting notes and keeping total volume constant" idea reminds me of one of the Unison modes in Roland Jupiter-4, where you depending on the number of depressed keys get 4-voice unison, 2x 2-voice unison, 3-voice poly or 4-voice poly. The level loss in this mode is remarkable and not very nice, especially when playing a 3-note chord and getting only 3 voices playing compared to playing 1 note and getting 4 voces playing.

Anyway, I don't think the all-polyphonic voice summing issue should be too over-thought, but just try to combine 
- a summing where everything fits without clipping
- a level control that can gain even more so that clipping could occur but a melody player would have enough output level.

One of the trickiest bits is that resonant filters make peak levels vary a LOT more than you first might think, so you'll have to count with a peak voice level that is much higher than many typical sounds. 

Hopefully this is less of a problem in a true PS3100 voice where resonances are very moderate. In the gainstaging of polysynth designs in general, there is a huge advantage if you manage to keep filter resonances limited - everything level related gets easier, but on the other hand it's hard to make a firm resonance limiter without adding unwanted distortion or side effects to the filter sound.

/mr

On Tue, 13 Aug 2024 at 08:49, Gordonjcp <gordonjcp at gjcp.net> wrote:


On Tue, Aug 13, 2024 at 07:54:24AM +1000, Adam (synthDIY) wrote:
> 
> 
> > On 12 Aug 2024, at 11:38?PM, Mike Bryant <mbryant at futurehorizons.com> wrote:
> > 
> > I think you need to watch some videos of the late Keith Emerson.  He'd happily have twenty or more keys pressed on a Hammond, some of course held down with knives :-)
> 
> David, you might be able to use this as a "feature"...  have a front panel control labelled "Knife Factor" that switches in a compressor with auto-make-up gain... 

Given that compressors work by controlling their gain based on output level - a negative feedback loop - I have this feeling that you could probably sum all the VCA CVs to give a "total output demand" voltage, which could be fed back to the DAC Vref (taking us back around to the multiplying DAC question) to depress the output voltage and keep the total level approximately constant.

"Approximately" because you'd want it to have a bit of dynamics, you wouldn't want one note to be as loud as ten, but maybe five should be as loud as ten.

-- 
Gordonjcp

________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
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From mr at analogue.org  Tue Aug 13 21:37:40 2024
From: mr at analogue.org (Mattias Rickardsson)
Date: Tue, 13 Aug 2024 21:37:40 +0200
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <8081D489-AB95-479E-B90C-E72624E94343@gmail.com>
References: <CAP92RBW+0SA3th_2P-dx1zPfHyJq_=VB0W18Wp9dxoH5r6gi6Q@mail.gmail.com>
 <8081D489-AB95-479E-B90C-E72624E94343@gmail.com>
Message-ID: <CAP92RBUd_ZNt5DzFzF+3Uu2q9Fm9PZug75znNQZFKpi62=Xx+A@mail.gmail.com>

Sounds like an awesome extrapolation of Lucier's masterpiece! :-)

Another nice one is this:
https://repeatle.bandcamp.com/album/wf1-2023
by Wind & Fire (Andreas Tilliander & Christian Hutchinson-Berg),
a cassette release in limited edition of 100 copies (literally).

"Each cassette is a duplicate of the previous one where cassette number 001
is the master, 002 a copy of 001, 003 of 002, 004 of 003 et cetera.
In this way, every cassette is unique and the sound is slowly degrading,
getting more distorted and weird with each new copy.
A nod to Alvin Lucier?s I Am Sitting In a Room or perhaps even more to the
The Cure cassettes we taped from and to our friends as kids. The cover art
is treated the same way."

Here's a picture of some of the cassette covers, number 1, 11, and 36:
https://www.facebook.com/share/p/MZX3i67G3euGvrs9/

Quite refreshing concept art after all. Interesting twist that each
cassette owner gets only one slice of the degradation, not the full
degradation process like in Alvin Lucier's "I am sitting in a room".

Hmm, makes me wonder what number of generations my old cassette copy of J-M
Jarre's "Music for Supermarkets" is... Speaking of saving samples onto
tape. 8-)

/mr

Den tis 13 aug. 2024 15:56ulfur hansson <ulfurh at gmail.com> skrev:

> Haha! Thats a great question - reminds me of the youtube version of I am
> sitting in a room - some guy uploaded/downloaded a video of himself
> reciting the text 1000x times and it gradually turns into a pastel coloured
> smear with very ambient sounding skype-ish soundscapes ?
>
> sent from outer space
>
> On 13 Aug 2024, at 10:03, Mattias Rickardsson <mr at analogue.org> wrote:
>
> ?
> What would Alvin Lucier have done with a sampler with tape dump feature?
> ;-)
>
> ("I am sitting in a room" -> "I am sampling in a dump"...)
>
> /mr
>
>
> On Thu, 8 Aug 2024 at 09:46, Adam (synthDIY) <synthdiy at adambaby.com>
> wrote:
>
>>
>>
>> On 8 Aug 2024, at 5:04?PM, Mattias Rickardsson <mr at analogue.org> wrote:
>>
>>  The tape dump method is of course much "better" since it's lossless,
>> and also might have needed less expensive/messy hardware solutions back in
>> the day.
>>
>>
>>
>> Ha ha exactly!
>> "Makes sense on paper" doesn't it...
>> but the "lossy" use of these things just adds to their character,
>> musically, of course
>>
>> (e.g. the S612 has this fabulous function they call "Overdub" where you
>> can record a new sample over the previous one... ad infinitum.. with the
>> sampler making adjustments to the gain each time to compensate... )
>>
>> A
>>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
>
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From sines_list at scale.la  Tue Aug 13 22:37:11 2024
From: sines_list at scale.la (Todd Sines)
Date: Tue, 13 Aug 2024 16:37:11 -0400
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CAP92RBUd_ZNt5DzFzF+3Uu2q9Fm9PZug75znNQZFKpi62=Xx+A@mail.gmail.com>
References: <CAP92RBUd_ZNt5DzFzF+3Uu2q9Fm9PZug75znNQZFKpi62=Xx+A@mail.gmail.com>
Message-ID: <A466E4BA-F660-4953-A96C-9D2FA2103BA8@scale.la>

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From neil.johnson71 at gmail.com  Wed Aug 14 13:52:47 2024
From: neil.johnson71 at gmail.com (Neil Johnson)
Date: Wed, 14 Aug 2024 12:52:47 +0100
Subject: [sdiy] Cambridge weekend reminder
Message-ID: <CACZGMxJe0H_waXa00Tn+ArDdW_Qo=nDDLZCZEv3jmBn64Yt1PA@mail.gmail.com>

Hi all,

Quick reminder for this year?s Synth DIY Cambridge weekend 27-29th
September at Robinson College. Room bookings close 10th September so book
early to avoid disappointment!

www.synth-diy.uk

Cheers
Neil
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From rainer at buchty.net  Wed Aug 14 19:00:36 2024
From: rainer at buchty.net (Rainer Buchty)
Date: Wed, 14 Aug 2024 19:00:36 +0200 (CEST)
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <CAP92RBUd_ZNt5DzFzF+3Uu2q9Fm9PZug75znNQZFKpi62=Xx+A@mail.gmail.com>
References: <CAP92RBW+0SA3th_2P-dx1zPfHyJq_=VB0W18Wp9dxoH5r6gi6Q@mail.gmail.com>
 <8081D489-AB95-479E-B90C-E72624E94343@gmail.com>
 <CAP92RBUd_ZNt5DzFzF+3Uu2q9Fm9PZug75znNQZFKpi62=Xx+A@mail.gmail.com>
Message-ID: <e96ed010-fe9e-dc67-7a32-d8b6fbf2f816@buchty.net>

On Tue, 13 Aug 2024, Mattias Rickardsson wrote:

> Hmm, makes me wonder what number of generations my old cassette copy 
> of J-M Jarre's "Music for Supermarkets" is...

You can get a "clean" copy here :)

 	https://www.youtube.com/watch?v=pVIblDQqTcw

I wonder whether part #6 did resurface anywhere?

Rainer

From rburnett at richieburnett.co.uk  Wed Aug 14 19:42:28 2024
From: rburnett at richieburnett.co.uk (rburnett at richieburnett.co.uk)
Date: Wed, 14 Aug 2024 18:42:28 +0100
Subject: [sdiy] Mystery synth sound
Message-ID: <dac8de1c3cb7fc43f2f046285d3b03b9@richieburnett.co.uk>

Hi synth fans,

I'd like to pick your brains about how a particular synth sound was 
created...  I've always liked this sound that features on a number of 
Jam and Spoon tracks (Rolf Ellmer & Markus Loffel) from the 90's and 
early 2000's.  It sounds like a resonant lowpass filter sweep but there 
is something else to it, and I've never heard anything quite like it 
anywhere else.  The resonance seems to have a dirty and distinctly harsh 
"scratchy" sound to it which I think works nicely in the genre they used 
it in.  It appears all over their album "Tripomatic Fairyfales 2001" 
like it's their trademark sound!  I'd love to know what piece of kit is 
used to produce this sound if anyone knows?

I'm guessing it might be the result of filter FM or some kind of 
overdriven digital filter, but I've never managed to get anything like 
this out of any of my filters, digital or analogue.  Or maybe it's some 
post processing like decimation, although it doesn't sound quite like 
aliasing to my ears either.

The best example I've found is at the start of "Follow Me":

https://www.youtube.com/watch?v=UfR7o8NI2W0
The synth starts at 0:00 and is initially quite smooth and clean 
sounding while the filter is closed down, but gets really scratchy from 
0:30 onwards as the filter opens up.

There are other examples in "Tripomatic Fairytales 2001" too:
https://www.youtube.com/watch?v=vvf4wwDpaCw
The synth starts at 17:35 but getting scratchy from 18:20 throughout 
that song.
The synth starts on another track at 49:00 but getting scratchy from 
49:10 onwards to the end of that song.

Any ideas?  This has been bugging me for about 20 years, so I'm all 
ears! ;-))

-Richie,


From elmacaco at hotmail.com  Wed Aug 14 19:44:12 2024
From: elmacaco at hotmail.com (el macaco)
Date: Wed, 14 Aug 2024 17:44:12 +0000
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <CWLP265MB7132C2FD9FFE55996FEDA4A4DB862@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
 <20240811110210.GA2509@gjcp.net>
 <CA+wjhVs22JT+7ut6fqgRc-8w5YOESABS0GSMkK4LJOaKpGjoMQ@mail.gmail.com>
 <20240812081321.GA21657@gjcp.net>
 <CWLP265MB7132BD2046DCB5DAA6E8A496DB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAKcdib3h=KQbEd4_OFo6LVkBunABet+Dk1Ub9eaQtNo0zhkCKg@mail.gmail.com>
 <CWLP265MB713252EC8F600902DE397EDBDB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <BBDA54C7-0A12-4759-9226-017AC9E5FDDE@adambaby.com>
 <20240813064730.GA27812@gjcp.net>
 <CAP92RBV6YaWVyQ1331sfE+ttSayUCVc7RVBJExDAge4irY10uA@mail.gmail.com>
 <CWLP265MB7132C2FD9FFE55996FEDA4A4DB862@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <BY3PR19MB51404ECA9DEDC0DECEB305B4C4862@BY3PR19MB5140.namprd19.prod.outlook.com>

The Alesis Andromeda has a mod source of a voltage that increases with the number of voices.

I think in the tips and tricks document they mention this to reduce clipping in popy patches with loud monosynth like voices.

Es

Get Outlook for iOS<https://aka.ms/o0ukef>
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Mike Bryant <mbryant at futurehorizons.com>
Sent: Tuesday, August 13, 2024 4:38:15 AM
To: Mattias Rickardsson <mr at analogue.org>; Gordonjcp <gordonjcp at gjcp.net>
Cc: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?

The overload problem is one reason to go software.  Lots of algorithms available for setting the starting phases of each tone so that you are unlikely to overload the output.  Though avoid Schroeder-phase harmonic tone complexes which have an absolutely level envelope as the sound suddenly changes to a rising chirp.
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Mattias Rickardsson <mr at analogue.org>
Sent: 13 August 2024 10:06
To: Gordonjcp <gordonjcp at gjcp.net>
Cc: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?

Sounds like we are starting to overdesign things a bit here... :-D
Btw the "counting notes and keeping total volume constant" idea reminds me of one of the Unison modes in Roland Jupiter-4, where you depending on the number of depressed keys get 4-voice unison, 2x 2-voice unison, 3-voice poly or 4-voice poly. The level loss in this mode is remarkable and not very nice, especially when playing a 3-note chord and getting only 3 voices playing compared to playing 1 note and getting 4 voces playing.

Anyway, I don't think the all-polyphonic voice summing issue should be too over-thought, but just try to combine
- a summing where everything fits without clipping
- a level control that can gain even more so that clipping could occur but a melody player would have enough output level.

One of the trickiest bits is that resonant filters make peak levels vary a LOT more than you first might think, so you'll have to count with a peak voice level that is much higher than many typical sounds.

Hopefully this is less of a problem in a true PS3100 voice where resonances are very moderate. In the gainstaging of polysynth designs in general, there is a huge advantage if you manage to keep filter resonances limited - everything level related gets easier, but on the other hand it's hard to make a firm resonance limiter without adding unwanted distortion or side effects to the filter sound.

/mr

On Tue, 13 Aug 2024 at 08:49, Gordonjcp <gordonjcp at gjcp.net<mailto:gordonjcp at gjcp.net>> wrote:
On Tue, Aug 13, 2024 at 07:54:24AM +1000, Adam (synthDIY) wrote:
>
>
> > On 12 Aug 2024, at 11:38?PM, Mike Bryant <mbryant at futurehorizons.com<mailto:mbryant at futurehorizons.com>> wrote:
> >
> > I think you need to watch some videos of the late Keith Emerson.  He'd happily have twenty or more keys pressed on a Hammond, some of course held down with knives :-)
>
> David, you might be able to use this as a "feature"...  have a front panel control labelled "Knife Factor" that switches in a compressor with auto-make-up gain...

Given that compressors work by controlling their gain based on output level - a negative feedback loop - I have this feeling that you could probably sum all the VCA CVs to give a "total output demand" voltage, which could be fed back to the DAC Vref (taking us back around to the multiplying DAC question) to depress the output voltage and keep the total level approximately constant.

"Approximately" because you'd want it to have a bit of dynamics, you wouldn't want one note to be as loud as ten, but maybe five should be as loud as ten.

--
Gordonjcp

________________________________________________________
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From jacobwatters at gmail.com  Wed Aug 14 19:56:00 2024
From: jacobwatters at gmail.com (Jacob Watters)
Date: Wed, 14 Aug 2024 13:56:00 -0400
Subject: [sdiy] Mystery synth sound
In-Reply-To: <dac8de1c3cb7fc43f2f046285d3b03b9@richieburnett.co.uk>
References: <dac8de1c3cb7fc43f2f046285d3b03b9@richieburnett.co.uk>
Message-ID: <CAKcdib0xnKRWb3LW6QtGcDKfA-PWhmA1gbqAn1WuO65AqhEpgg@mail.gmail.com>

That sounds like a bit crusher to me. Have you tried that?

*Jacob Watters*
JacobWatters.com <http://jacobwatters.com/>


On Wed, Aug 14, 2024 at 1:45?PM <rburnett at richieburnett.co.uk> wrote:

> Hi synth fans,
>
> I'd like to pick your brains about how a particular synth sound was
> created...  I've always liked this sound that features on a number of
> Jam and Spoon tracks (Rolf Ellmer & Markus Loffel) from the 90's and
> early 2000's.  It sounds like a resonant lowpass filter sweep but there
> is something else to it, and I've never heard anything quite like it
> anywhere else.  The resonance seems to have a dirty and distinctly harsh
> "scratchy" sound to it which I think works nicely in the genre they used
> it in.  It appears all over their album "Tripomatic Fairyfales 2001"
> like it's their trademark sound!  I'd love to know what piece of kit is
> used to produce this sound if anyone knows?
>
> I'm guessing it might be the result of filter FM or some kind of
> overdriven digital filter, but I've never managed to get anything like
> this out of any of my filters, digital or analogue.  Or maybe it's some
> post processing like decimation, although it doesn't sound quite like
> aliasing to my ears either.
>
> The best example I've found is at the start of "Follow Me":
>
> https://www.youtube.com/watch?v=UfR7o8NI2W0
> The synth starts at 0:00 and is initially quite smooth and clean
> sounding while the filter is closed down, but gets really scratchy from
> 0:30 onwards as the filter opens up.
>
> There are other examples in "Tripomatic Fairytales 2001" too:
> https://www.youtube.com/watch?v=vvf4wwDpaCw
> The synth starts at 17:35 but getting scratchy from 18:20 throughout
> that song.
> The synth starts on another track at 49:00 but getting scratchy from
> 49:10 onwards to the end of that song.
>
> Any ideas?  This has been bugging me for about 20 years, so I'm all
> ears! ;-))
>
> -Richie,
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From tpuefke at protonmail.com  Wed Aug 14 20:31:40 2024
From: tpuefke at protonmail.com (tpuefke)
Date: Wed, 14 Aug 2024 18:31:40 +0000
Subject: [sdiy] Mystery synth sound
In-Reply-To: <dac8de1c3cb7fc43f2f046285d3b03b9@richieburnett.co.uk>
References: <dac8de1c3cb7fc43f2f046285d3b03b9@richieburnett.co.uk>
Message-ID: <2Hx3d9SgpS9UPD89NGub5KM56BzpL1CTliCvd90opIVb19nEbVLkwTnzvbgZjmX59EnxtezLvXfaU4oUO85expPpjE1_3S1vBrmpcexPLlM=@protonmail.com>

Hi Richie,

I believe I'm hearing high frequency modulation of (assuming) a bandpass filter, likely from a noise or audio source in the first example. The additional effect sounds very much like sample rate reduction indeed. Perhaps using an analog sample and hold at (comparatively) low clock speed, because it sounds very gritty. But could just as well be some kind of old school digital lo-fi effect, not sure.

In the second example I would say the filter modulation sounds a lot more regular, like from a faster LFO. Not hearing the aliasing-type effect like in the first one.

I would say both synth sounds are using at least two oscillators, and I have a feeling that square or pulse waves are involved. 

This is much fun. Very interested to hear people's suggestions.

Cheers,
Tom


On Wednesday, August 14th, 2024 at 19:42, rburnett at richieburnett.co.uk <rburnett at richieburnett.co.uk> wrote:

> 
> 
> Hi synth fans,
> 
> I'd like to pick your brains about how a particular synth sound was
> created... I've always liked this sound that features on a number of
> Jam and Spoon tracks (Rolf Ellmer & Markus Loffel) from the 90's and
> early 2000's. It sounds like a resonant lowpass filter sweep but there
> is something else to it, and I've never heard anything quite like it
> anywhere else. The resonance seems to have a dirty and distinctly harsh
> "scratchy" sound to it which I think works nicely in the genre they used
> it in. It appears all over their album "Tripomatic Fairyfales 2001"
> like it's their trademark sound! I'd love to know what piece of kit is
> used to produce this sound if anyone knows?
> 
> I'm guessing it might be the result of filter FM or some kind of
> overdriven digital filter, but I've never managed to get anything like
> this out of any of my filters, digital or analogue. Or maybe it's some
> post processing like decimation, although it doesn't sound quite like
> aliasing to my ears either.
> 
> The best example I've found is at the start of "Follow Me":
> 
> https://www.youtube.com/watch?v=UfR7o8NI2W0
> The synth starts at 0:00 and is initially quite smooth and clean
> sounding while the filter is closed down, but gets really scratchy from
> 0:30 onwards as the filter opens up.
> 
> There are other examples in "Tripomatic Fairytales 2001" too:
> https://www.youtube.com/watch?v=vvf4wwDpaCw
> The synth starts at 17:35 but getting scratchy from 18:20 throughout
> that song.
> The synth starts on another track at 49:00 but getting scratchy from
> 49:10 onwards to the end of that song.
> 
> Any ideas? This has been bugging me for about 20 years, so I'm all
> ears! ;-))
> 
> -Richie,
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org


From mr at analogue.org  Wed Aug 14 20:36:19 2024
From: mr at analogue.org (Mattias Rickardsson)
Date: Wed, 14 Aug 2024 20:36:19 +0200
Subject: [sdiy] Mystery synth sound
In-Reply-To: <CAKcdib0xnKRWb3LW6QtGcDKfA-PWhmA1gbqAn1WuO65AqhEpgg@mail.gmail.com>
References: <dac8de1c3cb7fc43f2f046285d3b03b9@richieburnett.co.uk>
 <CAKcdib0xnKRWb3LW6QtGcDKfA-PWhmA1gbqAn1WuO65AqhEpgg@mail.gmail.com>
Message-ID: <CAP92RBWhTfaoNN9eFStc3PyYtTmXpr0SneS0a6H=EdT-hxsPvQ@mail.gmail.com>

Sounds like audio-rate filter FM to me.
Did they use an Akai AX-60? :-)

/mr

Den ons 14 aug. 2024 19:58Jacob Watters via Synth-diy <
synth-diy at synth-diy.org> skrev:

> That sounds like a bit crusher to me. Have you tried that?
>
> *Jacob Watters*
> JacobWatters.com <http://jacobwatters.com/>
>
>
> On Wed, Aug 14, 2024 at 1:45?PM <rburnett at richieburnett.co.uk> wrote:
>
>> Hi synth fans,
>>
>> I'd like to pick your brains about how a particular synth sound was
>> created...  I've always liked this sound that features on a number of
>> Jam and Spoon tracks (Rolf Ellmer & Markus Loffel) from the 90's and
>> early 2000's.  It sounds like a resonant lowpass filter sweep but there
>> is something else to it, and I've never heard anything quite like it
>> anywhere else.  The resonance seems to have a dirty and distinctly harsh
>> "scratchy" sound to it which I think works nicely in the genre they used
>> it in.  It appears all over their album "Tripomatic Fairyfales 2001"
>> like it's their trademark sound!  I'd love to know what piece of kit is
>> used to produce this sound if anyone knows?
>>
>> I'm guessing it might be the result of filter FM or some kind of
>> overdriven digital filter, but I've never managed to get anything like
>> this out of any of my filters, digital or analogue.  Or maybe it's some
>> post processing like decimation, although it doesn't sound quite like
>> aliasing to my ears either.
>>
>> The best example I've found is at the start of "Follow Me":
>>
>> https://www.youtube.com/watch?v=UfR7o8NI2W0
>> The synth starts at 0:00 and is initially quite smooth and clean
>> sounding while the filter is closed down, but gets really scratchy from
>> 0:30 onwards as the filter opens up.
>>
>> There are other examples in "Tripomatic Fairytales 2001" too:
>> https://www.youtube.com/watch?v=vvf4wwDpaCw
>> The synth starts at 17:35 but getting scratchy from 18:20 throughout
>> that song.
>> The synth starts on another track at 49:00 but getting scratchy from
>> 49:10 onwards to the end of that song.
>>
>> Any ideas?  This has been bugging me for about 20 years, so I'm all
>> ears! ;-))
>>
>> -Richie,
>>
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
>>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From sines_list at scale.la  Wed Aug 14 20:49:57 2024
From: sines_list at scale.la (Todd Sines)
Date: Wed, 14 Aug 2024 14:49:57 -0400
Subject: [sdiy] Mystery synth sound
In-Reply-To: <2Hx3d9SgpS9UPD89NGub5KM56BzpL1CTliCvd90opIVb19nEbVLkwTnzvbgZjmX59EnxtezLvXfaU4oUO85expPpjE1_3S1vBrmpcexPLlM=@protonmail.com>
References: <dac8de1c3cb7fc43f2f046285d3b03b9@richieburnett.co.uk>
 <2Hx3d9SgpS9UPD89NGub5KM56BzpL1CTliCvd90opIVb19nEbVLkwTnzvbgZjmX59EnxtezLvXfaU4oUO85expPpjE1_3S1vBrmpcexPLlM=@protonmail.com>
Message-ID: <E894BA4E-FD68-48EE-BD3A-39A88A6FCB5A@scale.la>

Jam El Mar states that it was either the JD-800 or System 700 in this ?revisitation? after 30 years video here
https://www.youtube.com/watch?v=MQVCqDPxF-0

Quite the wide swing there between synthesis types there.


Todd
> On Aug 14, 2024, at 2:31 PM, tpuefke via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> Hi Richie,
> 
> I believe I'm hearing high frequency modulation of (assuming) a bandpass filter, likely from a noise or audio source in the first example. The additional effect sounds very much like sample rate reduction indeed. Perhaps using an analog sample and hold at (comparatively) low clock speed, because it sounds very gritty. But could just as well be some kind of old school digital lo-fi effect, not sure.
> 
> In the second example I would say the filter modulation sounds a lot more regular, like from a faster LFO. Not hearing the aliasing-type effect like in the first one.
> 
> I would say both synth sounds are using at least two oscillators, and I have a feeling that square or pulse waves are involved. 
> 
> This is much fun. Very interested to hear people's suggestions.
> 
> Cheers,
> Tom
> 
> 
> On Wednesday, August 14th, 2024 at 19:42, rburnett at richieburnett.co.uk <rburnett at richieburnett.co.uk> wrote:
> 
>> 
>> 
>> Hi synth fans,
>> 
>> I'd like to pick your brains about how a particular synth sound was
>> created... I've always liked this sound that features on a number of
>> Jam and Spoon tracks (Rolf Ellmer & Markus Loffel) from the 90's and
>> early 2000's. It sounds like a resonant lowpass filter sweep but there
>> is something else to it, and I've never heard anything quite like it
>> anywhere else. The resonance seems to have a dirty and distinctly harsh
>> "scratchy" sound to it which I think works nicely in the genre they used
>> it in. It appears all over their album "Tripomatic Fairyfales 2001"
>> like it's their trademark sound! I'd love to know what piece of kit is
>> used to produce this sound if anyone knows?
>> 
>> I'm guessing it might be the result of filter FM or some kind of
>> overdriven digital filter, but I've never managed to get anything like
>> this out of any of my filters, digital or analogue. Or maybe it's some
>> post processing like decimation, although it doesn't sound quite like
>> aliasing to my ears either.
>> 
>> The best example I've found is at the start of "Follow Me":
>> 
>> https://www.youtube.com/watch?v=UfR7o8NI2W0
>> The synth starts at 0:00 and is initially quite smooth and clean
>> sounding while the filter is closed down, but gets really scratchy from
>> 0:30 onwards as the filter opens up.
>> 
>> There are other examples in "Tripomatic Fairytales 2001" too:
>> https://www.youtube.com/watch?v=vvf4wwDpaCw
>> The synth starts at 17:35 but getting scratchy from 18:20 throughout
>> that song.
>> The synth starts on another track at 49:00 but getting scratchy from
>> 49:10 onwards to the end of that song.
>> 
>> Any ideas? This has been bugging me for about 20 years, so I'm all
>> ears! ;-))
>> 
>> -Richie,
>> 
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

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From oakleysound at gmail.com  Wed Aug 14 23:20:59 2024
From: oakleysound at gmail.com (Tony Allgood)
Date: Wed, 14 Aug 2024 22:20:59 +0100
Subject: [sdiy] Mystery synth sound
In-Reply-To: <dac8de1c3cb7fc43f2f046285d3b03b9@richieburnett.co.uk>
References: <dac8de1c3cb7fc43f2f046285d3b03b9@richieburnett.co.uk>
Message-ID: <ebee6db4-9106-4b7c-9b93-aae7bd4f4fb1@gmail.com>

I think 'Follow Me' is audio frequency clocked sample and hold. The 
audio is being sampled at a rate determined by a VCO whose frequency is 
being played with.

The 'Jam and Spoon' is possibly audio rate filter FM. They're possibly 
just playing with the cut-off frequency, modulation frequency and depth.

Tony

From chromatest at chromatest.net  Thu Aug 15 01:07:08 2024
From: chromatest at chromatest.net (Chromatest J. Pantsmaker)
Date: Wed, 14 Aug 2024 16:07:08 -0700
Subject: [sdiy] Repair part question, Korg DDM-110/220 buttons
In-Reply-To: <B10AEFAA-9FF8-4FC5-870F-1CC9BDC78FAA@me.com>
References: <8877E459-9426-4048-ACFE-3B0205143740@me.com>
 <CADpm=3Ezmk0wa6wwo98egD=n=-WnuoKDGpH0K1x8UarMYpkjgA@mail.gmail.com>
 <079A3289-A707-4B2B-9A54-64CEC1639120@me.com>
 <B10AEFAA-9FF8-4FC5-870F-1CC9BDC78FAA@me.com>
Message-ID: <CADpm=3HKC5PPHTu5FHva5+zRW2Y9qGS57cUpzW6Dj2-jcs3Gqw@mail.gmail.com>

Thanks much for that Benjamin!

Unfortunately, that is not the source of my trouble.  After searching and
testing that area, I finally decided to swap the KLM-603 board from my
DDM-110 and the problem persists with the DDM-220.  The 110 works perfectly
with either 603 board while the 220 has the same non-working status with
either 603 board.  I'll drag out my scope to see where the clock gets
swallowed up.
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From kogz23 at yahoo.com  Thu Aug 15 04:15:29 2024
From: kogz23 at yahoo.com (al spitzley)
Date: Thu, 15 Aug 2024 02:15:29 +0000 (UTC)
Subject: [sdiy] Roland Jupiter 6 issues
In-Reply-To: <CAHy3N6DF29HLAz=V-bU4xguFZPFFtu+VxNrpuUGv2MzuC=mB-g@mail.gmail.com>
References: <581936990.2448700.1722995972304.ref@mail.yahoo.com>
 <581936990.2448700.1722995972304@mail.yahoo.com>
 <3521001d-73c8-4a43-8f56-681f4c5ea034@gmail.com>
 <CAHy3N6B-Nj=cs_RZa1hvSrsNOPMKuyYdj0ZGy_eCZxNJqNfYkw@mail.gmail.com>
 <676353605.2660928.1723064932689@mail.yahoo.com>
 <215800599.2717459.1723083889354@mail.yahoo.com>
 <4E04F604-2BE1-4AF5-815D-166C1A3D4C90@adambaby.com>
 <CAHy3N6DF29HLAz=V-bU4xguFZPFFtu+VxNrpuUGv2MzuC=mB-g@mail.gmail.com>
Message-ID: <482386014.4217039.1723688129769@mail.yahoo.com>

 Ok, finally have something to report. Sorry for the radio silence!Thank you for clearing up the confusing, to me anyway, patch layout.I was using a PC to try loading the patches originally, with and without a preamp to boost the signal.I then tried loading the factory patches with that eprom file that is out there, According to the instructions the message I got back from the synth was that the patches were successfully loaded in to the ram. Still crashed the machine though and the patches didn't sound right.So I took a break from the digital/cpu side and decided to attack the multiple issues I had on one of the voice boards. 2 3340s, 1 3360, several 4051s and an opamp later and the voice board was fixed.I tried loading the patches from a Macbook and amazingly it loaded first time.Now I'm not sure if it was the playback device or the issues on the voice board somehow playing havoc with the patch memory. I'm too nervous to verify by trying the PC again. It works so I want to leave it!!Anyway, thank you for all the suggestions. It definitely helped me maintain some sanity during this repair!CheersAl

    On Thursday, August 8, 2024 at 02:43:59 PM PDT, Nathan Trites <nathan at idmclassics.net> wrote:  
 
 Yup - the?memory naming on the 6 is confusing and obscures the relationship. Patch Preset and Patch Memory have what gets called a Performance/Patch or Patch/Tone relationship on some other synths.?
Expanding on what Adam said since I had this typed up yesterday but never sent... "Patch Preset" (Preset switch ON. Bank A/B/C/D & memory 1-8) remembers the split/layer configuration, arp settings, and the sound assignment to the lower/upper, etc. Patch Memory (Preset switch OFF, then your bank?& memory slot selection) is the actual sound being used on the Patch Preset. A Patch Preset calls 1 or 2 tones from Patch Memory.?
I'm not 100% on this and would need to check my JP6 sometime, but I believe the behavior Al is seeing is normal because if you modify Patch Preset A1, which is calling Patch Memory A1 and A2, when you make changes and save it to Patch Preset A2 its?also overwriting Patch Memory A1 and A2.
Al, what's your playback device for the tape backup?
Nathan
On Wed, Aug 7, 2024 at 11:13?PM Adam (synthDIY) <synthdiy at adambaby.com> wrote:

When you say "Patch led" are you referring to the Patch Preset LED?I don't own a JP6 but on the JP8 Roland employ a potentially confusing terminology, and I think they persisted with the JP6:A "patch" is a single memory slot containing the synth voice parameters for VCO VCF VCA etc.A "Patch Preset" is a special memory that holds two such patches along with their voice assignments/splits/glide etc
A


On 8 Aug 2024, at 12:24?PM, al spitzley via Synth-diy <synth-diy at synth-diy.org> wrote:
A quick question for Tony. When you say to program all the patches with an Init patch are you referring to?that the Factory patches with the Patch led lit?Cheers?Al


Sent from Yahoo Mail for iPhone


On Wednesday, August 7, 2024, 2:08 PM, al spitzley <kogz23 at yahoo.com> wrote:

Thanks for the ideas.I tried cranking the gain and no luck. Different results each time. Aargh!When it ?freezes? with the Tape button lit it will not go into load. The only way to get out of it is to hit the Tape button. Occasionally it completely locks up and I have to restart.I?m having issues saving to the factory patch area. If I create a patch on A1, save it, create a different one on A2 (for example) it will save but also save into A1 or any previous patches I?ve just created. So I can?t create different patches when the Patch button is lit. I?m thinking this could be user error and confusion over factory patches vs user patches.I?m going to try loading factory patches using a utility?eprom I found on the internet. I?ll be away for a few days and will report back.Thanks again?Al


Sent from Yahoo Mail for iPhone


On Wednesday, August 7, 2024, 11:55 AM, Nathan Trites <nathan at idmclassics.net> wrote:

On one Jupiter 6 I did, I was convinced the RAM was bad because no matter what there would always be a few corrupt patches that would lock up the synth. Eventually I figured out the patches that failed had to do with the level I was doing the playback at, and it was consistent across every interface I have - the only solution was giving the tape signal an absurd amount of gain thru a preamp. If I recall the dump I got online was already normalized, and the cassette interface on the synth had no issues, so unless the CPU had a problem, it was possibly due to the frequency response of the specific dump or something like that. Ever since then I've done cassette restores on Jupiter 6's by giving it a ton of gain thru a mixer channel, and haven't had any patch dump issues yet. All that to say - don't rule out cranking the gain like crazy.?
I've also had to do what Tony describes to get JP-6 memory to work correctly?

Nathan
On Wed, Aug 7, 2024 at 3:28?AM Tony Allgood via Synth-diy <synth-diy at synth-diy.org> wrote:

I have seen similar behaviour before with various JP-6 units over the 
years. What has always fixed it is going into manual mode. Create a 
simple standard 'init' patch, something like a classic analogue pluck 
sound will do. But it doesn't matter - just something you know the sound of.

Then program that same patch into *every* memory location.

Now check every patch still sounds the same and no crashes occur.

Reload the factory patches via tape if you wish.

However, if it is your own patches you are trying to load, then it could 
be that it is those that are corrupted. In this case, it is probably 
better to reprogram those sounds in manual mode.

Tony

www.oakleysound.com
________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
Selling or trading? Use marketplace at synth-diy.org


________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
Selling or trading? Use marketplace at synth-diy.org






________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
Selling or trading? Use marketplace at synth-diy.org


________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
Selling or trading? Use marketplace at synth-diy.org

  
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From electrocontinuo at gmail.com  Thu Aug 15 04:42:28 2024
From: electrocontinuo at gmail.com (Peter Pearson)
Date: Wed, 14 Aug 2024 22:42:28 -0400
Subject: [sdiy] Roland Jupiter 6 issues
In-Reply-To: <482386014.4217039.1723688129769@mail.yahoo.com>
References: <581936990.2448700.1722995972304.ref@mail.yahoo.com>
 <581936990.2448700.1722995972304@mail.yahoo.com>
 <3521001d-73c8-4a43-8f56-681f4c5ea034@gmail.com>
 <CAHy3N6B-Nj=cs_RZa1hvSrsNOPMKuyYdj0ZGy_eCZxNJqNfYkw@mail.gmail.com>
 <676353605.2660928.1723064932689@mail.yahoo.com>
 <215800599.2717459.1723083889354@mail.yahoo.com>
 <4E04F604-2BE1-4AF5-815D-166C1A3D4C90@adambaby.com>
 <CAHy3N6DF29HLAz=V-bU4xguFZPFFtu+VxNrpuUGv2MzuC=mB-g@mail.gmail.com>
 <482386014.4217039.1723688129769@mail.yahoo.com>
Message-ID: <CA+qbVc8q2MWpOuyQRE+zYXy0FQdrQ=WX2CovGJvrmmQ2ts0P0w@mail.gmail.com>

The JP6 wants a REALLY hot signal when loading tape dumps (like in the
red).  I think also pretty fussy about getting the level right in the
pocket so it accepts the data transfer.  Totally possible that could have
been part of your issue.

On Wed, Aug 14, 2024 at 10:20?PM al spitzley via Synth-diy <
synth-diy at synth-diy.org> wrote:

> Ok, finally have something to report. Sorry for the radio silence!
> Thank you for clearing up the confusing, to me anyway, patch layout.
> I was using a PC to try loading the patches originally, with and without a
> preamp to boost the signal.
> I then tried loading the factory patches with that eprom file that is out
> there, According to the instructions the message I got back from the synth
> was that the patches were successfully loaded in to the ram. Still crashed
> the machine though and the patches didn't sound right.
> So I took a break from the digital/cpu side and decided to attack the
> multiple issues I had on one of the voice boards. 2 3340s, 1 3360, several
> 4051s and an opamp later and the voice board was fixed.
> I tried loading the patches from a Macbook and amazingly it loaded first
> time.
> Now I'm not sure if it was the playback device or the issues on the voice
> board somehow playing havoc with the patch memory. I'm too nervous to
> verify by trying the PC again. It works so I want to leave it!!
> Anyway, thank you for all the suggestions. It definitely helped me
> maintain some sanity during this repair!
> Cheers
> Al
>
> On Thursday, August 8, 2024 at 02:43:59 PM PDT, Nathan Trites <
> nathan at idmclassics.net> wrote:
>
>
> Yup - the memory naming on the 6 is confusing and obscures the
> relationship. Patch Preset and Patch Memory have what gets called a
> Performance/Patch or Patch/Tone relationship on some other synths.
>
> Expanding on what Adam said since I had this typed up yesterday but never
> sent... "Patch Preset" (Preset switch ON. Bank A/B/C/D & memory 1-8)
> remembers the split/layer configuration, arp settings, and the sound
> assignment to the lower/upper, etc. Patch Memory (Preset switch OFF, then
> your bank & memory slot selection) is the actual sound being used on the
> Patch Preset. A Patch Preset calls 1 or 2 tones from Patch Memory.
>
> I'm not 100% on this and would need to check my JP6 sometime, but I
> believe the behavior Al is seeing is normal because if you modify Patch
> Preset A1, which is calling Patch Memory A1 and A2, when you make changes
> and save it to Patch Preset A2 its also overwriting Patch Memory A1 and A2.
>
> Al, what's your playback device for the tape backup?
>
> Nathan
>
> On Wed, Aug 7, 2024 at 11:13?PM Adam (synthDIY) <synthdiy at adambaby.com>
> wrote:
>
> When you say "Patch led" are you referring to the Patch Preset LED?
> I don't own a JP6 but on the JP8 Roland employ a potentially confusing
> terminology, and I think they persisted with the JP6:
> A "patch" is a single memory slot containing the synth voice parameters
> for VCO VCF VCA etc.
> A "Patch Preset" is a special memory that holds two such patches along
> with their voice assignments/splits/glide etc
>
> A
>
> On 8 Aug 2024, at 12:24?PM, al spitzley via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
> A quick question for Tony. When you say to program all the patches with an
> Init patch are you referring to that the Factory patches with the Patch led
> lit?
> Cheers
> Al
>
>
> Sent from Yahoo Mail for iPhone
> <https://mail.onelink.me/107872968?pid=nativeplacement&c=Global_Acquisition_YMktg_315_Internal_EmailSignature&af_sub1=Acquisition&af_sub2=Global_YMktg&af_sub3=&af_sub4=100000604&af_sub5=EmailSignature__Static_>
>
> On Wednesday, August 7, 2024, 2:08 PM, al spitzley <kogz23 at yahoo.com>
> wrote:
>
> Thanks for the ideas.
> I tried cranking the gain and no luck. Different results each time. Aargh!
> When it ?freezes? with the Tape button lit it will not go into load. The
> only way to get out of it is to hit the Tape button. Occasionally it
> completely locks up and I have to restart.
> I?m having issues saving to the factory patch area. If I create a patch on
> A1, save it, create a different one on A2 (for example) it will save but
> also save into A1 or any previous patches I?ve just created. So I can?t
> create different patches when the Patch button is lit. I?m thinking this
> could be user error and confusion over factory patches vs user patches.
> I?m going to try loading factory patches using a utility eprom I found on
> the internet. I?ll be away for a few days and will report back.
> Thanks again
> Al
>
>
> Sent from Yahoo Mail for iPhone
> <https://mail.onelink.me/107872968?pid=nativeplacement&c=Global_Acquisition_YMktg_315_Internal_EmailSignature&af_sub1=Acquisition&af_sub2=Global_YMktg&af_sub3=&af_sub4=100000604&af_sub5=EmailSignature__Static_>
>
> On Wednesday, August 7, 2024, 11:55 AM, Nathan Trites <
> nathan at idmclassics.net> wrote:
>
> On one Jupiter 6 I did, I was convinced the RAM was bad because no matter
> what there would always be a few corrupt patches that would lock up the
> synth. Eventually I figured out the patches that failed had to do with the
> level I was doing the playback at, and it was consistent across every
> interface I have - the only solution was giving the tape signal an absurd
> amount of gain thru a preamp. If I recall the dump I got online was already
> normalized, and the cassette interface on the synth had no issues, so
> unless the CPU had a problem, it was possibly due to the frequency response
> of the specific dump or something like that. Ever since then I've done
> cassette restores on Jupiter 6's by giving it a ton of gain thru a mixer
> channel, and haven't had any patch dump issues yet. All that to say - don't
> rule out cranking the gain like crazy.
>
> I've also had to do what Tony describes to get JP-6 memory to work
> correctly
>
> Nathan
>
> On Wed, Aug 7, 2024 at 3:28?AM Tony Allgood via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
> I have seen similar behaviour before with various JP-6 units over the
> years. What has always fixed it is going into manual mode. Create a
> simple standard 'init' patch, something like a classic analogue pluck
> sound will do. But it doesn't matter - just something you know the sound
> of.
>
> Then program that same patch into *every* memory location.
>
> Now check every patch still sounds the same and no crashes occur.
>
> Reload the factory patches via tape if you wish.
>
> However, if it is your own patches you are trying to load, then it could
> be that it is those that are corrupted. In this case, it is probably
> better to reprogram those sounds in manual mode.
>
> Tony
>
> www.oakleysound.com
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From mr at analogue.org  Thu Aug 15 09:10:36 2024
From: mr at analogue.org (Mattias Rickardsson)
Date: Thu, 15 Aug 2024 09:10:36 +0200
Subject: [sdiy] Sampler with tape dump?
In-Reply-To: <A466E4BA-F660-4953-A96C-9D2FA2103BA8@scale.la>
References: <CAP92RBUd_ZNt5DzFzF+3Uu2q9Fm9PZug75znNQZFKpi62=Xx+A@mail.gmail.com>
 <A466E4BA-F660-4953-A96C-9D2FA2103BA8@scale.la>
Message-ID: <CAP92RBU-S5XibPz-HQZ9xMwp4qxJ5_DzYzHPVH5NHVz6NLW3vA@mail.gmail.com>

On Tue, 13 Aug 2024 at 22:37, Todd Sines <sines_list at scale.la> wrote:

> On the subject of tape disintegration, cue William Basinski
> https://en.m.wikipedia.org/wiki/The_Disintegration_Loops
>

Yes, a VERY nice related artwork recommended to everyone who has not
experienced it yet. Especially strong in the film version with the
slowly evolving smoke formations of the 9/11 aftermath during the decaying
twilight that makes the movie camera struggle more and more to keep focus...
https://www.youtube.com/watch?v=ObdZ8lhC0f0

/mr
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From mr at analogue.org  Thu Aug 15 09:49:02 2024
From: mr at analogue.org (Mattias Rickardsson)
Date: Thu, 15 Aug 2024 09:49:02 +0200
Subject: [sdiy] Mystery synth sound - One more chance?
Message-ID: <CAP92RBVO=o74_8j=Vm0pu--pwRaqKhnyJ9+X_hWgn6gDurv3-Q@mail.gmail.com>

Hi synth fans,

When we're into unknown synth sound creation and favorite sounds from
mysterious sources, I can't help also asking if anyone knows anything about
the bassline sound of "One More Chance" by the Pet Shop Boys in the
re-recorded version kicking off their follow-up album "Actually" from 1987.

https://www.youtube.com/watch?v=prntbdZiJSg

The mystery bass sound first appears at 1:30.
In the bridge starting at 3:33, the bassline goes for a nice little
promenade, then returns.

As with many sounds on well-produced recordings, it might be a sound
sculpted by doubling or tripling different synths or other sources, and
also might be heavily treated with effects. This might make it impossible
to pinpoint or even find documentation of. It might also be made with
"uninteresting" synths, getting its interesting synthesis qualities
entirely by treatments and production. Still, it's a sound with some unique
magical qualities in a masterpiece of a track that never fails to give me
goosebumps, and I just can't let it go unknown.

Any ideas?  This mystery bass sound has been bugging me for about 35 years,
so I'm all
ears! ;-)

/mr  -  riding the wave after Richie's synth sound exploration
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From oakleysound at gmail.com  Thu Aug 15 10:15:54 2024
From: oakleysound at gmail.com (Tony Allgood)
Date: Thu, 15 Aug 2024 09:15:54 +0100
Subject: [sdiy] Mystery synth sound - One more chance?
In-Reply-To: <CAP92RBVO=o74_8j=Vm0pu--pwRaqKhnyJ9+X_hWgn6gDurv3-Q@mail.gmail.com>
References: <CAP92RBVO=o74_8j=Vm0pu--pwRaqKhnyJ9+X_hWgn6gDurv3-Q@mail.gmail.com>
Message-ID: <0da4f633-c5df-46cd-9047-aa573b718255@gmail.com>

I'm going to say DX-7.

From oakleysound at gmail.com  Thu Aug 15 10:16:16 2024
From: oakleysound at gmail.com (Tony Allgood)
Date: Thu, 15 Aug 2024 09:16:16 +0100
Subject: [sdiy] Mystery synth sound - One more chance?
In-Reply-To: <CAP92RBVO=o74_8j=Vm0pu--pwRaqKhnyJ9+X_hWgn6gDurv3-Q@mail.gmail.com>
References: <CAP92RBVO=o74_8j=Vm0pu--pwRaqKhnyJ9+X_hWgn6gDurv3-Q@mail.gmail.com>
Message-ID: <a40f5285-35f7-40c3-b7fa-417f2847a030@gmail.com>

I'm going to say DX-7.

From bloke at blokezero.com  Thu Aug 15 10:59:20 2024
From: bloke at blokezero.com (bloke at blokezero.com)
Date: Thu, 15 Aug 2024 09:59:20 +0100
Subject: [sdiy] Mystery synth sound - One more chance?
In-Reply-To: <CAP92RBVO=o74_8j=Vm0pu--pwRaqKhnyJ9+X_hWgn6gDurv3-Q@mail.gmail.com>
References: <CAP92RBVO=o74_8j=Vm0pu--pwRaqKhnyJ9+X_hWgn6gDurv3-Q@mail.gmail.com>
Message-ID: <3D11CC13-E762-4DA3-874D-D6AEDB181A43@blokezero.com>

I'm going to say DX7 + Jupiter 6 (or something similar), there is a kind of thick slightly filtered quality to the sound that I think you'd struggle to replicate with just a DX.

Check this video: https://youtu.be/9FRNcJAkEMw?feature=shared&t=637 (I've set it to start 10:30mins in so you don't have to hear about sting and his double bass :eyeroll:). He says the bass on Westend Girls was a DX7, a Jupiter 6 and a tuned bass drum sample - layered, then goes on to demonstrate the effect. This is on the same principle that doubling an electric bass sound with a distorted electric bass, or a guitar playing the same part an octave up thickens the sound. It's a fun video!

Alex

> On 15 Aug 2024, at 08:49, Mattias Rickardsson <mr at analogue.org> wrote:
> 
> Hi synth fans,
> 
> When we're into unknown synth sound creation and favorite sounds from mysterious sources, I can't help also asking if anyone knows anything about the bassline sound of "One More Chance" by the Pet Shop Boys in the re-recorded version kicking off their follow-up album "Actually" from 1987.
> 
> https://www.youtube.com/watch?v=prntbdZiJSg
> 
> The mystery bass sound first appears at 1:30.
> In the bridge starting at 3:33, the bassline goes for a nice little promenade, then returns.
> 
> As with many sounds on well-produced recordings, it might be a sound sculpted by doubling or tripling different synths or other sources, and also might be heavily treated with effects. This might make it impossible to pinpoint or even find documentation of. It might also be made with "uninteresting" synths, getting its interesting synthesis qualities entirely by treatments and production. Still, it's a sound with some unique magical qualities in a masterpiece of a track that never fails to give me goosebumps, and I just can't let it go unknown.
> 
> Any ideas?  This mystery bass sound has been bugging me for about 35 years, so I'm all
> ears! ;-)
> 
> /mr  -  riding the wave after Richie's synth sound exploration
> ________________________________________________________
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From synthdiy at adambaby.com  Thu Aug 15 13:34:35 2024
From: synthdiy at adambaby.com (Adam (synthDIY))
Date: Thu, 15 Aug 2024 21:34:35 +1000
Subject: [sdiy] Mystery synth sound - One more chance?
In-Reply-To: <3D11CC13-E762-4DA3-874D-D6AEDB181A43@blokezero.com>
References: <CAP92RBVO=o74_8j=Vm0pu--pwRaqKhnyJ9+X_hWgn6gDurv3-Q@mail.gmail.com>
 <3D11CC13-E762-4DA3-874D-D6AEDB181A43@blokezero.com>
Message-ID: <45C5E993-16BF-47D1-8725-D1C70DD7B382@adambaby.com>

Wow, great video, interesting character!
I must concur about the TX81Z - it's always switched on and set to "Lately Bass" around here, such a great foundation sound. Just tweak the mod operators and the sustain a little depending on the tempo...

But the PSB bass sound I think could be an FM bass going through a manual analogue filter - it "talks" a little differently to a pure FM source I feel... 

A

> On 15 Aug 2024, at 6:59?PM, bloke--- via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> I'm going to say DX7 + Jupiter 6 (or something similar), there is a kind of thick slightly filtered quality to the sound that I think you'd struggle to replicate with just a DX.
> 
> Check this video: https://youtu.be/9FRNcJAkEMw?feature=shared&t=637 (I've set it to start 10:30mins in so you don't have to hear about sting and his double bass :eyeroll:). He says the bass on Westend Girls was a DX7, a Jupiter 6 and a tuned bass drum sample - layered, then goes on to demonstrate the effect. This is on the same principle that doubling an electric bass sound with a distorted electric bass, or a guitar playing the same part an octave up thickens the sound. It's a fun video!
> 
> Alex
> 
>> On 15 Aug 2024, at 08:49, Mattias Rickardsson <mr at analogue.org> wrote:
>> 
>> Hi synth fans,
>> 
>> When we're into unknown synth sound creation and favorite sounds from mysterious sources, I can't help also asking if anyone knows anything about the bassline sound of "One More Chance" by the Pet Shop Boys in the re-recorded version kicking off their follow-up album "Actually" from 1987.
>> 
>> https://www.youtube.com/watch?v=prntbdZiJSg
>> 
>> The mystery bass sound first appears at 1:30.
>> In the bridge starting at 3:33, the bassline goes for a nice little promenade, then returns.
>> 
>> As with many sounds on well-produced recordings, it might be a sound sculpted by doubling or tripling different synths or other sources, and also might be heavily treated with effects. This might make it impossible to pinpoint or even find documentation of. It might also be made with "uninteresting" synths, getting its interesting synthesis qualities entirely by treatments and production. Still, it's a sound with some unique magical qualities in a masterpiece of a track that never fails to give me goosebumps, and I just can't let it go unknown.
>> 
>> Any ideas?  This mystery bass sound has been bugging me for about 35 years, so I'm all
>> ears! ;-)
>> 
>> /mr  -  riding the wave after Richie's synth sound exploration
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
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From rburnett at richieburnett.co.uk  Sat Aug 17 14:55:25 2024
From: rburnett at richieburnett.co.uk (Richie Burnett)
Date: Sat, 17 Aug 2024 13:55:25 +0100
Subject: [sdiy] Mystery synth sound
In-Reply-To: <ebee6db4-9106-4b7c-9b93-aae7bd4f4fb1@gmail.com>
References: <dac8de1c3cb7fc43f2f046285d3b03b9@richieburnett.co.uk>
 <ebee6db4-9106-4b7c-9b93-aae7bd4f4fb1@gmail.com>
Message-ID: <C244C5136F194CE0A6A14428243F9049@DESKTOPUHPK2VO>

Thanks for all the suggestions on-list and off-list guys :-)  I've got some 
ideas to try now.

Mattias your PSB bassline example definitely sounds FM'y to me, but my ears 
are a little old.  I liked the YouTube video about layering analogue and FM 
bass to get the best of both worlds.

Cheers,

-Richie,



-----Original Message----- 
From: Tony Allgood via Synth-diy
Sent: Wednesday, August 14, 2024 10:20 PM
To: SynthDIY
Subject: Re: [sdiy] Mystery synth sound

I think 'Follow Me' is audio frequency clocked sample and hold. The
audio is being sampled at a rate determined by a VCO whose frequency is
being played with.

The 'Jam and Spoon' is possibly audio rate filter FM. They're possibly
just playing with the cut-off frequency, modulation frequency and depth.

Tony
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From cheater00social at gmail.com  Fri Aug 23 13:08:29 2024
From: cheater00social at gmail.com (cheater cheater)
Date: Fri, 23 Aug 2024 13:08:29 +0200
Subject: [sdiy] Best AVAILABLE OTA for building new designs?
In-Reply-To: <BY3PR19MB51404ECA9DEDC0DECEB305B4C4862@BY3PR19MB5140.namprd19.prod.outlook.com>
References: <5C6F1B233EF44C8EB0D96A6CE2ED1E19@david78c70950b>
 <F5F50AEC-90BD-4619-B33C-8AA78AB2D0AD@gmail.com>
 <CA+qbVc8P4cMmkfF79wY0L5yV2iPg2MHynnBDmm55Vyig0qdb7w@mail.gmail.com>
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 <CA+wjhVs22JT+7ut6fqgRc-8w5YOESABS0GSMkK4LJOaKpGjoMQ@mail.gmail.com>
 <20240812081321.GA21657@gjcp.net>
 <CWLP265MB7132BD2046DCB5DAA6E8A496DB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAKcdib3h=KQbEd4_OFo6LVkBunABet+Dk1Ub9eaQtNo0zhkCKg@mail.gmail.com>
 <CWLP265MB713252EC8F600902DE397EDBDB852@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <BBDA54C7-0A12-4759-9226-017AC9E5FDDE@adambaby.com>
 <20240813064730.GA27812@gjcp.net>
 <CAP92RBV6YaWVyQ1331sfE+ttSayUCVc7RVBJExDAge4irY10uA@mail.gmail.com>
 <CWLP265MB7132C2FD9FFE55996FEDA4A4DB862@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <BY3PR19MB51404ECA9DEDC0DECEB305B4C4862@BY3PR19MB5140.namprd19.prod.outlook.com>
Message-ID: <CAGn5V-9jguQDAOPJp0ziuKXHD8+yoJRndAKWdppMtYVS6Uc3LA@mail.gmail.com>

What you want to do is to sum one note from all octaves in one op amp,
this way distortion will be fully harmonic for the most part except
for oscillating filters. Then, sum all 12 notes together.

You probably also want to add some sort of unison option that divides
the voice cards in two so that eg C5 now plays C3 in addition to the
original C3 card. You can set the unison to 2 or 4 and transpose. The
above arrangement with op amps will work well for that.

IMO you shouldn't be doing any compression in a keyboard. Being able
to vary the volume and therefore dynamics of a song by varying the
amount of notes being played is part of musical training for any
keyboard musician. Subverting that is a bad idea. Outboard compressors
exist and can be used. At least make it optional.

If you want good air circulation around your chips with as few fans as
possible, arrange your cards in a very long duct, like an Xbox Series
X. Leave at least 8mm between cards to prevent pressure build up and
use a slow static pressure fan from noctua. Note that the duct has to
be sealed, so that air doesn't seep out, or you will not get good
ventillation by the final cards.

You want the first cards to be the highest notes (get the freshest
air) and the last ones to be the lowest notes (if those drift it
sounds good). High notes drifting sounds bad, low notes drifting
sounds good.

You probably want a duct where you can unscrew the top and inspect the
cards. Add a gasket between the parts that screw together, like in a
water sealed electrical box. You can 3D print the duct, and leave
space for some rubber piping or one of those stick-on window gaskets
you can buy in a home improvement store.

On Wed, Aug 14, 2024 at 7:50?PM el macaco via Synth-diy
<synth-diy at synth-diy.org> wrote:
>
> The Alesis Andromeda has a mod source of a voltage that increases with the number of voices.
>
> I think in the tips and tricks document they mention this to reduce clipping in popy patches with loud monosynth like voices.
>
> Es
>
> Get Outlook for iOS
> ________________________________
> From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Mike Bryant <mbryant at futurehorizons.com>
> Sent: Tuesday, August 13, 2024 4:38:15 AM
> To: Mattias Rickardsson <mr at analogue.org>; Gordonjcp <gordonjcp at gjcp.net>
> Cc: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
> Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?
>
> The overload problem is one reason to go software.  Lots of algorithms available for setting the starting phases of each tone so that you are unlikely to overload the output.  Though avoid Schroeder-phase harmonic tone complexes which have an absolutely level envelope as the sound suddenly changes to a rising chirp.
> ________________________________
> From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Mattias Rickardsson <mr at analogue.org>
> Sent: 13 August 2024 10:06
> To: Gordonjcp <gordonjcp at gjcp.net>
> Cc: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
> Subject: Re: [sdiy] Best AVAILABLE OTA for building new designs?
>
> Sounds like we are starting to overdesign things a bit here... :-D
> Btw the "counting notes and keeping total volume constant" idea reminds me of one of the Unison modes in Roland Jupiter-4, where you depending on the number of depressed keys get 4-voice unison, 2x 2-voice unison, 3-voice poly or 4-voice poly. The level loss in this mode is remarkable and not very nice, especially when playing a 3-note chord and getting only 3 voices playing compared to playing 1 note and getting 4 voces playing.
>
> Anyway, I don't think the all-polyphonic voice summing issue should be too over-thought, but just try to combine
> - a summing where everything fits without clipping
> - a level control that can gain even more so that clipping could occur but a melody player would have enough output level.
>
> One of the trickiest bits is that resonant filters make peak levels vary a LOT more than you first might think, so you'll have to count with a peak voice level that is much higher than many typical sounds.
>
> Hopefully this is less of a problem in a true PS3100 voice where resonances are very moderate. In the gainstaging of polysynth designs in general, there is a huge advantage if you manage to keep filter resonances limited - everything level related gets easier, but on the other hand it's hard to make a firm resonance limiter without adding unwanted distortion or side effects to the filter sound.
>
> /mr
>
> On Tue, 13 Aug 2024 at 08:49, Gordonjcp <gordonjcp at gjcp.net> wrote:
>
> On Tue, Aug 13, 2024 at 07:54:24AM +1000, Adam (synthDIY) wrote:
> >
> >
> > > On 12 Aug 2024, at 11:38?PM, Mike Bryant <mbryant at futurehorizons.com> wrote:
> > >
> > > I think you need to watch some videos of the late Keith Emerson.  He'd happily have twenty or more keys pressed on a Hammond, some of course held down with knives :-)
> >
> > David, you might be able to use this as a "feature"...  have a front panel control labelled "Knife Factor" that switches in a compressor with auto-make-up gain...
>
> Given that compressors work by controlling their gain based on output level - a negative feedback loop - I have this feeling that you could probably sum all the VCA CVs to give a "total output demand" voltage, which could be fed back to the DAC Vref (taking us back around to the multiplying DAC question) to depress the output voltage and keep the total level approximately constant.
>
> "Approximately" because you'd want it to have a bit of dynamics, you wouldn't want one note to be as loud as ten, but maybe five should be as loud as ten.
>
> --
> Gordonjcp
>
> ________________________________________________________
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