From commodorejohn at gmail.com  Thu Jul  2 01:03:21 2026
From: commodorejohn at gmail.com (John)
Date: Wed, 1 Jul 2026 16:03:21 -0700
Subject: [sdiy] TTSH - part/substitution questions
Message-ID: <20260701160321.00002ab1@gmail.com>

I'm in the process of speccing out a TTSH build, and there's a couple
things I'm curious about and hoping that someone more knowledgeable
than myself might be able to offer some insight on:

First, both the TTSH and the gate-boost BOM list ferrite beads with a
part # of FB_226 - but I cannot for the life of me find any such thing
online. Even a quoted-literal search returns nothing but results point-
ing right back to these BOMs. Is this some understood shorthand for the
specs on a generic ferrite bead? How does one read that?

Second, I'm sure I'm not remotely the first person to note that some of
the transistors required are, erm, unicorn poop, either completely un-
available outside of eBay or just wildly expensive :/ I'm curious, has
anyone worked out alternatives for these?

The 2N4392s are in the electronic switch, and go straight to the jacks;
AFAICT, they're just there to alternately restrict current flow on one
of the two paths?

The 2N3954 is a dual JFET used in the sine shaper; can two JFETs of
equivalent specs be used in its place, or is it important that they be
inna-can for tempco/symmetry purposes?

The 2N3958s go to what were discrete modules on the original. Per what
I can find, one is a buffer for the filter circuit; from my amateur
guesswork, it looks like it uses the ladder's output voltage to control
current flow between +15V and the offset trimmer (which I assume goes
to ground or -15V?) The other is in the S&H, and it looks like it may
serve *almost* the same function, except that it has source & drain for
one JFET reversed, where the filter has them both going the same way.
Is tempco/symmetry also important for these? If they're not matched &
coupled, would that manifest as asymmetric output, or a gap around 0V?

The BOM lists MJE182 and MJE172, which appear from what I can find to
be power transistors, but I don't see them in the power-supply section
and can't spot them anywhere else on the board diagrams I've found. If
I'm using a separate PSU, can I omit them?

From pete.hartman at gmail.com  Thu Jul  2 03:59:31 2026
From: pete.hartman at gmail.com (Pete Hartman)
Date: Wed, 1 Jul 2026 20:59:31 -0500
Subject: [sdiy] TTSH - part/substitution questions
In-Reply-To: <20260701160321.00002ab1@gmail.com>
References: <20260701160321.00002ab1@gmail.com>
Message-ID: <CACodTR95h26RKZPSsY+rdA-dtm+rNYyx_1R2Fk5STmxTHMEbDg@mail.gmail.com>

On Wed, Jul 1, 2026 at 6:11?PM John via Synth-diy
<synth-diy at synth-diy.org> wrote:
> First, both the TTSH and the gate-boost BOM list ferrite beads with a
> part # of FB_226 - but I cannot for the life of me find any such thing
> online. Even a quoted-literal search returns nothing but results point-
> ing right back to these BOMs. Is this some understood shorthand for the
> specs on a generic ferrite bead? How does one read that?

I'm not sure if it's a generic shorthand, but I don't think the
ferrites for these are intended to be anything fussy.  I have a drawer
full of this type of ferrite bead:
https://www.mouser.com/ProductDetail/Fair-Rite/2743002112?qs=X2DWwR3nihDJfxeTNAhF3w%3D%3D
and I just pulled from my own stock on hand.

BTW I looked at my images of rev1, rev2 and rev3 TTSH boards and I
could only find the beads on the rev1.... is that what you're
building?


> Second, I'm sure I'm not remotely the first person to note that some of
> the transistors required are, erm, unicorn poop, either completely un-
> available outside of eBay or just wildly expensive :/ I'm curious, has
> anyone worked out alternatives for these?

I built it with the Transistors as spec'd but then again, I bought a
rare parts kit from Thonk in the UK, so I didn't have to fuss about
with that.  I don't think they're still selling those :(


> The 2N3954 is a dual JFET used in the sine shaper; can two JFETs of
> equivalent specs be used in its place, or is it important that they be
> inna-can for tempco/symmetry purposes?

I would expect they need to be *matched* to each other, but aside from
that, I can't see any reason why the can makes it special


> The BOM lists MJE182 and MJE172, which appear from what I can find to
> be power transistors, but I don't see them in the power-supply section
> and can't spot them anywhere else on the board diagrams I've found. If
> I'm using a separate PSU, can I omit them?

Based on this I guess you're building a rev2 (or maybe later?).  On my
rev1 bom I have
 BD236 and BD237 which were power transistors for the amplifiers that
drove the speakers.
That's where I'd recommend to look, though I haven't dug into this
stuff in a long time now.


From commodorejohn at gmail.com  Thu Jul  2 08:44:50 2026
From: commodorejohn at gmail.com (John Ames)
Date: Wed, 1 Jul 2026 23:44:50 -0700
Subject: [sdiy] TTSH - part/substitution questions
In-Reply-To: <CACodTR95h26RKZPSsY+rdA-dtm+rNYyx_1R2Fk5STmxTHMEbDg@mail.gmail.com>
References: <20260701160321.00002ab1@gmail.com>
 <CACodTR95h26RKZPSsY+rdA-dtm+rNYyx_1R2Fk5STmxTHMEbDg@mail.gmail.com>
Message-ID: <20260701234450.313e13cd@coppelia.commodorejohn.com>

On Wed, 1 Jul 2026 20:59:31 -0500
Pete Hartman <pete.hartman at gmail.com> wrote:

> I'm not sure if it's a generic shorthand, but I don't think the
> ferrites for these are intended to be anything fussy.

Thanks, I kinda figured but this is more than a little beyond me.

> BTW I looked at my images of rev1, rev2 and rev3 TTSH boards and I
> could only find the beads on the rev1.... is that what you're
> building?

V.4, per the SynthCube product listing. BOM is at
https://product-downloads.freshclick.co.uk/uploads/187269622300ec56c723fa76ec709111.pdf
if you're curious.

> I built it with the Transistors as spec'd but then again, I bought a
> rare parts kit from Thonk in the UK, so I didn't have to fuss about
> with that.  I don't think they're still selling those :(

TBH I hadn't checked if they were, since Stupid Circumstances have made
international shipping stupid expensive :/

> I would expect they need to be *matched* to each other, but aside from
> that, I can't see any reason why the can makes it special

That's kinda what I'd guessed, but good to have some backup on this.
Curious what you'd be matching for - resistance? Switching time?

(On which note, obvious newbie question, but: since the ideal JFET is
open at 0V, is it a reasonable first-order approximation of "matching"
to compare resistance across a totally disconnected transistor, or is
it important to note variance in resistance across a range of gate
voltages...?)

> Based on this I guess you're building a rev2 (or maybe later?).  On my
> rev1 bom I have BD236 and BD237 which were power transistors for the
> amplifiers that drove the speakers.

Good to know, I'll have another look. If it's the speakers I'm omitting
those as well, but it'd be nice to minimize complications for the time
being.

From commodorejohn at gmail.com  Thu Jul  2 16:12:28 2026
From: commodorejohn at gmail.com (John Ames)
Date: Thu, 2 Jul 2026 07:12:28 -0700
Subject: [sdiy] TTSH - part/substitution questions
In-Reply-To: <SE2P216MB1508ACB6A852DE8E91F23457F7F52@SE2P216MB1508.KORP216.PROD.OUTLOOK.COM>
References: <20260701160321.00002ab1@gmail.com>
 <CACodTR95h26RKZPSsY+rdA-dtm+rNYyx_1R2Fk5STmxTHMEbDg@mail.gmail.com>
 <20260701234450.313e13cd@coppelia.commodorejohn.com>
 <SE2P216MB1508ACB6A852DE8E91F23457F7F52@SE2P216MB1508.KORP216.PROD.OUTLOOK.COM>
Message-ID: <20260702071228.7c4d112b@coppelia.commodorejohn.com>

On Thu, 2 Jul 2026 07:30:48 +0000
geoff james <minimoog1 at hotmail.com> wrote:

> Hi, Try this for your JFET matching.
> http://www.geofex.com/article_folders/fetmatch/fetmatch.htm

Oh bless you, that's massively useful.

From guatis at gmail.com  Fri Jul  3 18:43:11 2026
From: guatis at gmail.com (=?UTF-8?Q?Benjam=C3=ADn_Velasco?=)
Date: Fri, 3 Jul 2026 12:43:11 -0400
Subject: [sdiy] GRP Genesi
Message-ID: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>

I recently noticed this Arp Prosoloist clone:
https://www.grpsynthesizer.it/index.php/en/products/grp-vintage-genesi.html

Does anyone know anything about it? Is it a part by part clone (sans
keyboard)? How does it compare to the original? I'm curious about the
implementation of the VCO since the one in the Prosoloist/Pro DGX is
quite unique.

I've sent a couple of emails to the company with no answer.

Cheers

-- 
*Benjam?n Velasco Ossand?n*
Cel. +56 9 96344468
Casa. +56 2 27162400
Oficina. +56 2 29254154
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260703/097c31c6/attachment.htm>

From synthdiy at adambaby.com  Sat Jul  4 00:19:18 2026
From: synthdiy at adambaby.com (Adam (synthDIY))
Date: Sat, 4 Jul 2026 08:19:18 +1000
Subject: [sdiy] GRP Genesi
In-Reply-To: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
Message-ID: <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>

The YT video is 3 years old, yet the website isn't finished or very helpful - something tells me this didn't get very far...


A

> On 4 Jul 2026, at 02:43, Benjam?n Velasco via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> I recently noticed this Arp Prosoloist clone:
> https://www.grpsynthesizer.it/index.php/en/products/grp-vintage-genesi.html
> 
> Does anyone know anything about it? Is it a part by part clone (sans keyboard)? How does it compare to the original? I'm curious about the implementation of the VCO since the one in the Prosoloist/Pro DGX is quite unique.
> 
> I've sent a couple of emails to the company with no answer.
> 
> Cheers
> 
> --
> Benjam?n Velasco Ossand?n
> Cel. +56 9 96344468
> Casa. +56 2 27162400
> Oficina. +56 2 29254154
> ________________________________________________________
> 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

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260704/75384328/attachment.htm>

From guatis at gmail.com  Sat Jul  4 00:22:38 2026
From: guatis at gmail.com (=?UTF-8?Q?Benjam=C3=ADn_Velasco?=)
Date: Fri, 3 Jul 2026 18:22:38 -0400
Subject: [sdiy] GRP Genesi
In-Reply-To: <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
Message-ID: <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>

I became aware of these when recently some units started popping on Ebay,
Reverb, etc....Maybe leftovers? I'm intrigued...

El vie, 3 jul 2026 a las 18:19, Adam (synthDIY) (<synthdiy at adambaby.com>)
escribi?:

> The YT video is 3 years old, yet the website isn't finished or very
> helpful - something tells me this didn't get very far...
>
>
> A
>
> On 4 Jul 2026, at 02:43, Benjam?n Velasco via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
> I recently noticed this Arp Prosoloist clone:
> https://www.grpsynthesizer.it/index.php/en/products/grp-vintage-genesi.html
>
> Does anyone know anything about it? Is it a part by part clone (sans
> keyboard)? How does it compare to the original? I'm curious about the
> implementation of the VCO since the one in the Prosoloist/Pro DGX is
> quite unique.
>
> I've sent a couple of emails to the company with no answer.
>
> Cheers
>
> --
> *Benjam?n Velasco Ossand?n*
> Cel. +56 9 96344468
> Casa. +56 2 27162400
> Oficina. +56 2 29254154
> ________________________________________________________
> 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
>
>
>

-- 
*Benjam?n Velasco Ossand?n*
Cel. +56 9 96344468
Casa. +56 2 27162400
Oficina. +56 2 29254154
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260703/62749257/attachment.htm>

From mec.forumreader at gmail.com  Sat Jul  4 05:42:47 2026
From: mec.forumreader at gmail.com (Michael E Caloroso)
Date: Fri, 3 Jul 2026 23:42:47 -0400
Subject: [sdiy] GRP Genesi
In-Reply-To: <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
Message-ID: <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>

One was on display at Superbooth 2026.  A german magazine (Synmag) has a
review in an upcoming issue.

MC

On Fri, Jul 3, 2026 at 6:29?PM Benjam?n Velasco via Synth-diy <
synth-diy at synth-diy.org> wrote:

> I became aware of these when recently some units started popping on Ebay,
> Reverb, etc....Maybe leftovers? I'm intrigued...
>
> El vie, 3 jul 2026 a las 18:19, Adam (synthDIY) (<synthdiy at adambaby.com>)
> escribi?:
>
>> The YT video is 3 years old, yet the website isn't finished or very
>> helpful - something tells me this didn't get very far...
>>
>>
>> A
>>
>> On 4 Jul 2026, at 02:43, Benjam?n Velasco via Synth-diy <
>> synth-diy at synth-diy.org> wrote:
>>
>> I recently noticed this Arp Prosoloist clone:
>>
>> https://www.grpsynthesizer.it/index.php/en/products/grp-vintage-genesi.html
>>
>> Does anyone know anything about it? Is it a part by part clone (sans
>> keyboard)? How does it compare to the original? I'm curious about the
>> implementation of the VCO since the one in the Prosoloist/Pro DGX is
>> quite unique.
>>
>> I've sent a couple of emails to the company with no answer.
>>
>> Cheers
>>
>> --
>> *Benjam?n Velasco Ossand?n*
>> Cel. +56 9 96344468
>> Casa. +56 2 27162400
>> Oficina. +56 2 29254154
>> ________________________________________________________
>> 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
>>
>>
>>
>
> --
> *Benjam?n Velasco Ossand?n*
> Cel. +56 9 96344468
> Casa. +56 2 27162400
> Oficina. +56 2 29254154
> ________________________________________________________
> 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
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260703/c5c42025/attachment.htm>

From mec.forumreader at gmail.com  Sat Jul  4 05:45:21 2026
From: mec.forumreader at gmail.com (Michael E Caloroso)
Date: Fri, 3 Jul 2026 23:45:21 -0400
Subject: [sdiy] GRP Genesi
In-Reply-To: <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
Message-ID: <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>

Yes the VCO in the ProSoloist/DGX is often misunderstood as digital, it is
actually analog.  The patent explains it much better.  Definitely unique
and very very stable.

MC

On Fri, Jul 3, 2026 at 11:42?PM Michael E Caloroso <
mec.forumreader at gmail.com> wrote:

> One was on display at Superbooth 2026.  A german magazine (Synmag) has a
> review in an upcoming issue.
>
> MC
>
> On Fri, Jul 3, 2026 at 6:29?PM Benjam?n Velasco via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
>> I became aware of these when recently some units started popping on Ebay,
>> Reverb, etc....Maybe leftovers? I'm intrigued...
>>
>> El vie, 3 jul 2026 a las 18:19, Adam (synthDIY) (<synthdiy at adambaby.com>)
>> escribi?:
>>
>>> The YT video is 3 years old, yet the website isn't finished or very
>>> helpful - something tells me this didn't get very far...
>>>
>>>
>>> A
>>>
>>> On 4 Jul 2026, at 02:43, Benjam?n Velasco via Synth-diy <
>>> synth-diy at synth-diy.org> wrote:
>>>
>>> I recently noticed this Arp Prosoloist clone:
>>>
>>> https://www.grpsynthesizer.it/index.php/en/products/grp-vintage-genesi.html
>>>
>>> Does anyone know anything about it? Is it a part by part clone (sans
>>> keyboard)? How does it compare to the original? I'm curious about the
>>> implementation of the VCO since the one in the Prosoloist/Pro DGX is
>>> quite unique.
>>>
>>> I've sent a couple of emails to the company with no answer.
>>>
>>> Cheers
>>>
>>> --
>>> *Benjam?n Velasco Ossand?n*
>>> Cel. +56 9 96344468
>>> Casa. +56 2 27162400
>>> Oficina. +56 2 29254154
>>> ________________________________________________________
>>> 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
>>>
>>>
>>>
>>
>> --
>> *Benjam?n Velasco Ossand?n*
>> Cel. +56 9 96344468
>> Casa. +56 2 27162400
>> Oficina. +56 2 29254154
>> ________________________________________________________
>> 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
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260703/22f0c8c0/attachment.htm>

From cheater00social at gmail.com  Sat Jul  4 11:25:14 2026
From: cheater00social at gmail.com (cheater cheater)
Date: Sat, 4 Jul 2026 11:25:14 +0200
Subject: [sdiy] Converting rack mount to DC input?
Message-ID: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>

Hi all,
Beside my head I have my mic processing rack with a bunch of preamps,
voice strips, EQs, etc. I'm in a very quiet room, and the transformer
buzz is audible, which is undesirable for my kind of work. I've been
wondering if anyone ever tried converting their analog racks to DC
input, and how that went. All the racks I'm talking about are
internally running at +15,0,-15V rails, so I could just have a single
linear (or even high quality SMPS) power supply, distribute it via XT
or XLR style connectors, and have simple filter boards inside each
unit that filter the incoming DC, with switch to disconnect the mains
PSU and connect the DC board. I was wondering if this is a good idea
in general and in particular how this relates to issues like ground
loops and EMI pickup. My run from the DC power supply to the rack
would be about 2-3 meters long, but it would be running parallel to
some digital cabling. I would also be interested in suggestions on
connectors to use, especially if I want to make daisy chain cables
that go from device to device.

I would appreciate suggestions / experiences on the topic.

Thanks!

From mbryant at futurehorizons.com  Sat Jul  4 11:36:27 2026
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Sat, 4 Jul 2026 09:36:27 +0000
Subject: [sdiy] Converting rack mount to DC input?
In-Reply-To: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
References: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
Message-ID: <CWLP265MB7132ACD53F64DF5D188BC6D1DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

Yes this is a well known problem, and older top-end professional mixers with linear power supplies always put the power supply in a remote box.

Here is a typical one :  https://www.ebay.co.uk/itm/257443162756

As well as thick wires for the supplies and ground, they also had return wires so that the PSU compensated for any voltage loss in the cable, which was often tens of metres long.  I've even seen them dumped in the studio's reception to keep the receptionist warm ?

I think the CPS-150 was the smallest we did, but there will be equivalent small external PSUs from Midas and so on.
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of cheater cheater via Synth-diy <synth-diy at synth-diy.org>
Sent: 04 July 2026 10:25
To: synth-diy <synth-diy at synth-diy.org>
Subject: [sdiy] Converting rack mount to DC input?

Hi all,
Beside my head I have my mic processing rack with a bunch of preamps,
voice strips, EQs, etc. I'm in a very quiet room, and the transformer
buzz is audible, which is undesirable for my kind of work. I've been
wondering if anyone ever tried converting their analog racks to DC
input, and how that went. All the racks I'm talking about are
internally running at +15,0,-15V rails, so I could just have a single
linear (or even high quality SMPS) power supply, distribute it via XT
or XLR style connectors, and have simple filter boards inside each
unit that filter the incoming DC, with switch to disconnect the mains
PSU and connect the DC board. I was wondering if this is a good idea
in general and in particular how this relates to issues like ground
loops and EMI pickup. My run from the DC power supply to the rack
would be about 2-3 meters long, but it would be running parallel to
some digital cabling. I would also be interested in suggestions on
connectors to use, especially if I want to make daisy chain cables
that go from device to device.

I would appreciate suggestions / experiences on the topic.

Thanks!
________________________________________________________
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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260704/72597d41/attachment.htm>

From mbryant at futurehorizons.com  Sat Jul  4 11:37:30 2026
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Sat, 4 Jul 2026 09:37:30 +0000
Subject: [sdiy] GRP Genesi
In-Reply-To: <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
 <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
Message-ID: <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

Do you have a link to the patent ?  I found an interesting article about the feedback counters but it wasn't detailed enough to say exactly how it worked.
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Michael E Caloroso via Synth-diy <synth-diy at synth-diy.org>
Sent: 04 July 2026 04:45
To: Benjam?n Velasco <guatis at gmail.com>
Cc: SYNTH DIY <synth-diy at synth-diy.org>
Subject: Re: [sdiy] GRP Genesi

Yes the VCO in the ProSoloist/DGX is often misunderstood as digital, it is actually analog.  The patent explains it much better.  Definitely unique and very very stable.

MC

On Fri, Jul 3, 2026 at 11:42?PM Michael E Caloroso <mec.forumreader at gmail.com<mailto:mec.forumreader at gmail.com>> wrote:
One was on display at Superbooth 2026.  A german magazine (Synmag) has a review in an upcoming issue.

MC

On Fri, Jul 3, 2026 at 6:29?PM Benjam?n Velasco via Synth-diy <synth-diy at synth-diy.org<mailto:synth-diy at synth-diy.org>> wrote:
I became aware of these when recently some units started popping on Ebay, Reverb, etc....Maybe leftovers? I'm intrigued...

El vie, 3 jul 2026 a las 18:19, Adam (synthDIY) (<synthdiy at adambaby.com<mailto:synthdiy at adambaby.com>>) escribi?:
The YT video is 3 years old, yet the website isn't finished or very helpful - something tells me this didn't get very far...


A

On 4 Jul 2026, at 02:43, Benjam?n Velasco via Synth-diy <synth-diy at synth-diy.org<mailto:synth-diy at synth-diy.org>> wrote:

I recently noticed this Arp Prosoloist clone:
https://www.grpsynthesizer.it/index.php/en/products/grp-vintage-genesi.html

Does anyone know anything about it? Is it a part by part clone (sans keyboard)? How does it compare to the original? I'm curious about the implementation of the VCO since the one in the Prosoloist/Pro DGX is quite unique.

I've sent a couple of emails to the company with no answer.

Cheers

--
Benjam?n Velasco Ossand?n
Cel. +56 9 96344468
Casa. +56 2 27162400
Oficina. +56 2 29254154
________________________________________________________
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>



--
Benjam?n Velasco Ossand?n
Cel. +56 9 96344468
Casa. +56 2 27162400
Oficina. +56 2 29254154
________________________________________________________
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>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260704/e0a44e22/attachment.htm>

From cheater00social at gmail.com  Sat Jul  4 11:44:02 2026
From: cheater00social at gmail.com (cheater cheater)
Date: Sat, 4 Jul 2026 11:44:02 +0200
Subject: [sdiy] Converting rack mount to DC input?
In-Reply-To: <CWLP265MB7132ACD53F64DF5D188BC6D1DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
 <CWLP265MB7132ACD53F64DF5D188BC6D1DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <CAGn5V--MxBdBsp8__najLgpEbxmvqdVH4Q7vVuxO9MyO2n2wGQ@mail.gmail.com>

Thanks Mike. Do you think sharing one large PSU across many rack items
will be fine? I mean the whole stack currently takes less than 100W
mains. My guess would be to short the kelvin sensing pins to the rails
where I get close to the first rack item and then just distribute the
three rails (+V, -V, 0) without any sense wires.

On Sat, Jul 4, 2026 at 11:36?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
>
> Yes this is a well known problem, and older top-end professional mixers with linear power supplies always put the power supply in a remote box.
>
> Here is a typical one :  https://www.ebay.co.uk/itm/257443162756
>
> As well as thick wires for the supplies and ground, they also had return wires so that the PSU compensated for any voltage loss in the cable, which was often tens of metres long.  I've even seen them dumped in the studio's reception to keep the receptionist warm ?
>
> I think the CPS-150 was the smallest we did, but there will be equivalent small external PSUs from Midas and so on.
> ________________________________
> From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of cheater cheater via Synth-diy <synth-diy at synth-diy.org>
> Sent: 04 July 2026 10:25
> To: synth-diy <synth-diy at synth-diy.org>
> Subject: [sdiy] Converting rack mount to DC input?
>
> Hi all,
> Beside my head I have my mic processing rack with a bunch of preamps,
> voice strips, EQs, etc. I'm in a very quiet room, and the transformer
> buzz is audible, which is undesirable for my kind of work. I've been
> wondering if anyone ever tried converting their analog racks to DC
> input, and how that went. All the racks I'm talking about are
> internally running at +15,0,-15V rails, so I could just have a single
> linear (or even high quality SMPS) power supply, distribute it via XT
> or XLR style connectors, and have simple filter boards inside each
> unit that filter the incoming DC, with switch to disconnect the mains
> PSU and connect the DC board. I was wondering if this is a good idea
> in general and in particular how this relates to issues like ground
> loops and EMI pickup. My run from the DC power supply to the rack
> would be about 2-3 meters long, but it would be running parallel to
> some digital cabling. I would also be interested in suggestions on
> connectors to use, especially if I want to make daisy chain cables
> that go from device to device.
>
> I would appreciate suggestions / experiences on the topic.
>
> Thanks!
> ________________________________________________________
> 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 mbryant at futurehorizons.com  Sat Jul  4 11:48:32 2026
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Sat, 4 Jul 2026 09:48:32 +0000
Subject: [sdiy] Converting rack mount to DC input?
In-Reply-To: <CAGn5V--MxBdBsp8__najLgpEbxmvqdVH4Q7vVuxO9MyO2n2wGQ@mail.gmail.com>
References: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
 <CWLP265MB7132ACD53F64DF5D188BC6D1DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V--MxBdBsp8__najLgpEbxmvqdVH4Q7vVuxO9MyO2n2wGQ@mail.gmail.com>
Message-ID: <CWLP265MB7132A32EFAA23F11BAAFA0CDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

Yes that would be fine - it's effectively what happens in a large mixer.  It's a long way from one end to the other of a 48 channel analogue console ?

They are also designed so you can put two in parallel so providing fail-safe operation for live use.  Being out in the middle of a concert hall mixing can be a precarious place to be when the sound dies, but you probably don't need that ?

You'll also find the power line noise on these units is probably better than your present supplies.
________________________________
From: cheater cheater <cheater00social at gmail.com>
Sent: 04 July 2026 10:44
To: Mike Bryant <mbryant at futurehorizons.com>
Cc: synth-diy <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Converting rack mount to DC input?

Thanks Mike. Do you think sharing one large PSU across many rack items
will be fine? I mean the whole stack currently takes less than 100W
mains. My guess would be to short the kelvin sensing pins to the rails
where I get close to the first rack item and then just distribute the
three rails (+V, -V, 0) without any sense wires.

On Sat, Jul 4, 2026 at 11:36?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
>
> Yes this is a well known problem, and older top-end professional mixers with linear power supplies always put the power supply in a remote box.
>
> Here is a typical one :  https://www.ebay.co.uk/itm/257443162756
>
> As well as thick wires for the supplies and ground, they also had return wires so that the PSU compensated for any voltage loss in the cable, which was often tens of metres long.  I've even seen them dumped in the studio's reception to keep the receptionist warm ?
>
> I think the CPS-150 was the smallest we did, but there will be equivalent small external PSUs from Midas and so on.
> ________________________________
> From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of cheater cheater via Synth-diy <synth-diy at synth-diy.org>
> Sent: 04 July 2026 10:25
> To: synth-diy <synth-diy at synth-diy.org>
> Subject: [sdiy] Converting rack mount to DC input?
>
> Hi all,
> Beside my head I have my mic processing rack with a bunch of preamps,
> voice strips, EQs, etc. I'm in a very quiet room, and the transformer
> buzz is audible, which is undesirable for my kind of work. I've been
> wondering if anyone ever tried converting their analog racks to DC
> input, and how that went. All the racks I'm talking about are
> internally running at +15,0,-15V rails, so I could just have a single
> linear (or even high quality SMPS) power supply, distribute it via XT
> or XLR style connectors, and have simple filter boards inside each
> unit that filter the incoming DC, with switch to disconnect the mains
> PSU and connect the DC board. I was wondering if this is a good idea
> in general and in particular how this relates to issues like ground
> loops and EMI pickup. My run from the DC power supply to the rack
> would be about 2-3 meters long, but it would be running parallel to
> some digital cabling. I would also be interested in suggestions on
> connectors to use, especially if I want to make daisy chain cables
> that go from device to device.
>
> I would appreciate suggestions / experiences on the topic.
>
> Thanks!
> ________________________________________________________
> 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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260704/1047b14f/attachment.htm>

From mbryant at futurehorizons.com  Sat Jul  4 12:59:13 2026
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Sat, 4 Jul 2026 10:59:13 +0000
Subject: [sdiy] Converting rack mount to DC input?
In-Reply-To: <CAGn5V-_PFfmu2bnagGbG6bZdyTzaScWMz3_8oQ0RSKK+VdJYhQ@mail.gmail.com>
References: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
 <CWLP265MB7132ACD53F64DF5D188BC6D1DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V--MxBdBsp8__najLgpEbxmvqdVH4Q7vVuxO9MyO2n2wGQ@mail.gmail.com>
 <CWLP265MB7132A32EFAA23F11BAAFA0CDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-_PFfmu2bnagGbG6bZdyTzaScWMz3_8oQ0RSKK+VdJYhQ@mail.gmail.com>
Message-ID: <CWLP265MB71325B17A5DE406B11A5CD0EDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

They usually have an adjuster so you can set them back to 15V.

No idea on second-tier brands ?

Yes 950 is back-breaking - needs to be on wheels.  Not what you need.

________________________________
From: cheater cheater <cheater00social at gmail.com>
Sent: 04 July 2026 11:03
To: Mike Bryant <mbryant at futurehorizons.com>
Cc: synth-diy <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Converting rack mount to DC input?

That's cool & interesting!

Two questions

1. The rack units (mostly dbx / behringer stuff since those go real
cheap nowadays for a lot of function) use 15V rails. The CPS 950 you
linked to provides 17V rails. What would I do?

2. Could you suggest power supplies for other mixer brands if you have
any suggestions please? Soundcraft are just a little difficult to find
here.

Jeez that CPS-950 is a hog :)

Oh, it reminds me I might probably need the 48V too. Good call...

On Sat, Jul 4, 2026 at 11:48?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
>
> Yes that would be fine - it's effectively what happens in a large mixer.  It's a long way from one end to the other of a 48 channel analogue console ?
>
> They are also designed so you can put two in parallel so providing fail-safe operation for live use.  Being out in the middle of a concert hall mixing can be a precarious place to be when the sound dies, but you probably don't need that ?
>
> You'll also find the power line noise on these units is probably better than your present supplies.
> ________________________________
> From: cheater cheater <cheater00social at gmail.com>
> Sent: 04 July 2026 10:44
> To: Mike Bryant <mbryant at futurehorizons.com>
> Cc: synth-diy <synth-diy at synth-diy.org>
> Subject: Re: [sdiy] Converting rack mount to DC input?
>
> Thanks Mike. Do you think sharing one large PSU across many rack items
> will be fine? I mean the whole stack currently takes less than 100W
> mains. My guess would be to short the kelvin sensing pins to the rails
> where I get close to the first rack item and then just distribute the
> three rails (+V, -V, 0) without any sense wires.
>
> On Sat, Jul 4, 2026 at 11:36?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
> >
> > Yes this is a well known problem, and older top-end professional mixers with linear power supplies always put the power supply in a remote box.
> >
> > Here is a typical one :  https://www.ebay.co.uk/itm/257443162756
> >
> > As well as thick wires for the supplies and ground, they also had return wires so that the PSU compensated for any voltage loss in the cable, which was often tens of metres long.  I've even seen them dumped in the studio's reception to keep the receptionist warm ?
> >
> > I think the CPS-150 was the smallest we did, but there will be equivalent small external PSUs from Midas and so on.
> > ________________________________
> > From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of cheater cheater via Synth-diy <synth-diy at synth-diy.org>
> > Sent: 04 July 2026 10:25
> > To: synth-diy <synth-diy at synth-diy.org>
> > Subject: [sdiy] Converting rack mount to DC input?
> >
> > Hi all,
> > Beside my head I have my mic processing rack with a bunch of preamps,
> > voice strips, EQs, etc. I'm in a very quiet room, and the transformer
> > buzz is audible, which is undesirable for my kind of work. I've been
> > wondering if anyone ever tried converting their analog racks to DC
> > input, and how that went. All the racks I'm talking about are
> > internally running at +15,0,-15V rails, so I could just have a single
> > linear (or even high quality SMPS) power supply, distribute it via XT
> > or XLR style connectors, and have simple filter boards inside each
> > unit that filter the incoming DC, with switch to disconnect the mains
> > PSU and connect the DC board. I was wondering if this is a good idea
> > in general and in particular how this relates to issues like ground
> > loops and EMI pickup. My run from the DC power supply to the rack
> > would be about 2-3 meters long, but it would be running parallel to
> > some digital cabling. I would also be interested in suggestions on
> > connectors to use, especially if I want to make daisy chain cables
> > that go from device to device.
> >
> > I would appreciate suggestions / experiences on the topic.
> >
> > Thanks!
> > ________________________________________________________
> > 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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260704/33dcd447/attachment.htm>

From cheater00social at gmail.com  Sat Jul  4 13:23:57 2026
From: cheater00social at gmail.com (cheater cheater)
Date: Sat, 4 Jul 2026 13:23:57 +0200
Subject: [sdiy] Converting rack mount to DC input?
In-Reply-To: <CWLP265MB71325B17A5DE406B11A5CD0EDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
 <CWLP265MB7132ACD53F64DF5D188BC6D1DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V--MxBdBsp8__najLgpEbxmvqdVH4Q7vVuxO9MyO2n2wGQ@mail.gmail.com>
 <CWLP265MB7132A32EFAA23F11BAAFA0CDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-_PFfmu2bnagGbG6bZdyTzaScWMz3_8oQ0RSKK+VdJYhQ@mail.gmail.com>
 <CWLP265MB71325B17A5DE406B11A5CD0EDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <CAGn5V-8-Zi1wNniLPo3yO4yCrFMPff+Su=GGk10pdQH43uq7rQ@mail.gmail.com>

Heh, ok!

A few more questions if you feel like it:
1. Is the CPS 150 still as low noise / rejection as the larger ones? I
think I have one of those in storage somewhere actually, now that I
think about it!
2. The 150 doesn't seem to have sensing pins in its output cable - do
you know what the smallest one is that does?
3. Do you think the separate circuits of the rack devices might couple
to each other via the power rails, producing crosstalk between them?

Thanks...

On Sat, Jul 4, 2026 at 12:59?PM Mike Bryant <mbryant at futurehorizons.com> wrote:
>
> They usually have an adjuster so you can set them back to 15V.
>
> No idea on second-tier brands ?
>
> Yes 950 is back-breaking - needs to be on wheels.  Not what you need.
>
> ________________________________
> From: cheater cheater <cheater00social at gmail.com>
> Sent: 04 July 2026 11:03
> To: Mike Bryant <mbryant at futurehorizons.com>
> Cc: synth-diy <synth-diy at synth-diy.org>
> Subject: Re: [sdiy] Converting rack mount to DC input?
>
> That's cool & interesting!
>
> Two questions
>
> 1. The rack units (mostly dbx / behringer stuff since those go real
> cheap nowadays for a lot of function) use 15V rails. The CPS 950 you
> linked to provides 17V rails. What would I do?
>
> 2. Could you suggest power supplies for other mixer brands if you have
> any suggestions please? Soundcraft are just a little difficult to find
> here.
>
> Jeez that CPS-950 is a hog :)
>
> Oh, it reminds me I might probably need the 48V too. Good call...
>
> On Sat, Jul 4, 2026 at 11:48?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
> >
> > Yes that would be fine - it's effectively what happens in a large mixer.  It's a long way from one end to the other of a 48 channel analogue console ?
> >
> > They are also designed so you can put two in parallel so providing fail-safe operation for live use.  Being out in the middle of a concert hall mixing can be a precarious place to be when the sound dies, but you probably don't need that ?
> >
> > You'll also find the power line noise on these units is probably better than your present supplies.
> > ________________________________
> > From: cheater cheater <cheater00social at gmail.com>
> > Sent: 04 July 2026 10:44
> > To: Mike Bryant <mbryant at futurehorizons.com>
> > Cc: synth-diy <synth-diy at synth-diy.org>
> > Subject: Re: [sdiy] Converting rack mount to DC input?
> >
> > Thanks Mike. Do you think sharing one large PSU across many rack items
> > will be fine? I mean the whole stack currently takes less than 100W
> > mains. My guess would be to short the kelvin sensing pins to the rails
> > where I get close to the first rack item and then just distribute the
> > three rails (+V, -V, 0) without any sense wires.
> >
> > On Sat, Jul 4, 2026 at 11:36?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
> > >
> > > Yes this is a well known problem, and older top-end professional mixers with linear power supplies always put the power supply in a remote box.
> > >
> > > Here is a typical one :  https://www.ebay.co.uk/itm/257443162756
> > >
> > > As well as thick wires for the supplies and ground, they also had return wires so that the PSU compensated for any voltage loss in the cable, which was often tens of metres long.  I've even seen them dumped in the studio's reception to keep the receptionist warm ?
> > >
> > > I think the CPS-150 was the smallest we did, but there will be equivalent small external PSUs from Midas and so on.
> > > ________________________________
> > > From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of cheater cheater via Synth-diy <synth-diy at synth-diy.org>
> > > Sent: 04 July 2026 10:25
> > > To: synth-diy <synth-diy at synth-diy.org>
> > > Subject: [sdiy] Converting rack mount to DC input?
> > >
> > > Hi all,
> > > Beside my head I have my mic processing rack with a bunch of preamps,
> > > voice strips, EQs, etc. I'm in a very quiet room, and the transformer
> > > buzz is audible, which is undesirable for my kind of work. I've been
> > > wondering if anyone ever tried converting their analog racks to DC
> > > input, and how that went. All the racks I'm talking about are
> > > internally running at +15,0,-15V rails, so I could just have a single
> > > linear (or even high quality SMPS) power supply, distribute it via XT
> > > or XLR style connectors, and have simple filter boards inside each
> > > unit that filter the incoming DC, with switch to disconnect the mains
> > > PSU and connect the DC board. I was wondering if this is a good idea
> > > in general and in particular how this relates to issues like ground
> > > loops and EMI pickup. My run from the DC power supply to the rack
> > > would be about 2-3 meters long, but it would be running parallel to
> > > some digital cabling. I would also be interested in suggestions on
> > > connectors to use, especially if I want to make daisy chain cables
> > > that go from device to device.
> > >
> > > I would appreciate suggestions / experiences on the topic.
> > >
> > > Thanks!
> > > ________________________________________________________
> > > 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 mbryant at futurehorizons.com  Sat Jul  4 13:41:21 2026
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Sat, 4 Jul 2026 11:41:21 +0000
Subject: [sdiy] Converting rack mount to DC input?
In-Reply-To: <CAGn5V-8-Zi1wNniLPo3yO4yCrFMPff+Su=GGk10pdQH43uq7rQ@mail.gmail.com>
References: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
 <CWLP265MB7132ACD53F64DF5D188BC6D1DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V--MxBdBsp8__najLgpEbxmvqdVH4Q7vVuxO9MyO2n2wGQ@mail.gmail.com>
 <CWLP265MB7132A32EFAA23F11BAAFA0CDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-_PFfmu2bnagGbG6bZdyTzaScWMz3_8oQ0RSKK+VdJYhQ@mail.gmail.com>
 <CWLP265MB71325B17A5DE406B11A5CD0EDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-8-Zi1wNniLPo3yO4yCrFMPff+Su=GGk10pdQH43uq7rQ@mail.gmail.com>
Message-ID: <CWLP265MB7132EDF286AAF3C212DBA0BDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

Sorry yes you're correct, the CPS150 is a much simpler PSU than the others.  But I'm sure it will still be more than good enough for what you are doing.

As for crosstalk between devices, that usually happens through the ground lead, not the +/- leads.  So make sure everything is earthed as much as possible.

________________________________
From: cheater cheater <cheater00social at gmail.com>
Sent: 04 July 2026 12:23
To: Mike Bryant <mbryant at futurehorizons.com>
Cc: synth-diy <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Converting rack mount to DC input?

Heh, ok!

A few more questions if you feel like it:
1. Is the CPS 150 still as low noise / rejection as the larger ones? I
think I have one of those in storage somewhere actually, now that I
think about it!
2. The 150 doesn't seem to have sensing pins in its output cable - do
you know what the smallest one is that does?
3. Do you think the separate circuits of the rack devices might couple
to each other via the power rails, producing crosstalk between them?

Thanks...

On Sat, Jul 4, 2026 at 12:59?PM Mike Bryant <mbryant at futurehorizons.com> wrote:
>
> They usually have an adjuster so you can set them back to 15V.
>
> No idea on second-tier brands ?
>
> Yes 950 is back-breaking - needs to be on wheels.  Not what you need.
>
> ________________________________
> From: cheater cheater <cheater00social at gmail.com>
> Sent: 04 July 2026 11:03
> To: Mike Bryant <mbryant at futurehorizons.com>
> Cc: synth-diy <synth-diy at synth-diy.org>
> Subject: Re: [sdiy] Converting rack mount to DC input?
>
> That's cool & interesting!
>
> Two questions
>
> 1. The rack units (mostly dbx / behringer stuff since those go real
> cheap nowadays for a lot of function) use 15V rails. The CPS 950 you
> linked to provides 17V rails. What would I do?
>
> 2. Could you suggest power supplies for other mixer brands if you have
> any suggestions please? Soundcraft are just a little difficult to find
> here.
>
> Jeez that CPS-950 is a hog :)
>
> Oh, it reminds me I might probably need the 48V too. Good call...
>
> On Sat, Jul 4, 2026 at 11:48?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
> >
> > Yes that would be fine - it's effectively what happens in a large mixer.  It's a long way from one end to the other of a 48 channel analogue console ?
> >
> > They are also designed so you can put two in parallel so providing fail-safe operation for live use.  Being out in the middle of a concert hall mixing can be a precarious place to be when the sound dies, but you probably don't need that ?
> >
> > You'll also find the power line noise on these units is probably better than your present supplies.
> > ________________________________
> > From: cheater cheater <cheater00social at gmail.com>
> > Sent: 04 July 2026 10:44
> > To: Mike Bryant <mbryant at futurehorizons.com>
> > Cc: synth-diy <synth-diy at synth-diy.org>
> > Subject: Re: [sdiy] Converting rack mount to DC input?
> >
> > Thanks Mike. Do you think sharing one large PSU across many rack items
> > will be fine? I mean the whole stack currently takes less than 100W
> > mains. My guess would be to short the kelvin sensing pins to the rails
> > where I get close to the first rack item and then just distribute the
> > three rails (+V, -V, 0) without any sense wires.
> >
> > On Sat, Jul 4, 2026 at 11:36?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
> > >
> > > Yes this is a well known problem, and older top-end professional mixers with linear power supplies always put the power supply in a remote box.
> > >
> > > Here is a typical one :  https://www.ebay.co.uk/itm/257443162756
> > >
> > > As well as thick wires for the supplies and ground, they also had return wires so that the PSU compensated for any voltage loss in the cable, which was often tens of metres long.  I've even seen them dumped in the studio's reception to keep the receptionist warm ?
> > >
> > > I think the CPS-150 was the smallest we did, but there will be equivalent small external PSUs from Midas and so on.
> > > ________________________________
> > > From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of cheater cheater via Synth-diy <synth-diy at synth-diy.org>
> > > Sent: 04 July 2026 10:25
> > > To: synth-diy <synth-diy at synth-diy.org>
> > > Subject: [sdiy] Converting rack mount to DC input?
> > >
> > > Hi all,
> > > Beside my head I have my mic processing rack with a bunch of preamps,
> > > voice strips, EQs, etc. I'm in a very quiet room, and the transformer
> > > buzz is audible, which is undesirable for my kind of work. I've been
> > > wondering if anyone ever tried converting their analog racks to DC
> > > input, and how that went. All the racks I'm talking about are
> > > internally running at +15,0,-15V rails, so I could just have a single
> > > linear (or even high quality SMPS) power supply, distribute it via XT
> > > or XLR style connectors, and have simple filter boards inside each
> > > unit that filter the incoming DC, with switch to disconnect the mains
> > > PSU and connect the DC board. I was wondering if this is a good idea
> > > in general and in particular how this relates to issues like ground
> > > loops and EMI pickup. My run from the DC power supply to the rack
> > > would be about 2-3 meters long, but it would be running parallel to
> > > some digital cabling. I would also be interested in suggestions on
> > > connectors to use, especially if I want to make daisy chain cables
> > > that go from device to device.
> > >
> > > I would appreciate suggestions / experiences on the topic.
> > >
> > > Thanks!
> > > ________________________________________________________
> > > 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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260704/c8e16fea/attachment.htm>

From cheater00social at gmail.com  Sat Jul  4 13:56:52 2026
From: cheater00social at gmail.com (cheater cheater)
Date: Sat, 4 Jul 2026 13:56:52 +0200
Subject: [sdiy] Converting rack mount to DC input?
In-Reply-To: <CWLP265MB7132EDF286AAF3C212DBA0BDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
 <CWLP265MB7132ACD53F64DF5D188BC6D1DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V--MxBdBsp8__najLgpEbxmvqdVH4Q7vVuxO9MyO2n2wGQ@mail.gmail.com>
 <CWLP265MB7132A32EFAA23F11BAAFA0CDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-_PFfmu2bnagGbG6bZdyTzaScWMz3_8oQ0RSKK+VdJYhQ@mail.gmail.com>
 <CWLP265MB71325B17A5DE406B11A5CD0EDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-8-Zi1wNniLPo3yO4yCrFMPff+Su=GGk10pdQH43uq7rQ@mail.gmail.com>
 <CWLP265MB7132EDF286AAF3C212DBA0BDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <CAGn5V-_-sZ87+3b3FVPkDWeRnQi3YhnbbNoXPiNm_FNLBtr1VQ@mail.gmail.com>

Would I separately earth the chassis of each rack device to mains PE,
or would I just rely on the power supply 0V as grounding?

Thanks...

On Sat, Jul 4, 2026 at 1:41?PM Mike Bryant <mbryant at futurehorizons.com> wrote:
>
> Sorry yes you're correct, the CPS150 is a much simpler PSU than the others.  But I'm sure it will still be more than good enough for what you are doing.
>
> As for crosstalk between devices, that usually happens through the ground lead, not the +/- leads.  So make sure everything is earthed as much as possible.
>
> ________________________________
> From: cheater cheater <cheater00social at gmail.com>
> Sent: 04 July 2026 12:23
> To: Mike Bryant <mbryant at futurehorizons.com>
> Cc: synth-diy <synth-diy at synth-diy.org>
> Subject: Re: [sdiy] Converting rack mount to DC input?
>
> Heh, ok!
>
> A few more questions if you feel like it:
> 1. Is the CPS 150 still as low noise / rejection as the larger ones? I
> think I have one of those in storage somewhere actually, now that I
> think about it!
> 2. The 150 doesn't seem to have sensing pins in its output cable - do
> you know what the smallest one is that does?
> 3. Do you think the separate circuits of the rack devices might couple
> to each other via the power rails, producing crosstalk between them?
>
> Thanks...
>
> On Sat, Jul 4, 2026 at 12:59?PM Mike Bryant <mbryant at futurehorizons.com> wrote:
> >
> > They usually have an adjuster so you can set them back to 15V.
> >
> > No idea on second-tier brands ?
> >
> > Yes 950 is back-breaking - needs to be on wheels.  Not what you need.
> >
> > ________________________________
> > From: cheater cheater <cheater00social at gmail.com>
> > Sent: 04 July 2026 11:03
> > To: Mike Bryant <mbryant at futurehorizons.com>
> > Cc: synth-diy <synth-diy at synth-diy.org>
> > Subject: Re: [sdiy] Converting rack mount to DC input?
> >
> > That's cool & interesting!
> >
> > Two questions
> >
> > 1. The rack units (mostly dbx / behringer stuff since those go real
> > cheap nowadays for a lot of function) use 15V rails. The CPS 950 you
> > linked to provides 17V rails. What would I do?
> >
> > 2. Could you suggest power supplies for other mixer brands if you have
> > any suggestions please? Soundcraft are just a little difficult to find
> > here.
> >
> > Jeez that CPS-950 is a hog :)
> >
> > Oh, it reminds me I might probably need the 48V too. Good call...
> >
> > On Sat, Jul 4, 2026 at 11:48?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
> > >
> > > Yes that would be fine - it's effectively what happens in a large mixer.  It's a long way from one end to the other of a 48 channel analogue console ?
> > >
> > > They are also designed so you can put two in parallel so providing fail-safe operation for live use.  Being out in the middle of a concert hall mixing can be a precarious place to be when the sound dies, but you probably don't need that ?
> > >
> > > You'll also find the power line noise on these units is probably better than your present supplies.
> > > ________________________________
> > > From: cheater cheater <cheater00social at gmail.com>
> > > Sent: 04 July 2026 10:44
> > > To: Mike Bryant <mbryant at futurehorizons.com>
> > > Cc: synth-diy <synth-diy at synth-diy.org>
> > > Subject: Re: [sdiy] Converting rack mount to DC input?
> > >
> > > Thanks Mike. Do you think sharing one large PSU across many rack items
> > > will be fine? I mean the whole stack currently takes less than 100W
> > > mains. My guess would be to short the kelvin sensing pins to the rails
> > > where I get close to the first rack item and then just distribute the
> > > three rails (+V, -V, 0) without any sense wires.
> > >
> > > On Sat, Jul 4, 2026 at 11:36?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
> > > >
> > > > Yes this is a well known problem, and older top-end professional mixers with linear power supplies always put the power supply in a remote box.
> > > >
> > > > Here is a typical one :  https://www.ebay.co.uk/itm/257443162756
> > > >
> > > > As well as thick wires for the supplies and ground, they also had return wires so that the PSU compensated for any voltage loss in the cable, which was often tens of metres long.  I've even seen them dumped in the studio's reception to keep the receptionist warm ?
> > > >
> > > > I think the CPS-150 was the smallest we did, but there will be equivalent small external PSUs from Midas and so on.
> > > > ________________________________
> > > > From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of cheater cheater via Synth-diy <synth-diy at synth-diy.org>
> > > > Sent: 04 July 2026 10:25
> > > > To: synth-diy <synth-diy at synth-diy.org>
> > > > Subject: [sdiy] Converting rack mount to DC input?
> > > >
> > > > Hi all,
> > > > Beside my head I have my mic processing rack with a bunch of preamps,
> > > > voice strips, EQs, etc. I'm in a very quiet room, and the transformer
> > > > buzz is audible, which is undesirable for my kind of work. I've been
> > > > wondering if anyone ever tried converting their analog racks to DC
> > > > input, and how that went. All the racks I'm talking about are
> > > > internally running at +15,0,-15V rails, so I could just have a single
> > > > linear (or even high quality SMPS) power supply, distribute it via XT
> > > > or XLR style connectors, and have simple filter boards inside each
> > > > unit that filter the incoming DC, with switch to disconnect the mains
> > > > PSU and connect the DC board. I was wondering if this is a good idea
> > > > in general and in particular how this relates to issues like ground
> > > > loops and EMI pickup. My run from the DC power supply to the rack
> > > > would be about 2-3 meters long, but it would be running parallel to
> > > > some digital cabling. I would also be interested in suggestions on
> > > > connectors to use, especially if I want to make daisy chain cables
> > > > that go from device to device.
> > > >
> > > > I would appreciate suggestions / experiences on the topic.
> > > >
> > > > Thanks!
> > > > ________________________________________________________
> > > > 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 fanwander at mnet-online.de  Sat Jul  4 14:22:19 2026
From: fanwander at mnet-online.de (Florian Anwander)
Date: Sat, 4 Jul 2026 14:22:19 +0200
Subject: [sdiy] Converting rack mount to DC input?
In-Reply-To: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
References: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
Message-ID: <63165836-a201-4cc3-9a3c-5a2f2b2226f5@mnet-online.de>

Maybe, it's a stupid thought, but...: could it be that a device relies 
on beeing galvanical separated from other devices. I this case the 
common supply might clash with the devices concept.


Am 04.07.26 um 11:25 schrieb cheater cheater via Synth-diy:
> Hi all,
> Beside my head I have my mic processing rack with a bunch of preamps,
> voice strips, EQs, etc. I'm in a very quiet room, and the transformer
> buzz is audible, which is undesirable for my kind of work. I've been
> wondering if anyone ever tried converting their analog racks to DC
> input, and how that went. All the racks I'm talking about are
> internally running at +15,0,-15V rails, so I could just have a single
> linear (or even high quality SMPS) power supply, distribute it via XT
> or XLR style connectors, and have simple filter boards inside each
> unit that filter the incoming DC, with switch to disconnect the mains
> PSU and connect the DC board. I was wondering if this is a good idea
> in general and in particular how this relates to issues like ground
> loops and EMI pickup. My run from the DC power supply to the rack
> would be about 2-3 meters long, but it would be running parallel to
> some digital cabling. I would also be interested in suggestions on
> connectors to use, especially if I want to make daisy chain cables
> that go from device to device.
>
> I would appreciate suggestions / experiences on the topic.
>
> Thanks!
> ________________________________________________________
> 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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260704/ff69d2da/attachment.htm>

From mbryant at futurehorizons.com  Sat Jul  4 15:17:08 2026
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Sat, 4 Jul 2026 13:17:08 +0000
Subject: [sdiy] Converting rack mount to DC input?
In-Reply-To: <CAGn5V-_-sZ87+3b3FVPkDWeRnQi3YhnbbNoXPiNm_FNLBtr1VQ@mail.gmail.com>
References: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
 <CWLP265MB7132ACD53F64DF5D188BC6D1DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V--MxBdBsp8__najLgpEbxmvqdVH4Q7vVuxO9MyO2n2wGQ@mail.gmail.com>
 <CWLP265MB7132A32EFAA23F11BAAFA0CDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-_PFfmu2bnagGbG6bZdyTzaScWMz3_8oQ0RSKK+VdJYhQ@mail.gmail.com>
 <CWLP265MB71325B17A5DE406B11A5CD0EDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-8-Zi1wNniLPo3yO4yCrFMPff+Su=GGk10pdQH43uq7rQ@mail.gmail.com>
 <CWLP265MB7132EDF286AAF3C212DBA0BDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-_-sZ87+3b3FVPkDWeRnQi3YhnbbNoXPiNm_FNLBtr1VQ@mail.gmail.com>
Message-ID: <CWLP265MB7132A00C2814F483FF6D5365DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

Power supply ground is normally pretty hefty.

But if you use one of those modern switchers with just L and N then you need to route ground separately.

The gospel :
https://www.ranecommercial.com/legacy/library.html

Wiring, Interconnection and Grounding section.




________________________________
From: cheater cheater <cheater00social at gmail.com>
Sent: 04 July 2026 12:56
To: Mike Bryant <mbryant at futurehorizons.com>
Cc: synth-diy <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Converting rack mount to DC input?

Would I separately earth the chassis of each rack device to mains PE,
or would I just rely on the power supply 0V as grounding?

Thanks...

On Sat, Jul 4, 2026 at 1:41?PM Mike Bryant <mbryant at futurehorizons.com> wrote:
>
> Sorry yes you're correct, the CPS150 is a much simpler PSU than the others.  But I'm sure it will still be more than good enough for what you are doing.
>
> As for crosstalk between devices, that usually happens through the ground lead, not the +/- leads.  So make sure everything is earthed as much as possible.
>
> ________________________________
> From: cheater cheater <cheater00social at gmail.com>
> Sent: 04 July 2026 12:23
> To: Mike Bryant <mbryant at futurehorizons.com>
> Cc: synth-diy <synth-diy at synth-diy.org>
> Subject: Re: [sdiy] Converting rack mount to DC input?
>
> Heh, ok!
>
> A few more questions if you feel like it:
> 1. Is the CPS 150 still as low noise / rejection as the larger ones? I
> think I have one of those in storage somewhere actually, now that I
> think about it!
> 2. The 150 doesn't seem to have sensing pins in its output cable - do
> you know what the smallest one is that does?
> 3. Do you think the separate circuits of the rack devices might couple
> to each other via the power rails, producing crosstalk between them?
>
> Thanks...
>
> On Sat, Jul 4, 2026 at 12:59?PM Mike Bryant <mbryant at futurehorizons.com> wrote:
> >
> > They usually have an adjuster so you can set them back to 15V.
> >
> > No idea on second-tier brands ?
> >
> > Yes 950 is back-breaking - needs to be on wheels.  Not what you need.
> >
> > ________________________________
> > From: cheater cheater <cheater00social at gmail.com>
> > Sent: 04 July 2026 11:03
> > To: Mike Bryant <mbryant at futurehorizons.com>
> > Cc: synth-diy <synth-diy at synth-diy.org>
> > Subject: Re: [sdiy] Converting rack mount to DC input?
> >
> > That's cool & interesting!
> >
> > Two questions
> >
> > 1. The rack units (mostly dbx / behringer stuff since those go real
> > cheap nowadays for a lot of function) use 15V rails. The CPS 950 you
> > linked to provides 17V rails. What would I do?
> >
> > 2. Could you suggest power supplies for other mixer brands if you have
> > any suggestions please? Soundcraft are just a little difficult to find
> > here.
> >
> > Jeez that CPS-950 is a hog :)
> >
> > Oh, it reminds me I might probably need the 48V too. Good call...
> >
> > On Sat, Jul 4, 2026 at 11:48?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
> > >
> > > Yes that would be fine - it's effectively what happens in a large mixer.  It's a long way from one end to the other of a 48 channel analogue console ?
> > >
> > > They are also designed so you can put two in parallel so providing fail-safe operation for live use.  Being out in the middle of a concert hall mixing can be a precarious place to be when the sound dies, but you probably don't need that ?
> > >
> > > You'll also find the power line noise on these units is probably better than your present supplies.
> > > ________________________________
> > > From: cheater cheater <cheater00social at gmail.com>
> > > Sent: 04 July 2026 10:44
> > > To: Mike Bryant <mbryant at futurehorizons.com>
> > > Cc: synth-diy <synth-diy at synth-diy.org>
> > > Subject: Re: [sdiy] Converting rack mount to DC input?
> > >
> > > Thanks Mike. Do you think sharing one large PSU across many rack items
> > > will be fine? I mean the whole stack currently takes less than 100W
> > > mains. My guess would be to short the kelvin sensing pins to the rails
> > > where I get close to the first rack item and then just distribute the
> > > three rails (+V, -V, 0) without any sense wires.
> > >
> > > On Sat, Jul 4, 2026 at 11:36?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
> > > >
> > > > Yes this is a well known problem, and older top-end professional mixers with linear power supplies always put the power supply in a remote box.
> > > >
> > > > Here is a typical one :  https://www.ebay.co.uk/itm/257443162756
> > > >
> > > > As well as thick wires for the supplies and ground, they also had return wires so that the PSU compensated for any voltage loss in the cable, which was often tens of metres long.  I've even seen them dumped in the studio's reception to keep the receptionist warm ?
> > > >
> > > > I think the CPS-150 was the smallest we did, but there will be equivalent small external PSUs from Midas and so on.
> > > > ________________________________
> > > > From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of cheater cheater via Synth-diy <synth-diy at synth-diy.org>
> > > > Sent: 04 July 2026 10:25
> > > > To: synth-diy <synth-diy at synth-diy.org>
> > > > Subject: [sdiy] Converting rack mount to DC input?
> > > >
> > > > Hi all,
> > > > Beside my head I have my mic processing rack with a bunch of preamps,
> > > > voice strips, EQs, etc. I'm in a very quiet room, and the transformer
> > > > buzz is audible, which is undesirable for my kind of work. I've been
> > > > wondering if anyone ever tried converting their analog racks to DC
> > > > input, and how that went. All the racks I'm talking about are
> > > > internally running at +15,0,-15V rails, so I could just have a single
> > > > linear (or even high quality SMPS) power supply, distribute it via XT
> > > > or XLR style connectors, and have simple filter boards inside each
> > > > unit that filter the incoming DC, with switch to disconnect the mains
> > > > PSU and connect the DC board. I was wondering if this is a good idea
> > > > in general and in particular how this relates to issues like ground
> > > > loops and EMI pickup. My run from the DC power supply to the rack
> > > > would be about 2-3 meters long, but it would be running parallel to
> > > > some digital cabling. I would also be interested in suggestions on
> > > > connectors to use, especially if I want to make daisy chain cables
> > > > that go from device to device.
> > > >
> > > > I would appreciate suggestions / experiences on the topic.
> > > >
> > > > Thanks!
> > > > ________________________________________________________
> > > > 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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260704/eeb29680/attachment.htm>

From cheater00social at gmail.com  Sat Jul  4 15:51:09 2026
From: cheater00social at gmail.com (cheater cheater)
Date: Sat, 4 Jul 2026 15:51:09 +0200
Subject: [sdiy] Converting rack mount to DC input?
In-Reply-To: <63165836-a201-4cc3-9a3c-5a2f2b2226f5@mnet-online.de>
References: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
 <63165836-a201-4cc3-9a3c-5a2f2b2226f5@mnet-online.de>
Message-ID: <CAGn5V--7GtzuE6wNs1g5ROZk+bhyvG3tNqCPpswxagJM-Db9-A@mail.gmail.com>

On Sat, Jul 4, 2026 at 2:28?PM Florian Anwander via Synth-diy
<synth-diy at synth-diy.org> wrote:
>
> Maybe, it's a stupid thought, but...: could it be that a device relies on beeing galvanical separated from other devices. I this case the common supply might clash with the devices concept.

Wouldn't that require input and output transformers too? (none of my
equipment has those)

>
> Am 04.07.26 um 11:25 schrieb cheater cheater via Synth-diy:
>
> Hi all,
> Beside my head I have my mic processing rack with a bunch of preamps,
> voice strips, EQs, etc. I'm in a very quiet room, and the transformer
> buzz is audible, which is undesirable for my kind of work. I've been
> wondering if anyone ever tried converting their analog racks to DC
> input, and how that went. All the racks I'm talking about are
> internally running at +15,0,-15V rails, so I could just have a single
> linear (or even high quality SMPS) power supply, distribute it via XT
> or XLR style connectors, and have simple filter boards inside each
> unit that filter the incoming DC, with switch to disconnect the mains
> PSU and connect the DC board. I was wondering if this is a good idea
> in general and in particular how this relates to issues like ground
> loops and EMI pickup. My run from the DC power supply to the rack
> would be about 2-3 meters long, but it would be running parallel to
> some digital cabling. I would also be interested in suggestions on
> connectors to use, especially if I want to make daisy chain cables
> that go from device to device.
>
> I would appreciate suggestions / experiences on the topic.
>
> Thanks!
> ________________________________________________________
> 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 cheater00social at gmail.com  Sat Jul  4 15:54:43 2026
From: cheater00social at gmail.com (cheater cheater)
Date: Sat, 4 Jul 2026 15:54:43 +0200
Subject: [sdiy] Converting rack mount to DC input?
In-Reply-To: <CWLP265MB7132A00C2814F483FF6D5365DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
 <CWLP265MB7132ACD53F64DF5D188BC6D1DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V--MxBdBsp8__najLgpEbxmvqdVH4Q7vVuxO9MyO2n2wGQ@mail.gmail.com>
 <CWLP265MB7132A32EFAA23F11BAAFA0CDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-_PFfmu2bnagGbG6bZdyTzaScWMz3_8oQ0RSKK+VdJYhQ@mail.gmail.com>
 <CWLP265MB71325B17A5DE406B11A5CD0EDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-8-Zi1wNniLPo3yO4yCrFMPff+Su=GGk10pdQH43uq7rQ@mail.gmail.com>
 <CWLP265MB7132EDF286AAF3C212DBA0BDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-_-sZ87+3b3FVPkDWeRnQi3YhnbbNoXPiNm_FNLBtr1VQ@mail.gmail.com>
 <CWLP265MB7132A00C2814F483FF6D5365DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <CAGn5V-9JHq3QhTy4xuHq2u5iLjfHA3aFUihvwwtOE8Wio=+dJw@mail.gmail.com>

On Sat, Jul 4, 2026 at 3:17?PM Mike Bryant <mbryant at futurehorizons.com> wrote:
>
> Power supply ground is normally pretty hefty.
>
> But if you use one of those modern switchers with just L and N then you need to route ground separately.
>
> The gospel :
> https://www.ranecommercial.com/legacy/library.html
>
> Wiring, Interconnection and Grounding section.

Oh, yeah, definitely.

I was just wondering:

- If I have a linear PSU with -15, 0, 15V
- and the 0V is earth referenced (i.e. shorted to mains protective earth)
- and the rails (-15 and +15V) have kelvin leads

THEN
is it fine to just ground the devices via the 0V
OR
should I also earth those devices directly to mains PE via an IEC
cable that only has the PE lead and no L/N lead?

>
>
>
> ________________________________
> From: cheater cheater <cheater00social at gmail.com>
> Sent: 04 July 2026 12:56
> To: Mike Bryant <mbryant at futurehorizons.com>
> Cc: synth-diy <synth-diy at synth-diy.org>
> Subject: Re: [sdiy] Converting rack mount to DC input?
>
> Would I separately earth the chassis of each rack device to mains PE,
> or would I just rely on the power supply 0V as grounding?
>
> Thanks...
>
> On Sat, Jul 4, 2026 at 1:41?PM Mike Bryant <mbryant at futurehorizons.com> wrote:
> >
> > Sorry yes you're correct, the CPS150 is a much simpler PSU than the others.  But I'm sure it will still be more than good enough for what you are doing.
> >
> > As for crosstalk between devices, that usually happens through the ground lead, not the +/- leads.  So make sure everything is earthed as much as possible.
> >
> > ________________________________
> > From: cheater cheater <cheater00social at gmail.com>
> > Sent: 04 July 2026 12:23
> > To: Mike Bryant <mbryant at futurehorizons.com>
> > Cc: synth-diy <synth-diy at synth-diy.org>
> > Subject: Re: [sdiy] Converting rack mount to DC input?
> >
> > Heh, ok!
> >
> > A few more questions if you feel like it:
> > 1. Is the CPS 150 still as low noise / rejection as the larger ones? I
> > think I have one of those in storage somewhere actually, now that I
> > think about it!
> > 2. The 150 doesn't seem to have sensing pins in its output cable - do
> > you know what the smallest one is that does?
> > 3. Do you think the separate circuits of the rack devices might couple
> > to each other via the power rails, producing crosstalk between them?
> >
> > Thanks...
> >
> > On Sat, Jul 4, 2026 at 12:59?PM Mike Bryant <mbryant at futurehorizons.com> wrote:
> > >
> > > They usually have an adjuster so you can set them back to 15V.
> > >
> > > No idea on second-tier brands ?
> > >
> > > Yes 950 is back-breaking - needs to be on wheels.  Not what you need.
> > >
> > > ________________________________
> > > From: cheater cheater <cheater00social at gmail.com>
> > > Sent: 04 July 2026 11:03
> > > To: Mike Bryant <mbryant at futurehorizons.com>
> > > Cc: synth-diy <synth-diy at synth-diy.org>
> > > Subject: Re: [sdiy] Converting rack mount to DC input?
> > >
> > > That's cool & interesting!
> > >
> > > Two questions
> > >
> > > 1. The rack units (mostly dbx / behringer stuff since those go real
> > > cheap nowadays for a lot of function) use 15V rails. The CPS 950 you
> > > linked to provides 17V rails. What would I do?
> > >
> > > 2. Could you suggest power supplies for other mixer brands if you have
> > > any suggestions please? Soundcraft are just a little difficult to find
> > > here.
> > >
> > > Jeez that CPS-950 is a hog :)
> > >
> > > Oh, it reminds me I might probably need the 48V too. Good call...
> > >
> > > On Sat, Jul 4, 2026 at 11:48?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
> > > >
> > > > Yes that would be fine - it's effectively what happens in a large mixer.  It's a long way from one end to the other of a 48 channel analogue console ?
> > > >
> > > > They are also designed so you can put two in parallel so providing fail-safe operation for live use.  Being out in the middle of a concert hall mixing can be a precarious place to be when the sound dies, but you probably don't need that ?
> > > >
> > > > You'll also find the power line noise on these units is probably better than your present supplies.
> > > > ________________________________
> > > > From: cheater cheater <cheater00social at gmail.com>
> > > > Sent: 04 July 2026 10:44
> > > > To: Mike Bryant <mbryant at futurehorizons.com>
> > > > Cc: synth-diy <synth-diy at synth-diy.org>
> > > > Subject: Re: [sdiy] Converting rack mount to DC input?
> > > >
> > > > Thanks Mike. Do you think sharing one large PSU across many rack items
> > > > will be fine? I mean the whole stack currently takes less than 100W
> > > > mains. My guess would be to short the kelvin sensing pins to the rails
> > > > where I get close to the first rack item and then just distribute the
> > > > three rails (+V, -V, 0) without any sense wires.
> > > >
> > > > On Sat, Jul 4, 2026 at 11:36?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
> > > > >
> > > > > Yes this is a well known problem, and older top-end professional mixers with linear power supplies always put the power supply in a remote box.
> > > > >
> > > > > Here is a typical one :  https://www.ebay.co.uk/itm/257443162756
> > > > >
> > > > > As well as thick wires for the supplies and ground, they also had return wires so that the PSU compensated for any voltage loss in the cable, which was often tens of metres long.  I've even seen them dumped in the studio's reception to keep the receptionist warm ?
> > > > >
> > > > > I think the CPS-150 was the smallest we did, but there will be equivalent small external PSUs from Midas and so on.
> > > > > ________________________________
> > > > > From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of cheater cheater via Synth-diy <synth-diy at synth-diy.org>
> > > > > Sent: 04 July 2026 10:25
> > > > > To: synth-diy <synth-diy at synth-diy.org>
> > > > > Subject: [sdiy] Converting rack mount to DC input?
> > > > >
> > > > > Hi all,
> > > > > Beside my head I have my mic processing rack with a bunch of preamps,
> > > > > voice strips, EQs, etc. I'm in a very quiet room, and the transformer
> > > > > buzz is audible, which is undesirable for my kind of work. I've been
> > > > > wondering if anyone ever tried converting their analog racks to DC
> > > > > input, and how that went. All the racks I'm talking about are
> > > > > internally running at +15,0,-15V rails, so I could just have a single
> > > > > linear (or even high quality SMPS) power supply, distribute it via XT
> > > > > or XLR style connectors, and have simple filter boards inside each
> > > > > unit that filter the incoming DC, with switch to disconnect the mains
> > > > > PSU and connect the DC board. I was wondering if this is a good idea
> > > > > in general and in particular how this relates to issues like ground
> > > > > loops and EMI pickup. My run from the DC power supply to the rack
> > > > > would be about 2-3 meters long, but it would be running parallel to
> > > > > some digital cabling. I would also be interested in suggestions on
> > > > > connectors to use, especially if I want to make daisy chain cables
> > > > > that go from device to device.
> > > > >
> > > > > I would appreciate suggestions / experiences on the topic.
> > > > >
> > > > > Thanks!
> > > > > ________________________________________________________
> > > > > 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 mbryant at futurehorizons.com  Sat Jul  4 16:36:20 2026
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Sat, 4 Jul 2026 14:36:20 +0000
Subject: [sdiy] Converting rack mount to DC input?
In-Reply-To: <CAGn5V-9JHq3QhTy4xuHq2u5iLjfHA3aFUihvwwtOE8Wio=+dJw@mail.gmail.com>
References: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
 <CWLP265MB7132ACD53F64DF5D188BC6D1DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V--MxBdBsp8__najLgpEbxmvqdVH4Q7vVuxO9MyO2n2wGQ@mail.gmail.com>
 <CWLP265MB7132A32EFAA23F11BAAFA0CDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-_PFfmu2bnagGbG6bZdyTzaScWMz3_8oQ0RSKK+VdJYhQ@mail.gmail.com>
 <CWLP265MB71325B17A5DE406B11A5CD0EDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-8-Zi1wNniLPo3yO4yCrFMPff+Su=GGk10pdQH43uq7rQ@mail.gmail.com>
 <CWLP265MB7132EDF286AAF3C212DBA0BDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-_-sZ87+3b3FVPkDWeRnQi3YhnbbNoXPiNm_FNLBtr1VQ@mail.gmail.com>
 <CWLP265MB7132A00C2814F483FF6D5365DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-9JHq3QhTy4xuHq2u5iLjfHA3aFUihvwwtOE8Wio=+dJw@mail.gmail.com>
Message-ID: <CWLP265MB7132E7B93A7BF2A3331B400CDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

You now come down to national rules and what your set up is.

In the UK, all permanently installed bare metalwork racks (e.g. effects racks or Eurorack synth racks) have to be permanently hardwire connected to mains ground, not just via an IEC.  Large studios usually have a ground distribution screw-block on most walls.  But that doesn't mean the effects units or synth modules in those racks have to be grounded through the metal rack.

And of course many racks are moveable so provided they are grounded via the IEC providing L and N that should suffice.

________________________________
- If I have a linear PSU with -15, 0, 15V
- and the 0V is earth referenced (i.e. shorted to mains protective earth)
- and the rails (-15 and +15V) have kelvin leads

THEN
is it fine to just ground the devices via the 0V
OR
should I also earth those devices directly to mains PE via an IEC
cable that only has the PE lead and no L/N lead?

>
>
>
> ________________________________
> From: cheater cheater <cheater00social at gmail.com>
> Sent: 04 July 2026 12:56
> To: Mike Bryant <mbryant at futurehorizons.com>
> Cc: synth-diy <synth-diy at synth-diy.org>
> Subject: Re: [sdiy] Converting rack mount to DC input?
>
> Would I separately earth the chassis of each rack device to mains PE,
> or would I just rely on the power supply 0V as grounding?
>
> Thanks...
>
> On Sat, Jul 4, 2026 at 1:41?PM Mike Bryant <mbryant at futurehorizons.com> wrote:
> >
> > Sorry yes you're correct, the CPS150 is a much simpler PSU than the others.  But I'm sure it will still be more than good enough for what you are doing.
> >
> > As for crosstalk between devices, that usually happens through the ground lead, not the +/- leads.  So make sure everything is earthed as much as possible.
> >
> > ________________________________
> > From: cheater cheater <cheater00social at gmail.com>
> > Sent: 04 July 2026 12:23
> > To: Mike Bryant <mbryant at futurehorizons.com>
> > Cc: synth-diy <synth-diy at synth-diy.org>
> > Subject: Re: [sdiy] Converting rack mount to DC input?
> >
> > Heh, ok!
> >
> > A few more questions if you feel like it:
> > 1. Is the CPS 150 still as low noise / rejection as the larger ones? I
> > think I have one of those in storage somewhere actually, now that I
> > think about it!
> > 2. The 150 doesn't seem to have sensing pins in its output cable - do
> > you know what the smallest one is that does?
> > 3. Do you think the separate circuits of the rack devices might couple
> > to each other via the power rails, producing crosstalk between them?
> >
> > Thanks...
> >
> > On Sat, Jul 4, 2026 at 12:59?PM Mike Bryant <mbryant at futurehorizons.com> wrote:
> > >
> > > They usually have an adjuster so you can set them back to 15V.
> > >
> > > No idea on second-tier brands ?
> > >
> > > Yes 950 is back-breaking - needs to be on wheels.  Not what you need.
> > >
> > > ________________________________
> > > From: cheater cheater <cheater00social at gmail.com>
> > > Sent: 04 July 2026 11:03
> > > To: Mike Bryant <mbryant at futurehorizons.com>
> > > Cc: synth-diy <synth-diy at synth-diy.org>
> > > Subject: Re: [sdiy] Converting rack mount to DC input?
> > >
> > > That's cool & interesting!
> > >
> > > Two questions
> > >
> > > 1. The rack units (mostly dbx / behringer stuff since those go real
> > > cheap nowadays for a lot of function) use 15V rails. The CPS 950 you
> > > linked to provides 17V rails. What would I do?
> > >
> > > 2. Could you suggest power supplies for other mixer brands if you have
> > > any suggestions please? Soundcraft are just a little difficult to find
> > > here.
> > >
> > > Jeez that CPS-950 is a hog :)
> > >
> > > Oh, it reminds me I might probably need the 48V too. Good call...
> > >
> > > On Sat, Jul 4, 2026 at 11:48?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
> > > >
> > > > Yes that would be fine - it's effectively what happens in a large mixer.  It's a long way from one end to the other of a 48 channel analogue console ?
> > > >
> > > > They are also designed so you can put two in parallel so providing fail-safe operation for live use.  Being out in the middle of a concert hall mixing can be a precarious place to be when the sound dies, but you probably don't need that ?
> > > >
> > > > You'll also find the power line noise on these units is probably better than your present supplies.
> > > > ________________________________
> > > > From: cheater cheater <cheater00social at gmail.com>
> > > > Sent: 04 July 2026 10:44
> > > > To: Mike Bryant <mbryant at futurehorizons.com>
> > > > Cc: synth-diy <synth-diy at synth-diy.org>
> > > > Subject: Re: [sdiy] Converting rack mount to DC input?
> > > >
> > > > Thanks Mike. Do you think sharing one large PSU across many rack items
> > > > will be fine? I mean the whole stack currently takes less than 100W
> > > > mains. My guess would be to short the kelvin sensing pins to the rails
> > > > where I get close to the first rack item and then just distribute the
> > > > three rails (+V, -V, 0) without any sense wires.
> > > >
> > > > On Sat, Jul 4, 2026 at 11:36?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
> > > > >
> > > > > Yes this is a well known problem, and older top-end professional mixers with linear power supplies always put the power supply in a remote box.
> > > > >
> > > > > Here is a typical one :  https://www.ebay.co.uk/itm/257443162756
> > > > >
> > > > > As well as thick wires for the supplies and ground, they also had return wires so that the PSU compensated for any voltage loss in the cable, which was often tens of metres long.  I've even seen them dumped in the studio's reception to keep the receptionist warm ?
> > > > >
> > > > > I think the CPS-150 was the smallest we did, but there will be equivalent small external PSUs from Midas and so on.
> > > > > ________________________________
> > > > > From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of cheater cheater via Synth-diy <synth-diy at synth-diy.org>
> > > > > Sent: 04 July 2026 10:25
> > > > > To: synth-diy <synth-diy at synth-diy.org>
> > > > > Subject: [sdiy] Converting rack mount to DC input?
> > > > >
> > > > > Hi all,
> > > > > Beside my head I have my mic processing rack with a bunch of preamps,
> > > > > voice strips, EQs, etc. I'm in a very quiet room, and the transformer
> > > > > buzz is audible, which is undesirable for my kind of work. I've been
> > > > > wondering if anyone ever tried converting their analog racks to DC
> > > > > input, and how that went. All the racks I'm talking about are
> > > > > internally running at +15,0,-15V rails, so I could just have a single
> > > > > linear (or even high quality SMPS) power supply, distribute it via XT
> > > > > or XLR style connectors, and have simple filter boards inside each
> > > > > unit that filter the incoming DC, with switch to disconnect the mains
> > > > > PSU and connect the DC board. I was wondering if this is a good idea
> > > > > in general and in particular how this relates to issues like ground
> > > > > loops and EMI pickup. My run from the DC power supply to the rack
> > > > > would be about 2-3 meters long, but it would be running parallel to
> > > > > some digital cabling. I would also be interested in suggestions on
> > > > > connectors to use, especially if I want to make daisy chain cables
> > > > > that go from device to device.
> > > > >
> > > > > I would appreciate suggestions / experiences on the topic.
> > > > >
> > > > > Thanks!
> > > > > ________________________________________________________
> > > > > 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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260704/40ee21eb/attachment.htm>

From cheater00social at gmail.com  Sat Jul  4 17:38:26 2026
From: cheater00social at gmail.com (cheater cheater)
Date: Sat, 4 Jul 2026 17:38:26 +0200
Subject: [sdiy] Converting rack mount to DC input?
In-Reply-To: <CWLP265MB7132E7B93A7BF2A3331B400CDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
 <CWLP265MB7132ACD53F64DF5D188BC6D1DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V--MxBdBsp8__najLgpEbxmvqdVH4Q7vVuxO9MyO2n2wGQ@mail.gmail.com>
 <CWLP265MB7132A32EFAA23F11BAAFA0CDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-_PFfmu2bnagGbG6bZdyTzaScWMz3_8oQ0RSKK+VdJYhQ@mail.gmail.com>
 <CWLP265MB71325B17A5DE406B11A5CD0EDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-8-Zi1wNniLPo3yO4yCrFMPff+Su=GGk10pdQH43uq7rQ@mail.gmail.com>
 <CWLP265MB7132EDF286AAF3C212DBA0BDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-_-sZ87+3b3FVPkDWeRnQi3YhnbbNoXPiNm_FNLBtr1VQ@mail.gmail.com>
 <CWLP265MB7132A00C2814F483FF6D5365DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-9JHq3QhTy4xuHq2u5iLjfHA3aFUihvwwtOE8Wio=+dJw@mail.gmail.com>
 <CWLP265MB7132E7B93A7BF2A3331B400CDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <CAGn5V-9gby+Vk0u_2Zx-=3emGya89mLCws33KC5-nb2OL95zag@mail.gmail.com>

oh, i'm not concerned with like national rules or whatever, just
what's good for audio :)

On Sat, Jul 4, 2026 at 4:36?PM Mike Bryant <mbryant at futurehorizons.com> wrote:
>
> You now come down to national rules and what your set up is.
>
> In the UK, all permanently installed bare metalwork racks (e.g. effects racks or Eurorack synth racks) have to be permanently hardwire connected to mains ground, not just via an IEC.  Large studios usually have a ground distribution screw-block on most walls.  But that doesn't mean the effects units or synth modules in those racks have to be grounded through the metal rack.
>
> And of course many racks are moveable so provided they are grounded via the IEC providing L and N that should suffice.
>
> ________________________________
> - If I have a linear PSU with -15, 0, 15V
> - and the 0V is earth referenced (i.e. shorted to mains protective earth)
> - and the rails (-15 and +15V) have kelvin leads
>
> THEN
> is it fine to just ground the devices via the 0V
> OR
> should I also earth those devices directly to mains PE via an IEC
> cable that only has the PE lead and no L/N lead?
>
> >
> >
> >
> > ________________________________
> > From: cheater cheater <cheater00social at gmail.com>
> > Sent: 04 July 2026 12:56
> > To: Mike Bryant <mbryant at futurehorizons.com>
> > Cc: synth-diy <synth-diy at synth-diy.org>
> > Subject: Re: [sdiy] Converting rack mount to DC input?
> >
> > Would I separately earth the chassis of each rack device to mains PE,
> > or would I just rely on the power supply 0V as grounding?
> >
> > Thanks...
> >
> > On Sat, Jul 4, 2026 at 1:41?PM Mike Bryant <mbryant at futurehorizons.com> wrote:
> > >
> > > Sorry yes you're correct, the CPS150 is a much simpler PSU than the others.  But I'm sure it will still be more than good enough for what you are doing.
> > >
> > > As for crosstalk between devices, that usually happens through the ground lead, not the +/- leads.  So make sure everything is earthed as much as possible.
> > >
> > > ________________________________
> > > From: cheater cheater <cheater00social at gmail.com>
> > > Sent: 04 July 2026 12:23
> > > To: Mike Bryant <mbryant at futurehorizons.com>
> > > Cc: synth-diy <synth-diy at synth-diy.org>
> > > Subject: Re: [sdiy] Converting rack mount to DC input?
> > >
> > > Heh, ok!
> > >
> > > A few more questions if you feel like it:
> > > 1. Is the CPS 150 still as low noise / rejection as the larger ones? I
> > > think I have one of those in storage somewhere actually, now that I
> > > think about it!
> > > 2. The 150 doesn't seem to have sensing pins in its output cable - do
> > > you know what the smallest one is that does?
> > > 3. Do you think the separate circuits of the rack devices might couple
> > > to each other via the power rails, producing crosstalk between them?
> > >
> > > Thanks...
> > >
> > > On Sat, Jul 4, 2026 at 12:59?PM Mike Bryant <mbryant at futurehorizons.com> wrote:
> > > >
> > > > They usually have an adjuster so you can set them back to 15V.
> > > >
> > > > No idea on second-tier brands ?
> > > >
> > > > Yes 950 is back-breaking - needs to be on wheels.  Not what you need.
> > > >
> > > > ________________________________
> > > > From: cheater cheater <cheater00social at gmail.com>
> > > > Sent: 04 July 2026 11:03
> > > > To: Mike Bryant <mbryant at futurehorizons.com>
> > > > Cc: synth-diy <synth-diy at synth-diy.org>
> > > > Subject: Re: [sdiy] Converting rack mount to DC input?
> > > >
> > > > That's cool & interesting!
> > > >
> > > > Two questions
> > > >
> > > > 1. The rack units (mostly dbx / behringer stuff since those go real
> > > > cheap nowadays for a lot of function) use 15V rails. The CPS 950 you
> > > > linked to provides 17V rails. What would I do?
> > > >
> > > > 2. Could you suggest power supplies for other mixer brands if you have
> > > > any suggestions please? Soundcraft are just a little difficult to find
> > > > here.
> > > >
> > > > Jeez that CPS-950 is a hog :)
> > > >
> > > > Oh, it reminds me I might probably need the 48V too. Good call...
> > > >
> > > > On Sat, Jul 4, 2026 at 11:48?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
> > > > >
> > > > > Yes that would be fine - it's effectively what happens in a large mixer.  It's a long way from one end to the other of a 48 channel analogue console ?
> > > > >
> > > > > They are also designed so you can put two in parallel so providing fail-safe operation for live use.  Being out in the middle of a concert hall mixing can be a precarious place to be when the sound dies, but you probably don't need that ?
> > > > >
> > > > > You'll also find the power line noise on these units is probably better than your present supplies.
> > > > > ________________________________
> > > > > From: cheater cheater <cheater00social at gmail.com>
> > > > > Sent: 04 July 2026 10:44
> > > > > To: Mike Bryant <mbryant at futurehorizons.com>
> > > > > Cc: synth-diy <synth-diy at synth-diy.org>
> > > > > Subject: Re: [sdiy] Converting rack mount to DC input?
> > > > >
> > > > > Thanks Mike. Do you think sharing one large PSU across many rack items
> > > > > will be fine? I mean the whole stack currently takes less than 100W
> > > > > mains. My guess would be to short the kelvin sensing pins to the rails
> > > > > where I get close to the first rack item and then just distribute the
> > > > > three rails (+V, -V, 0) without any sense wires.
> > > > >
> > > > > On Sat, Jul 4, 2026 at 11:36?AM Mike Bryant <mbryant at futurehorizons.com> wrote:
> > > > > >
> > > > > > Yes this is a well known problem, and older top-end professional mixers with linear power supplies always put the power supply in a remote box.
> > > > > >
> > > > > > Here is a typical one :  https://www.ebay.co.uk/itm/257443162756
> > > > > >
> > > > > > As well as thick wires for the supplies and ground, they also had return wires so that the PSU compensated for any voltage loss in the cable, which was often tens of metres long.  I've even seen them dumped in the studio's reception to keep the receptionist warm ?
> > > > > >
> > > > > > I think the CPS-150 was the smallest we did, but there will be equivalent small external PSUs from Midas and so on.
> > > > > > ________________________________
> > > > > > From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of cheater cheater via Synth-diy <synth-diy at synth-diy.org>
> > > > > > Sent: 04 July 2026 10:25
> > > > > > To: synth-diy <synth-diy at synth-diy.org>
> > > > > > Subject: [sdiy] Converting rack mount to DC input?
> > > > > >
> > > > > > Hi all,
> > > > > > Beside my head I have my mic processing rack with a bunch of preamps,
> > > > > > voice strips, EQs, etc. I'm in a very quiet room, and the transformer
> > > > > > buzz is audible, which is undesirable for my kind of work. I've been
> > > > > > wondering if anyone ever tried converting their analog racks to DC
> > > > > > input, and how that went. All the racks I'm talking about are
> > > > > > internally running at +15,0,-15V rails, so I could just have a single
> > > > > > linear (or even high quality SMPS) power supply, distribute it via XT
> > > > > > or XLR style connectors, and have simple filter boards inside each
> > > > > > unit that filter the incoming DC, with switch to disconnect the mains
> > > > > > PSU and connect the DC board. I was wondering if this is a good idea
> > > > > > in general and in particular how this relates to issues like ground
> > > > > > loops and EMI pickup. My run from the DC power supply to the rack
> > > > > > would be about 2-3 meters long, but it would be running parallel to
> > > > > > some digital cabling. I would also be interested in suggestions on
> > > > > > connectors to use, especially if I want to make daisy chain cables
> > > > > > that go from device to device.
> > > > > >
> > > > > > I would appreciate suggestions / experiences on the topic.
> > > > > >
> > > > > > Thanks!
> > > > > > ________________________________________________________
> > > > > > 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 mec.forumreader at gmail.com  Sat Jul  4 18:38:59 2026
From: mec.forumreader at gmail.com (Michael E Caloroso)
Date: Sat, 4 Jul 2026 12:38:59 -0400
Subject: [sdiy] GRP Genesi
In-Reply-To: <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
 <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
 <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <CAAv6=UBHa3YgE_EsWg00fdXkAB8Vc=D4BbV7636p+gXVPPoJ9Q@mail.gmail.com>

US 3,930,429

MC

On Sat, Jul 4, 2026 at 5:37?AM Mike Bryant <mbryant at futurehorizons.com>
wrote:

> Do you have a link to the patent ?  I found an interesting article about
> the feedback counters but it wasn't detailed enough to say exactly how it
> worked.
> ------------------------------
> *From:* Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Michael
> E Caloroso via Synth-diy <synth-diy at synth-diy.org>
> *Sent:* 04 July 2026 04:45
> *To:* Benjam?n Velasco <guatis at gmail.com>
> *Cc:* SYNTH DIY <synth-diy at synth-diy.org>
> *Subject:* Re: [sdiy] GRP Genesi
>
> Yes the VCO in the ProSoloist/DGX is often misunderstood as digital, it is
> actually analog.  The patent explains it much better.  Definitely unique
> and very very stable.
>
> MC
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260704/ec419d3f/attachment.htm>

From mr at analogue.org  Sat Jul  4 23:19:39 2026
From: mr at analogue.org (Mattias Rickardsson)
Date: Sat, 4 Jul 2026 23:19:39 +0200
Subject: [sdiy] Converting rack mount to DC input?
In-Reply-To: <63165836-a201-4cc3-9a3c-5a2f2b2226f5@mnet-online.de>
References: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
 <63165836-a201-4cc3-9a3c-5a2f2b2226f5@mnet-online.de>
Message-ID: <CAP92RBWx-2FkgpQROx+Jd-Zag5FtUnhL5zYu9Q3X6S5sDynq1g@mail.gmail.com>

Den l?r 4 juli 2026 14:23Florian Anwander via Synth-diy <
synth-diy at synth-diy.org> skrev:

> Maybe, it's a stupid thought, but...: could it be that a device relies on
> beeing galvanical separated from other devices. I this case the common
> supply might clash with the devices concept.
>

This reminds me of a somewhat similar issue I had many years ago:

I wanted a Korg MS-20 and a Korg KR-55 to share one external power puck.
(Swedish-sold old Korgs had a big external power transformer to step down
from 220 V AC to 16 V AC, which is then what the instrument then accepts
via a plug with 2 flat prongs that doesn't seem roadworthy with European
electrical standards.)

So I made a short splitter Y cable on the 16 V AC side and attached both
instruments and turned them on. But then I connected an audio cable between
them (or audio cables from both units to the same mixer) and I had a blown
fuse! It was apparently not okay to connect those two grounds together when
running off the same AC supply.

/mr

>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260704/4ca91da0/attachment.htm>

From neil.johnson71 at gmail.com  Sun Jul  5 11:26:43 2026
From: neil.johnson71 at gmail.com (Neil Johnson)
Date: Sun, 5 Jul 2026 10:26:43 +0100
Subject: [sdiy] GRP Genesi
In-Reply-To: <CAAv6=UBHa3YgE_EsWg00fdXkAB8Vc=D4BbV7636p+gXVPPoJ9Q@mail.gmail.com>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
 <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
 <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAAv6=UBHa3YgE_EsWg00fdXkAB8Vc=D4BbV7636p+gXVPPoJ9Q@mail.gmail.com>
Message-ID: <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>

Michael E Caloroso wrote:

> US 3,930,429
>

Don did a write-up of it here:
https://till.com/articles/arp/patents.html#US03930429
Very weird architecture indeed!

Neil
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260705/64502a54/attachment.htm>

From gordonjcp at gjcp.net  Sun Jul  5 15:39:14 2026
From: gordonjcp at gjcp.net (Gordonjcp)
Date: Sun, 5 Jul 2026 14:39:14 +0100
Subject: [sdiy] Converting rack mount to DC input?
In-Reply-To: <CAGn5V-9gby+Vk0u_2Zx-=3emGya89mLCws33KC5-nb2OL95zag@mail.gmail.com>
References: <CWLP265MB7132A32EFAA23F11BAAFA0CDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-_PFfmu2bnagGbG6bZdyTzaScWMz3_8oQ0RSKK+VdJYhQ@mail.gmail.com>
 <CWLP265MB71325B17A5DE406B11A5CD0EDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-8-Zi1wNniLPo3yO4yCrFMPff+Su=GGk10pdQH43uq7rQ@mail.gmail.com>
 <CWLP265MB7132EDF286AAF3C212DBA0BDDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-_-sZ87+3b3FVPkDWeRnQi3YhnbbNoXPiNm_FNLBtr1VQ@mail.gmail.com>
 <CWLP265MB7132A00C2814F483FF6D5365DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-9JHq3QhTy4xuHq2u5iLjfHA3aFUihvwwtOE8Wio=+dJw@mail.gmail.com>
 <CWLP265MB7132E7B93A7BF2A3331B400CDBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAGn5V-9gby+Vk0u_2Zx-=3emGya89mLCws33KC5-nb2OL95zag@mail.gmail.com>
Message-ID: <20260705133914.GA28814@gjcp.net>

On Sat, Jul 04, 2026 at 05:38:26PM +0200, cheater cheater via Synth-diy wrote:
> oh, i'm not concerned with like national rules or whatever, just
> what's good for audio :)

Your insurance company is, though ;-)

-- 
Gordonjcp


From mbryant at futurehorizons.com  Sun Jul  5 16:01:38 2026
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Sun, 5 Jul 2026 14:01:38 +0000
Subject: [sdiy] GRP Genesi
In-Reply-To: <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
 <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
 <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAAv6=UBHa3YgE_EsWg00fdXkAB8Vc=D4BbV7636p+gXVPPoJ9Q@mail.gmail.com>
 <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>
Message-ID: <CWLP265MB71320544D64A5F96310A2180DBF22@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

Does it really even need the linear to exp convertor ?  The feedback loop will force it to the correct frequency.  Portamento could just use a different charging function on the capacitor.

________________________________
From: Neil Johnson <neil.johnson71 at gmail.com>
Sent: 05 July 2026 10:26
To: Michael E Caloroso <mec.forumreader at gmail.com>
Cc: Mike Bryant <mbryant at futurehorizons.com>; SYNTH DIY <synth-diy at synth-diy.org>
Subject: Re: [sdiy] GRP Genesi

Michael E Caloroso wrote:
US 3,930,429

Don did a write-up of it here: https://till.com/articles/arp/patents.html#US03930429
Very weird architecture indeed!

Neil
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260705/1732aa92/attachment.htm>

From mec.forumreader at gmail.com  Sun Jul  5 20:57:09 2026
From: mec.forumreader at gmail.com (Michael E Caloroso)
Date: Sun, 5 Jul 2026 14:57:09 -0400
Subject: [sdiy] GRP Genesi
In-Reply-To: <CWLP265MB71320544D64A5F96310A2180DBF22@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
 <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
 <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAAv6=UBHa3YgE_EsWg00fdXkAB8Vc=D4BbV7636p+gXVPPoJ9Q@mail.gmail.com>
 <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>
 <CWLP265MB71320544D64A5F96310A2180DBF22@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <CAAv6=UBWX=s4c3t9PF2wtDSHgxBb48r_A23D+-F-gu5tv4JROQ@mail.gmail.com>

On the ProSoloist, a ten octave range is required for the VCO charged cap
core, which is not in the feedback loop.  You can't achieve that with a
v/hz architecture.  With a v/hz system, the control voltage doubles for
every octave and you quickly reach the power rail.  Thus the CV for top
pitch is defined just below the power rail (opamps back then were not
rail-to-rail opamps).

There's two problems with a v/hz system.  One, the pitch range is limited.
For a top pitch CV set at 14VDC, a ten octave range would have a descending
CV scale of 14V, 7V, 3.5V, 1.75V, 0.875V, 0.4375V, 0.21875V, 0.109375V, uh
oh.  We have a problem and have only reached eight octaves. The CVs for the
lower pitches descend into the inherent limitation of the opamp - the
microvolt error domain.  The offset error voltages are now a significant
contributor to the pitch CV, causing tuning problems that are impossible to
trim out because the errors drift with temperature.  So a realistic
range for a v/hz system is actually six octaves.

Problem two is modulation CV.  A fixed modulation CV will not produce the
same modulation depth across the entire range of a v/hz system.  If you
scale the gain of the modulation CV with pitch you run into another
problem; as the pitch CV ascends toward maximum pitch CV, the sum of pitch
and modulation CV must not exceed the maximum or you risk opamp latchup or
phase inversion.

That's why v/hz instruments - Moog Taurus I, Taurus III, Minitaur, Sirius,
Korg MS series, etc - have a limited pitch range.

So yes it does need the linear to expo converter for a v/oct system.  The
beauty of the PS VCO is that no tempco resistor is needed, although the
exponential DAC does require a custom resistor array of precision
non-standard values.

MC

On Sun, Jul 5, 2026 at 10:01?AM Mike Bryant <mbryant at futurehorizons.com>
wrote:

> Does it really even need the linear to exp convertor ?  The feedback loop
> will force it to the correct frequency.  Portamento could just use a
> different charging function on the capacitor.
>
> ------------------------------
> *From:* Neil Johnson <neil.johnson71 at gmail.com>
> *Sent:* 05 July 2026 10:26
> *To:* Michael E Caloroso <mec.forumreader at gmail.com>
> *Cc:* Mike Bryant <mbryant at futurehorizons.com>; SYNTH DIY <
> synth-diy at synth-diy.org>
> *Subject:* Re: [sdiy] GRP Genesi
>
> Michael E Caloroso wrote:
>
> US 3,930,429
>
>
> Don did a write-up of it here:
> https://till.com/articles/arp/patents.html#US03930429
> Very weird architecture indeed!
>
> Neil
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260705/defdac76/attachment.htm>

From mec.forumreader at gmail.com  Sun Jul  5 20:58:52 2026
From: mec.forumreader at gmail.com (Michael E Caloroso)
Date: Sun, 5 Jul 2026 14:58:52 -0400
Subject: [sdiy] GRP Genesi
In-Reply-To: <CWLP265MB71320544D64A5F96310A2180DBF22@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
 <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
 <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAAv6=UBHa3YgE_EsWg00fdXkAB8Vc=D4BbV7636p+gXVPPoJ9Q@mail.gmail.com>
 <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>
 <CWLP265MB71320544D64A5F96310A2180DBF22@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <CAAv6=UBnpuEOW52Sr4uPa1RmhtmM+Qzd6vbdh0o==wFD-utWMw@mail.gmail.com>

My error - the VCO charged cap core is inside the feedback loop.

It is indeed a weird architecture - Jeremy Hill was really thinking outside
the box!

MC

On Sun, Jul 5, 2026 at 10:01?AM Mike Bryant <mbryant at futurehorizons.com>
wrote:

> Does it really even need the linear to exp convertor ?  The feedback loop
> will force it to the correct frequency.  Portamento could just use a
> different charging function on the capacitor.
>
> ------------------------------
> *From:* Neil Johnson <neil.johnson71 at gmail.com>
> *Sent:* 05 July 2026 10:26
> *To:* Michael E Caloroso <mec.forumreader at gmail.com>
> *Cc:* Mike Bryant <mbryant at futurehorizons.com>; SYNTH DIY <
> synth-diy at synth-diy.org>
> *Subject:* Re: [sdiy] GRP Genesi
>
> Michael E Caloroso wrote:
>
> US 3,930,429
>
>
> Don did a write-up of it here:
> https://till.com/articles/arp/patents.html#US03930429
> Very weird architecture indeed!
>
> Neil
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260705/fad977ad/attachment.htm>

From spridley1 at gmail.com  Mon Jul  6 10:03:07 2026
From: spridley1 at gmail.com (S Ridley)
Date: Mon, 6 Jul 2026 09:03:07 +0100
Subject: [sdiy] GRP Genesi
In-Reply-To: <CAAv6=UBnpuEOW52Sr4uPa1RmhtmM+Qzd6vbdh0o==wFD-utWMw@mail.gmail.com>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
 <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
 <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAAv6=UBHa3YgE_EsWg00fdXkAB8Vc=D4BbV7636p+gXVPPoJ9Q@mail.gmail.com>
 <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>
 <CWLP265MB71320544D64A5F96310A2180DBF22@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAAv6=UBnpuEOW52Sr4uPa1RmhtmM+Qzd6vbdh0o==wFD-utWMw@mail.gmail.com>
Message-ID: <CAPgGCkJAxpmh-sb0NvuOcj2owxSWcGc5Bx+CTt7Wg9mm_4Uc9A@mail.gmail.com>

Jeremy Hill talks about designing the ARP Pro Soloist on namm org:

https://www.namm.org/library/oral-history/jeremy-hill


Steve


On Sun, 5 Jul 2026 at 20:03, Michael E Caloroso via Synth-diy <
synth-diy at synth-diy.org> wrote:

> My error - the VCO charged cap core is inside the feedback loop.
>
> It is indeed a weird architecture - Jeremy Hill was really thinking
> outside the box!
>
> MC
>
> On Sun, Jul 5, 2026 at 10:01?AM Mike Bryant <mbryant at futurehorizons.com>
> wrote:
>
>> Does it really even need the linear to exp convertor ?  The feedback loop
>> will force it to the correct frequency.  Portamento could just use a
>> different charging function on the capacitor.
>>
>> ------------------------------
>> *From:* Neil Johnson <neil.johnson71 at gmail.com>
>> *Sent:* 05 July 2026 10:26
>> *To:* Michael E Caloroso <mec.forumreader at gmail.com>
>> *Cc:* Mike Bryant <mbryant at futurehorizons.com>; SYNTH DIY <
>> synth-diy at synth-diy.org>
>> *Subject:* Re: [sdiy] GRP Genesi
>>
>> Michael E Caloroso wrote:
>>
>> US 3,930,429
>>
>>
>> Don did a write-up of it here:
>> https://till.com/articles/arp/patents.html#US03930429
>> Very weird architecture indeed!
>>
>> Neil
>>
> ________________________________________________________
> 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
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260706/8d986e13/attachment.htm>

From modular at go2.pl  Mon Jul  6 13:06:14 2026
From: modular at go2.pl (Roman Sowa)
Date: Mon, 6 Jul 2026 13:06:14 +0200
Subject: [sdiy] GRP Genesi
In-Reply-To: <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
 <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
 <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAAv6=UBHa3YgE_EsWg00fdXkAB8Vc=D4BbV7636p+gXVPPoJ9Q@mail.gmail.com>
 <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>
Message-ID: <64ac45c1-87e6-4c80-a7e7-738db1ac50c8@go2.pl>

At first glimpse, just looking at block diagram, it looks like typical 
PLL, but instead of phase comparator it uses F-to-V conversion and 
voltage comparator. Same divider ratio is used in the feedback as in the 
vaweform output, so the VCO works only within 1 octave while overall 
output spans over many octaves.

Roman

W dniu 2026-07-05 o?11:26, Neil Johnson via Synth-diy pisze:
> Michael E Caloroso wrote:
> 
>     US 3,930,429
> 
> 
> Don did a write-up of it here: 
> https://till.com/articles/arp/patents.html#US03930429 
> <https://till.com/articles/arp/patents.html#US03930429>
> Very?weird architecture indeed!
> 
> Neil
> 
> ________________________________________________________
> 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 mbryant at futurehorizons.com  Mon Jul  6 14:01:38 2026
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Mon, 6 Jul 2026 12:01:38 +0000
Subject: [sdiy] GRP Genesi
In-Reply-To: <64ac45c1-87e6-4c80-a7e7-738db1ac50c8@go2.pl>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
 <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
 <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAAv6=UBHa3YgE_EsWg00fdXkAB8Vc=D4BbV7636p+gXVPPoJ9Q@mail.gmail.com>
 <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>
 <64ac45c1-87e6-4c80-a7e7-738db1ac50c8@go2.pl>
Message-ID: <CWLP265MB7132035B0620077521D337ACDBF12@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

Actually one of the cleverest bits is probably converting the down-scaled squarewaves to sawtooths whilst keeping the levels consistent across the whole frequency range.  No mention of how they did they - presumably by programming a constant current source with the key and octave number ?
________________________________
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: 06 July 2026 12:06
To: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: Re: [sdiy] GRP Genesi

At first glimpse, just looking at block diagram, it looks like typical
PLL, but instead of phase comparator it uses F-to-V conversion and
voltage comparator. Same divider ratio is used in the feedback as in the
vaweform output, so the VCO works only within 1 octave while overall
output spans over many octaves.

Roman

W dniu 2026-07-05 o 11:26, Neil Johnson via Synth-diy pisze:
> Michael E Caloroso wrote:
>
>     US 3,930,429
>
>
> Don did a write-up of it here:
> https://till.com/articles/arp/patents.html#US03930429
> <https://till.com/articles/arp/patents.html#US03930429>
> Very weird architecture indeed!
>
> Neil
>
> ________________________________________________________
> 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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260706/ff0c1977/attachment.htm>

From ben at stuyts.nl  Mon Jul  6 18:05:33 2026
From: ben at stuyts.nl (Ben Stuyts)
Date: Mon, 6 Jul 2026 18:05:33 +0200
Subject: [sdiy] [ADMIN] Read this if you suddenly received a ton of
 synth-diy messages
Message-ID: <03DC10E5-E80D-400E-8A2C-0F1A226C7666@stuyts.nl>

Hi,

There are a few accounts which have just received a metric ton of synth-diy messages.

If this was you, they were back-logged because our mail server refused to negotiate a secure connection with your mail server.

- Our mail server now refuses to connect to servers with outdated TLS negotiation. Only supports STARTTLS.
- Or your server only supports legacy sigalg (typically SHA-1 or another obsolete algorithm).

I have now added exceptions for these domains, so they do not use any TLS at all.

All hail the server OS upgrades.

Ben



From tmowbray at ihug.com.au  Mon Jul  6 22:02:48 2026
From: tmowbray at ihug.com.au (Tony Mowbray)
Date: Tue, 7 Jul 2026 06:02:48 +1000
Subject: [sdiy] [ADMIN] Read this if you suddenly received a ton of
 synth-diy messages
In-Reply-To: <03DC10E5-E80D-400E-8A2C-0F1A226C7666@stuyts.nl>
References: <03DC10E5-E80D-400E-8A2C-0F1A226C7666@stuyts.nl>
Message-ID: <023601dd0d82$6e14f640$4a3ee2c0$@ihug.com.au>

Indeed, all hail server upgrades...



Kind Regards

Tony Mowbray

-----Original Message-----
From: Synth-diy <synth-diy-bounces at synth-diy.org> On Behalf Of Ben Stuyts
via Synth-diy
Sent: Tuesday, 7 July 2026 2:06 AM
To: SDIY List <synth-diy at synth-diy.org>
Subject: [sdiy] [ADMIN] Read this if you suddenly received a ton of
synth-diy messages

Hi,

There are a few accounts which have just received a metric ton of synth-diy
messages.

If this was you, they were back-logged because our mail server refused to
negotiate a secure connection with your mail server.

- Our mail server now refuses to connect to servers with outdated TLS
negotiation. Only supports STARTTLS.
- Or your server only supports legacy sigalg (typically SHA-1 or another
obsolete algorithm).

I have now added exceptions for these domains, so they do not use any TLS at
all.

All hail the server OS upgrades.

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


From tom at electricdruid.net  Tue Jul  7 00:25:30 2026
From: tom at electricdruid.net (Tom Wiltshire)
Date: Mon, 6 Jul 2026 23:25:30 +0100
Subject: [sdiy] GRP Genesi
In-Reply-To: <CWLP265MB7132035B0620077521D337ACDBF12@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
 <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
 <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAAv6=UBHa3YgE_EsWg00fdXkAB8Vc=D4BbV7636p+gXVPPoJ9Q@mail.gmail.com>
 <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>
 <64ac45c1-87e6-4c80-a7e7-738db1ac50c8@go2.pl>
 <CWLP265MB7132035B0620077521D337ACDBF12@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <3AFB0585-C412-4851-9DF7-9BB40299791E@electricdruid.net>

Isn't it just the typical adding-up-a-load-of-octave-squarewaves to make a staircase "ramp" waveform? 6 bits in this case, iirc.

Ah, yes, here it is, from the service manual:



> On 6 Jul 2026, at 13:01, Mike Bryant <mbryant at futurehorizons.com> wrote:
> 
> Actually one of the cleverest bits is probably converting the down-scaled squarewaves to sawtooths whilst keeping the levels consistent across the whole frequency range.  No mention of how they did they - presumably by programming a constant current source with the key and octave number ?
> 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: 06 July 2026 12:06
> To: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
> Subject: Re: [sdiy] GRP Genesi
>  
> At first glimpse, just looking at block diagram, it looks like typical 
> PLL, but instead of phase comparator it uses F-to-V conversion and 
> voltage comparator. Same divider ratio is used in the feedback as in the 
> vaweform output, so the VCO works only within 1 octave while overall 
> output spans over many octaves.
> 
> Roman
> 
> W dniu 2026-07-05 o 11:26, Neil Johnson via Synth-diy pisze:
> > Michael E Caloroso wrote:
> > 
> >     US 3,930,429
> > 
> > 
> > Don did a write-up of it here: 
> > https://till.com/articles/arp/patents.html#US03930429 <https://till.com/articles/arp/patents.html#US03930429> 
> > <https://till.com/articles/arp/patents.html#US03930429 <https://till.com/articles/arp/patents.html#US03930429>>
> > Very weird architecture indeed!
> > 
> > Neil
> > 
> > ________________________________________________________
> > 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
> ________________________________________________________
> 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
> ________________________________________________________
> 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>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260706/9d7e89ec/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: PastedGraphic-8.png
Type: image/png
Size: 199447 bytes
Desc: not available
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260706/9d7e89ec/attachment.png>

From tom at electricdruid.net  Tue Jul  7 01:16:22 2026
From: tom at electricdruid.net (Tom Wiltshire)
Date: Tue, 7 Jul 2026 00:16:22 +0100
Subject: [sdiy] GRP Genesi
In-Reply-To: <CWLP265MB7132D4C8CAC706998A2AB773DBF12@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
 <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
 <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAAv6=UBHa3YgE_EsWg00fdXkAB8Vc=D4BbV7636p+gXVPPoJ9Q@mail.gmail.com>
 <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>
 <64ac45c1-87e6-4c80-a7e7-738db1ac50c8@go2.pl>
 <CWLP265MB7132035B0620077521D337ACDBF12@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <3AFB0585-C412-4851-9DF7-9BB40299791E@electricdruid.net>
 <CWLP265MB7132D4C8CAC706998A2AB773DBF12@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <A2EB3A92-92F3-44FD-A0D3-31F8F5F1DA72@electricdruid.net>

Missing the 64th, 128th, 192nd, 256th harmonic (etc) but otherwise identical. The 64th harmonic is -36dB down so it's probably audible but hardly a big deal. In my view, it's close enough for synthesis - this is raw material, not a pure test signal. Is it rich and does it provide plenty to work with? Yep!
The Roland Alpha Juno "DCO" chip (NCO really) does the same thing, but manages to produce an 8-bit staircase, which reduces the errors even further. No-one ever complained the "Hoover" synth wasn't producing a rich enough waveform!


> On 6 Jul 2026, at 23:27, Mike Bryant <mbryant at futurehorizons.com> wrote:
> 
> Ah right.  Not really a proper sawtooth then.  Thanks
> 
> From: Tom Wiltshire <tom at electricdruid.net>
> Sent: 06 July 2026 23:25
> To: Mike Bryant <mbryant at futurehorizons.com>
> Cc: synth-diy at synth-diy.org <synth-diy at synth-diy.org>; Roman Sowa <modular at go2.pl>
> Subject: Re: [sdiy] GRP Genesi
>  
> Isn't it just the typical adding-up-a-load-of-octave-squarewaves to make a staircase "ramp" waveform? 6 bits in this case, iirc.
> 
> Ah, yes, here it is, from the service manual:
> 
> <PastedGraphic-8.png>
> 
>> On 6 Jul 2026, at 13:01, Mike Bryant <mbryant at futurehorizons.com <mailto:mbryant at futurehorizons.com>> wrote:
>> 
>> Actually one of the cleverest bits is probably converting the down-scaled squarewaves to sawtooths whilst keeping the levels consistent across the whole frequency range.  No mention of how they did they - presumably by programming a constant current source with the key and octave number ?
>>   
>> From: Synth-diy <synth-diy-bounces at synth-diy.org <mailto:synth-diy-bounces at synth-diy.org>> on behalf of Roman Sowa via Synth-diy <synth-diy at synth-diy.org <mailto:synth-diy at synth-diy.org>>
>> Sent: 06 July 2026 12:06
>> 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] GRP Genesi
>>  
>> At first glimpse, just looking at block diagram, it looks like typical 
>> PLL, but instead of phase comparator it uses F-to-V conversion and 
>> voltage comparator. Same divider ratio is used in the feedback as in the 
>> vaweform output, so the VCO works only within 1 octave while overall 
>> output spans over many octaves.
>> 
>> Roman
>> 
>> W dniu 2026-07-05 o 11:26, Neil Johnson via Synth-diy pisze:
>> > Michael E Caloroso wrote:
>> > 
>> >     US 3,930,429
>> > 
>> > 
>> > Don did a write-up of it here: 
>> > https://till.com/articles/arp/patents.html#US03930429 <https://till.com/articles/arp/patents.html#US03930429> 
>> > <https://till.com/articles/arp/patents.html#US03930429 <https://till.com/articles/arp/patents.html#US03930429>>
>> > Very weird architecture indeed!
>> > 
>> > Neil
>> > 
>> > ________________________________________________________
>> > 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
>> 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>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260707/b90238c2/attachment.htm>

From mec.forumreader at gmail.com  Tue Jul  7 02:25:51 2026
From: mec.forumreader at gmail.com (Michael E Caloroso)
Date: Mon, 6 Jul 2026 20:25:51 -0400
Subject: [sdiy] GRP Genesi
In-Reply-To: <3AFB0585-C412-4851-9DF7-9BB40299791E@electricdruid.net>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
 <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
 <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAAv6=UBHa3YgE_EsWg00fdXkAB8Vc=D4BbV7636p+gXVPPoJ9Q@mail.gmail.com>
 <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>
 <64ac45c1-87e6-4c80-a7e7-738db1ac50c8@go2.pl>
 <CWLP265MB7132035B0620077521D337ACDBF12@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <3AFB0585-C412-4851-9DF7-9BB40299791E@electricdruid.net>
Message-ID: <CAAv6=UBPLv9gkqdEE28DjpU34w-J0-UN5DCm7iw5DmYYCCjxvg@mail.gmail.com>

"...the first read only memories ...64 bits"

The ProSoloist used the 7488 OTP PROM - made by TI - for instant patch
changes.  The 7488 had a capacity of 256 bits (not KB or MB!) in an 8x32
matrix - each PROM had 8 control lines for the 30 ProSoloist/ProDGX presets
(two addresses were unused "off"), and there were eight of these PROMs in
the PS.  Access time was a snappy 26ns (compared to 2-300 millisecond
access of later 27xxx EPROMs).  Jeremy exploited the open collector output
feature of those PROMs to enable or disable ProSoloist circuits by shorting
control lines to ground through the PROM output when the OC output was a
logic '1'.

I don't think any programmer had a profile for those old PROMs.  They
last appeared in a 1977 databook, yet ARP kept using them to make Pro/DGXs
into 1981...!

That novel feature was covered in the patent.  Other competitors - Moog,
Roland, Yamaha, etc - had their preset synths but none lasted as long as
the PS, and I don't think any of them could use PROMs for preset control
without infringing the patent.  I know that the Moog Satellite used a
matrix of fixed resistors for preset configuration, which ARP had abandoned
with the unreliable Soloist.

Woe for the 1970s repair tech who had to fix a malfunctioning ProSoloist
VCO... few if any understood what made it tick.  I asked a tech from those
days if he had fixed ARPs - "Woah... Evil..." (sign of the cross) :D

MC

On Mon, Jul 6, 2026 at 6:35?PM Tom Wiltshire <tom at electricdruid.net> wrote:

> Isn't it just the typical adding-up-a-load-of-octave-squarewaves to make a
> staircase "ramp" waveform? 6 bits in this case, iirc.
>
> Ah, yes, here it is, from the service manual:
>
>
>
> On 6 Jul 2026, at 13:01, Mike Bryant <mbryant at futurehorizons.com> wrote:
>
> Actually one of the cleverest bits is probably converting the down-scaled
> squarewaves to sawtooths whilst keeping the levels consistent across the
> whole frequency range.  No mention of how they did they - presumably by
> programming a constant current source with the key and octave number ?
> ------------------------------
> *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:* 06 July 2026 12:06
> *To:* synth-diy at synth-diy.org <synth-diy at synth-diy.org>
> *Subject:* Re: [sdiy] GRP Genesi
>
> At first glimpse, just looking at block diagram, it looks like typical
> PLL, but instead of phase comparator it uses F-to-V conversion and
> voltage comparator. Same divider ratio is used in the feedback as in the
> vaweform output, so the VCO works only within 1 octave while overall
> output spans over many octaves.
>
> Roman
>
> W dniu 2026-07-05 o 11:26, Neil Johnson via Synth-diy pisze:
> > Michael E Caloroso wrote:
> >
> >     US 3,930,429
> >
> >
> > Don did a write-up of it here:
> > https://till.com/articles/arp/patents.html#US03930429
> > <https://till.com/articles/arp/patents.html#US03930429>
> > Very weird architecture indeed!
> >
> > Neil
> >
> > ________________________________________________________
> > 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
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260706/6759b95f/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: PastedGraphic-8.png
Type: image/png
Size: 199447 bytes
Desc: not available
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260706/6759b95f/attachment.png>

From synthdiy at adambaby.com  Tue Jul  7 04:53:02 2026
From: synthdiy at adambaby.com (Adam (synthDIY))
Date: Tue, 7 Jul 2026 12:53:02 +1000
Subject: [sdiy] GRP Genesi
In-Reply-To: <A2EB3A92-92F3-44FD-A0D3-31F8F5F1DA72@electricdruid.net>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
 <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
 <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAAv6=UBHa3YgE_EsWg00fdXkAB8Vc=D4BbV7636p+gXVPPoJ9Q@mail.gmail.com>
 <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>
 <64ac45c1-87e6-4c80-a7e7-738db1ac50c8@go2.pl>
 <CWLP265MB7132035B0620077521D337ACDBF12@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <3AFB0585-C412-4851-9DF7-9BB40299791E@electricdruid.net>
 <CWLP265MB7132D4C8CAC706998A2AB773DBF12@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <A2EB3A92-92F3-44FD-A0D3-31F8F5F1DA72@electricdruid.net>
Message-ID: <C9EB0BAA-8BA3-4761-AAA2-DC005A0DC1D1@adambaby.com>



> On 7 Jul 2026, at 09:16, Tom Wiltshire <tom at electricdruid.net> wrote:
> 
> No-one ever complained the "Hoover" synth wasn't producing a rich enough waveform!


LOL!!

The Roland SH-2000 is another preset synth with stair-step waveforms. Rich waveforms for that great filter to chew on.

A
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20260707/98c29df1/attachment.htm>

From don at till.com  Tue Jul  7 05:24:36 2026
From: don at till.com (Donald Tillman)
Date: Mon, 6 Jul 2026 20:24:36 -0700
Subject: [sdiy] GRP Genesi
In-Reply-To: <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
 <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
 <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAAv6=UBHa3YgE_EsWg00fdXkAB8Vc=D4BbV7636p+gXVPPoJ9Q@mail.gmail.com>
 <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>
Message-ID: <DC7A91DF-5F23-4E0C-BADB-8A3AA9B37E29@till.com>

On Jul 5, 2026, at 2:26?AM, Neil Johnson via Synth-diy <synth-diy at synth-diy.org> wrote:

> Michael E Caloroso wrote:
> US 3,930,429
> 
> Don did a write-up of it here: https://till.com/articles/arp/patents.html#US03930429
> Very weird architecture indeed!

Hiya,

My memory is telling me that there may be significant differences between the patent and the actual product.  (I'm not in the mood to check at the moment; there's a lot to go through there.)


  -- Don
--
Donald Tillman, Palo Alto, California
https://till.com

From don at till.com  Tue Jul  7 05:33:55 2026
From: don at till.com (Donald Tillman)
Date: Mon, 6 Jul 2026 20:33:55 -0700
Subject: [sdiy] GRP Genesi
In-Reply-To: <3AFB0585-C412-4851-9DF7-9BB40299791E@electricdruid.net>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
 <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
 <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAAv6=UBHa3YgE_EsWg00fdXkAB8Vc=D4BbV7636p+gXVPPoJ9Q@mail.gmail.com>
 <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>
 <64ac45c1-87e6-4c80-a7e7-738db1ac50c8@go2.pl>
 <CWLP265MB7132035B0620077521D337ACDBF12@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <3AFB0585-C412-4851-9DF7-9BB40299791E@electricdruid.net>
Message-ID: <C7B42582-9AED-493B-9014-6D803C96E166@till.com>

Yeah, building a sawtooth wave by summing the square waves from the higher divide-down octaves was standard practice for many electronic organs back in the day.  The Schober organs for sure.  

There are fewer octaves to sum on the higher notes, sure, but that's okay.

  -- Don
--
Donald Tillman, Palo Alto, California
https://till.com

> On Jul 6, 2026, at 3:25?PM, Tom Wiltshire <tom at electricdruid.net> wrote:
> 
> Isn't it just the typical adding-up-a-load-of-octave-squarewaves to make a staircase "ramp" waveform? 6 bits in this case, iirc.
> 
> Ah, yes, here it is, from the service manual:
> 
> 
>> On 6 Jul 2026, at 13:01, Mike Bryant <mbryant at futurehorizons.com> wrote:
>> 
>> Actually one of the cleverest bits is probably converting the down-scaled squarewaves to sawtooths whilst keeping the levels consistent across the whole frequency range.


From don at till.com  Tue Jul  7 05:36:58 2026
From: don at till.com (Donald Tillman)
Date: Mon, 6 Jul 2026 20:36:58 -0700
Subject: [sdiy] GRP Genesi
In-Reply-To: <CAAv6=UBPLv9gkqdEE28DjpU34w-J0-UN5DCm7iw5DmYYCCjxvg@mail.gmail.com>
References: <CAGHPcSBbwJvrOOqSTfwXODVFKDG19sZZx5Xj7a9Bwy9R1N_jFg@mail.gmail.com>
 <C19E2071-6FB4-421C-AC93-6655AEDAC5F3@adambaby.com>
 <CAGHPcSAZOX7HGnQ9W2tKsxYo83dq-WAuQT2nugP=B0bK_jLBHA@mail.gmail.com>
 <CAAv6=UCy=i+7gjK9g0r1wYb0Aq0kLgQfwBBqRkGfx530=A-z9Q@mail.gmail.com>
 <CAAv6=UBx7gjTYbJ0zNfqDV2OuUWQhizaQGknfkBzP8tdQhfLyg@mail.gmail.com>
 <CWLP265MB71328C23271EEC82E8C9A8E4DBF32@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAAv6=UBHa3YgE_EsWg00fdXkAB8Vc=D4BbV7636p+gXVPPoJ9Q@mail.gmail.com>
 <CACZGMxLj=HkVA=285xtNOQhOPqgauNNjq8HrRDyvWJMcY2dEGg@mail.gmail.com>
 <64ac45c1-87e6-4c80-a7e7-738db1ac50c8@go2.pl>
 <CWLP265MB7132035B0620077521D337ACDBF12@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <3AFB0585-C412-4851-9DF7-9BB40299791E@electricdruid.net>
 <CAAv6=UBPLv9gkqdEE28DjpU34w-J0-UN5DCm7iw5DmYYCCjxvg@mail.gmail.com>
Message-ID: <C93682CE-2DDA-4FDF-A2A6-94528FD5A0A5@till.com>

On Jul 6, 2026, at 5:25?PM, Michael E Caloroso via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> 
> 
> Other competitors - Moog, Roland, Yamaha, etc - had their preset synths but none lasted as long as the PS [...]

Nobody else had the Tony Banks solo from Genesis' "Cinema Show".

  -- Don
--
Donald Tillman, Palo Alto, California
https://till.com



From cheater00social at gmail.com  Tue Jul  7 06:39:58 2026
From: cheater00social at gmail.com (cheater cheater)
Date: Tue, 7 Jul 2026 06:39:58 +0200
Subject: [sdiy] Converting rack mount to DC input?
In-Reply-To: <CAP92RBWx-2FkgpQROx+Jd-Zag5FtUnhL5zYu9Q3X6S5sDynq1g@mail.gmail.com>
References: <CAGn5V-_OFFANadzX+JEFwrsr3XabJJ9pC_Y7BN89A3zFES0v0w@mail.gmail.com>
 <63165836-a201-4cc3-9a3c-5a2f2b2226f5@mnet-online.de>
 <CAP92RBWx-2FkgpQROx+Jd-Zag5FtUnhL5zYu9Q3X6S5sDynq1g@mail.gmail.com>
Message-ID: <CAGn5V-8PfSpdHULbMMRjnXXOxprnVqkcRWo+Uh=ijHDhsbynLQ@mail.gmail.com>

Don't you think this may have had something to do with you
distributing AC power, rather than DC with 0V potential?

On Sat, Jul 4, 2026 at 11:33?PM Mattias Rickardsson <mr at analogue.org> wrote:
>
> Den l?r 4 juli 2026 14:23Florian Anwander via Synth-diy <synth-diy at synth-diy.org> skrev:
>>
>> Maybe, it's a stupid thought, but...: could it be that a device relies on beeing galvanical separated from other devices. I this case the common supply might clash with the devices concept.
>
>
> This reminds me of a somewhat similar issue I had many years ago:
>
> I wanted a Korg MS-20 and a Korg KR-55 to share one external power puck. (Swedish-sold old Korgs had a big external power transformer to step down from 220 V AC to 16 V AC, which is then what the instrument then accepts via a plug with 2 flat prongs that doesn't seem roadworthy with European electrical standards.)
>
> So I made a short splitter Y cable on the 16 V AC side and attached both instruments and turned them on. But then I connected an audio cable between them (or audio cables from both units to the same mixer) and I had a blown fuse! It was apparently not okay to connect those two grounds together when running off the same AC supply.
>
> /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 oleavitt at proton.me  Tue Jul  7 07:14:28 2026
From: oleavitt at proton.me (Oren Leavitt)
Date: Tue, 07 Jul 2026 05:14:28 +0000
Subject: [sdiy] [ADMIN] Read this if you suddenly received a ton of
 synth-diy messages
In-Reply-To: <03DC10E5-E80D-400E-8A2C-0F1A226C7666@stuyts.nl>
References: <03DC10E5-E80D-400E-8A2C-0F1A226C7666@stuyts.nl>
Message-ID: <e402ea6b-6908-4922-a904-f31efb0f4620@proton.me>

Should be good for another 30 years!

Thanks for keeping Synth-diy going!

On 7/6/26 11:05 AM, Ben Stuyts via Synth-diy wrote:
> Hi,
> 
> There are a few accounts which have just received a metric ton of synth-diy messages.
> 
> If this was you, they were back-logged because our mail server refused to negotiate a secure connection with your mail server.
> 
> - Our mail server now refuses to connect to servers with outdated TLS negotiation. Only supports STARTTLS.
> - Or your server only supports legacy sigalg (typically SHA-1 or another obsolete algorithm).
> 
> I have now added exceptions for these domains, so they do not use any TLS at all.
> 
> All hail the server OS upgrades.
> 
> 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