Eml synthesizers

::: converting 1.2 volt/octave to 1 volt/octave ::: 

Hello, i was noticing some discussion about changing the EML 101 to 1v/octave...

is it possible to do this on the EML200 as well?

is it really just a resistor change?  maybe a substitute for the 22k Swing resistor value?

or does the Center value need to change as well?
 
that would be a sweet mod!

Thanks!

Nick Z

The 200 and 101 oscillators are a non-standard 1.20v/oct 

hz/volt is more of a japan convention: korg, Yamaha, etc...

i can get mine to tune to other 1v/oct gear but its prone to drift as the 
controls are so course.

i was hoping to get a mod enacted with a fine tune VR so one of the swing inputs 
was always 1v/oct and could be calibrated as things settle and drift...

PS:

from WIKI:

http://en.wikipedia.org/wiki/CV/Gate#CV

CV 
While the concept of CV (Control Voltage) was fairly standard  on analog synths, 
the implementation was not. For pitch control via CV,  there are two prominent 
implementations:
	* Volts per octave. This standard was popularized by (if not created by) Bob 
Moog in the 1960s;  it was widely adopted for control interfacing.One volt 
represents one  octave, so the pitch produced by a voltage of 3 V would be one 
octave  lower than that produced by a voltage of 4 V. Notable followers of this  
standard include Roland, Moog, Sequential Circuits, Oberheim and ARP.
	* Hertz per volt. This method (used by most but not all Korg and Yamaha synths) 
represented an octave of pitch by doubling voltage, so the  pitch represented by 
2 V would be one octave lower than that represented  by 4 V, and one higher than 
that represented by 1 V.
The following example table demonstrates some notes and their  corresponding 
voltage levels in both implementations (this example uses 1  V/octave and 
55 Hz/V):
z


 NEW ALLIANCE EAST!!!!


--------------------------------------

http://www.newallianceeast.com

http://www.newallianceaudio.com

http://www.myspace.com/newallianceaudio

http://www.c4rt.com

www.myspace.com/thecampaignforrealtime




________________________________

From: Prosper Prodaniuk <prosperp@...>
To: emlsynth@yahoogroups.com
Sent: Tue, July 19, 2011 2:54:33 PM
Subject: [emlsynth] Re: converting 1.2 volt/octave to 1 volt/octave

  
Maybe in this someone can answer whether or not the 200 (and 100) are HZ/V as 
opposed to V/OCT and then they went with the V/OCT convention for the 101 and 
beyond. Have heard this on more than a few occasions. Also does anyone have the 
user and/or service manual for the 100? I'm looking to integrate it more into my 
system but don't want to blow anything up.

I know the difference i just had heard hz/v mentioned for them. A guy playing his with a MS-20 etc.

On 2011-07-19 12:15 PM, "Nick Zampiello" <newallianceeast@...> wrote:

The 200 and 101 oscillators are a non-standard 1.20v/oct

hz/volt is more of a japan convention: korg, Yamaha, etc...

i can get mine to tune to other 1v/oct gear but its prone to drift as the controls are so course.

i was hoping to get a mod enacted with a fine tune VR so one of the swing inputs was always 1v/oct and could be calibrated as things settle and drift...

PS:

from WIKI:

http://en.wikipedia.org/wiki/CV/Gate#CV

CV

While the concept of CV (Control Voltage) was fairly standard on analog synths, the implementation was not. For pitch control via CV, there are two prominent implementations:

• Volts per octave. This standard was popularized by (if not created by) Bob Moog in the 1960s; it was widely adopted for control interfacing.One volt represents one octave, so the pitch produced by a voltage of 3 V would be one octave lower than that produced by a voltage of 4 V. Notable followers of this standard include Roland, Moog, Sequential Circuits, Oberheim and ARP.

• Hertz per volt. This method (used by most but not all Korg and Yamaha synths) represented an octave of pitch by doubling voltage, so the pitch represented by 2 V would be one octave lower than that represented by 4 V, and one higher than that represented by 1 V.

The following example table demonstrates some notes and their corresponding voltage levels in both implementations (this example uses 1 V/octave and 55 Hz/V):

z

NEW ALLIANCE EAST!!!!


--------------------------------------

http://www.newallianceeast.com

http://www.newallianceaudio.com

http://www.myspace.com/newallianceaudio

http://www.c4rt.com

www.myspace.com/thecampaignforrealtime

i never had any luck trying to get the EML to track to any hz/volt synth...

it just can't scale that far beyond 1.2 v/oct...

the way the controls are on mine it's almost impossible to keep it in tune 
scaled to 1v/oct with both osc in tune...

maybe he was using the pitch tracker on the MS20 to make it chase the EML osc...
the 'swing' on the ms20 pitch tracker can co from 0-2x or so i believe....
maybe he tricked it into being in tune in a smaller range...

hmmmmm.....


z

 NEW ALLIANCE EAST!!!!


--------------------------------------

http://www.newallianceeast.com

http://www.newallianceaudio.com

http://www.myspace.com/newallianceaudio

http://www.c4rt.com

www.myspace.com/thecampaignforrealtime




________________________________
From: Prosper Prodaniuk <prosperp@...>
To: emlsynth@yahoogroups.com
Sent: Tue, July 19, 2011 3:17:51 PM
Subject: Re: [emlsynth] Re: converting 1.2 volt/octave to 1 volt/octave

  
I know the difference i just had heard hz/v mentioned for them. A guy playing 
his with a MS-20 etc.
On 2011-07-19 12:15 PM, "Nick Zampiello" <newallianceeast@...> wrote:
>
> 
>  
>The 200 and 101 oscillators are a non-standard 1.20v/oct 
>
>hz/volt is more of a japan convention: korg, Yamaha, etc...
>
>i can get mine to tune to other 1v/oct gear but its prone to drift as the 
>controls are so course.
>
>i was hoping to get a mod enacted with a fine tune VR so one of the swing inputs 
>was always 1v/oct and could be calibrated as things settle and drift...
>
>PS:
>
>from WIKI:
>
>http://en.wikipedia.org/wiki/CV/Gate#CV
>
>CV 
>While the concept of CV (Control Voltage) was fairly standard  on analog synths, 
>the implementation was not. For pitch control via CV,  there are two prominent 
>implementations:
>	* Volts per octave. This standard was popularized by (if not created by) Bob 
>Moog in the 1960s;  it was widely adopted for control interfacing.One volt 
>represents one  octave, so the pitch produced by a voltage of 3 V would be one 
>octave  lower than that produced by a voltage of 4 V. Notable followers of this  
>standard include Roland, Moog, Sequential Circuits, Oberheim and ARP.
>	* Hertz per volt. This method (used by most but not all Korg and Yamaha synths) 
>represented an octave of pitch by doubling voltage, so the  pitch represented by 
>2 V would be one octave lower than that represented  by 4 V, and one higher than 
>that represented by 1 V.
>The following example table demonstrates some notes and their  corresponding 
>voltage levels in both implementations (this example uses 1  V/octave and 
>55 Hz/V):
>z
>
>
> NEW ALLIANCE EAST!!!!
>
>
>--------------------------------------
>
>http://www.newallianceeast.com
>
>http://www.newallianceaudio.com
>
>http://www.myspace.com/newallianceaudio
>
>http://www.c4rt.com
>
>www.myspace.com/thecampaignforrealtime
>
>
>
>
>
________________________________

 From: Prosper Prodaniuk <prosperp@gmail.com>
>To: emlsynth@yahoogroups.com
>Sent: Tue, July 19, 2011 2:54:33 PM
>Subject: [emlsynth] Re: converting 1.2 volt/octave to 1 volt/octave
>
>
> 
>
>Maybe in this someone can answer whether or not the 200 (and 100) are HZ/V as 
>opposed to V/OCT a...

> The 200 and 101 oscillators are a non-standard 1.20v/oct 


Are you sure about the 200?  The schematic I've seen looks
like a V/Hz oscillator.  Or was there a later version of the 200
(201?)

Steve

umm, now i'm confused!

sorry...


z



 NEW ALLIANCE EAST!!!!


--------------------------------------

http://www.newallianceeast.com

http://www.newallianceaudio.com

http://www.myspace.com/newallianceaudio

http://www.c4rt.com

www.myspace.com/thecampaignforrealtime




________________________________

From: "sprgroups@..." <sprgroups@...>
To: emlsynth@yahoogroups.com
Sent: Wed, July 20, 2011 6:45:05 PM
Subject: Re: [emlsynth] Re: converting 1.2 volt/octave to 1 volt/octave

  

> The 200 and 101 oscillators are a non-standard 1.20v/oct 

Are you sure about the 200?  The schematic I've seen looks
like a V/Hz oscillator.  Or was there a later version of the 200
(201?)

Steve

The 200 is basically just a bare integrator IC with a UJT, cap and diode
network in the feedback loop. The center frequency and both swings are all
summed together after their input resistors into the ame op amp input as the
feedback network. The diode and UJT act as choppers to produce the sawtooth
output from the integrator.
 
The output of the op amp goes to the 470 ohm output impedance resistor and
capacitively coupled to the two outputs, which are hardwired to each other.
 
There's no current control, differentiation or exponential amplifier. So, it
doesn't look like it was designed with any sort of scaling capacity in mind.



  _____  

From: emlsynth@yahoogroups.com [mailto:emlsynth@yahoogroups.com] On Behalf
Of sprgroups@...
Sent: Wednesday, July 20, 2011 3:45 PM
To: emlsynth@yahoogroups.com
Subject: Re: [emlsynth] Re: converting 1.2 volt/octave to 1 volt/octave


  


> The 200 and 101 oscillators are a non-standard 1.20v/oct 

Are you sure about the 200? The schematic I've seen looks
like a V/Hz oscillator. Or was there a later version of the 200
(201?)

Steve

So, i knew something was confusing and i looked into my old emails...

dave wilson of NESM had explained it to me before and i just remembered it 
backwards:


"The Museum is doing well. The VCOs on the 200 are Hz/Volt, not Oct/Volt, so  
they can be made to
track your Korg MS-20 or your Yamaha CS-40M, but not an ARP or Moog  
synthesizer. The EML 101
has an output called "CM2" (Control Mode 2) that is a Hz/Volt output that  can 
drive the 200's VCOs.
Older EML 101s have a CM3, same thing but high note priority for duophonic;  
More recent 101s have
a Sequencer input jack instead."

z


 NEW ALLIANCE EAST!!!!


--------------------------------------

http://www.newallianceeast.com

http://www.newallianceaudio.com

http://www.myspace.com/newallianceaudio

http://www.c4rt.com

www.myspace.com/thecampaignforrealtime




________________________________
From: George Mattson <axisair@comcast.net>
To: emlsynth@yahoogroups.com
Sent: Wed, July 20, 2011 8:40:28 PM
Subject: RE: [emlsynth] Re: converting 1.2 volt/octave to 1 volt/octave

  
The 200 is basically just a bare integrator IC with a UJT,  cap and diode 
network in the feedback loop. The center frequency and both  swings are all 
summed together after their input resistors into the ame op amp  input as the 
feedback network. The diode and UJT act as choppers to produce the  sawtooth 
output from the integrator.
 
The output of the op amp goes to the 470 ohm output impedance  resistor and 
capacitively coupled to the two outputs, which are hardwired to  each other.
 
There's no current control, differentiation or exponential  amplifier. So, it 
doesn't look like it was designed with any sort of scaling  capacity in mind. 


________________________________
 From: emlsynth@yahoogroups.com    [mailto:emlsynth@...m] On Behalf 
Of sprgroups@...

>Sent: Wednesday, July 20, 2011 3:45    PM
>To: emlsynth@yahoogroups.com
>Subject: Re: [emlsynth]    Re: converting 1.2 volt/octave to 1 volt/octave
>
>  
>
>> The 200 and 101 oscillators are a non-standard 1.20v/oct 
>
>Are you sure about the 200? The schematic I've seen looks
>like a    V/Hz oscillator. Or was there a later version of the    200
>(201?)
>
>Steve 
>

As far as I know there are two issues at play for HZ/V/Oct.

1 - The octave scaling everyone talks about. Technically you can calibrate one octave between the 101 and another V/Oct synth. You can luxury of getting say, a low C and a high C to be 'in tune'.

2 - Each note within that octave has to scale logarithmically, and this is actually the root of the problem. It's a separate conversion altogether. A V/Oct synth scales up in a linear fashion. A HZ/V/Oct synth scales up in a non-linear fashion, logarithmically, so the octave tuning has no bearing on what happens with all these notes in between. The 101 exponentially scales as you move up from one note to another so it will always be way out of tune until it reaches your calibrated 1.2V, then it's way off forevermore past your calibrated octave.

Hi Guys

I posted photos in 2007 of the schematics (http://groups.yahoo.com/group/emlsynth/photos/album/524942379/pic/list ) which I received from Dale Blake  to make a VP-1 Voltage Processor back in 1985, I've one in my 101 and 500 and worked fine with my ROLAND MPU 101 MIDI to CV CONVERTER, ARP sequencer and Octave Cat allowing the EMLs to track the 1V octaves with no problems.

Robert

--- In emlsynth@yahoogroups.com, Nick Zampiello <newallianceeast@...> wrote:

>
> i never had any luck trying to get the EML to track to any hz/volt synth...
> 
> it just can't scale that far beyond 1.2 v/oct...
> 
> the way the controls are on mine it's almost impossible to keep it in tune 
> scaled to 1v/oct with both osc in tune...
> 
> maybe he was using the pitch tracker on the MS20 to make it chase the EML osc...
> the 'swing' on the ms20 pitch tracker can co from 0-2x or so i believe....
> maybe he tricked it into being in tune in a smaller range...
> 
> hmmmmm.....
> 
> 
> z
> 
>  NEW ALLIANCE EAST!!!!
> 
> 
> --------------------------------------
> 
> http://www.newallianceeast.com
> 
> http://www.newallianceaudio.com
> 
> http://www.myspace.com/newallianceaudio
> 
> http://www.c4rt.com
> 
> www.myspace.com/thecampaignforrealtime
> 
> 
> 
> 
> ________________________________
> From: Prosper Prodaniuk <prosperp@...>
> To: emlsynth@yahoogroups.com
> Sent: Tue, July 19, 2011 3:17:51 PM
> Subject: Re: [emlsynth] Re: converting 1.2 volt/octave to 1 volt/octave
> 
>   
> I know the difference i just had heard hz/v mentioned for them. A guy playing 
> his with a MS-20 etc.
> On 2011-07-19 12:15 PM, "Nick Zampiello" <newallianceeast@...> wrote:
> >
> > 
> >  
> >The 200 and 101 oscillators are a non-standard 1.20v/oct 
> >
> >hz/volt is more of a japan convention: korg, Yamaha, etc...
> >
> >i can get mine to tune to other 1v/oct gear but its prone to drift as the 
> >controls are so course.
> >
> >i was hoping to get a mod enacted with a fine tune VR so one of the swing inputs 
> >was always 1v/oct and could be calibrated as things settle and drift...
> >
> >PS:
> >
> >from WIKI:
> >
> >http://en.wikipedia.org/wiki/CV/Gate#CV
> >
> >CV 
> >While the concept of CV (Control Voltage) was fairly standard  on analog synths, 
> >the implementation was not. For pitch control via CV,  there are two prominent 
> >implementations:
> >	* Volts per octave. This standard was popularized by (if not created by) Bob 
> >Moog in the 1960s;  it was widely adopted for control interfacing.One volt 
> >represents one  octave, so the pitch produced by a voltage of 3 V would be one 
> >octave  lower than that produced by a voltage of 4 V. Notable followers of this  
> >standard include Roland, Moog, Sequential Circuits, Oberheim and ARP.
> >	* Hertz per volt. This method (used by most but not all Korg and Yamaha synths) 
> >represented an octave of pitch by doubling voltage, so the  pitch represented by 
> >2 V would be one octave lower than that represented  by 4 V, and one higher than 
> >that represented by 1 V.
> >The following example table demonstrates some notes and their  corresponding 
> >voltage levels in both implementations (this example uses 1  V/octave and 
> >55 Hz/V):
> >z
> >
> >
> > NEW ALLIANCE EAST!!!!
> >
> >
> >--------------------------------------
> >
> >http://www.newallianceeast.com
> >
> >http://www.newallianceaudio.com
> >
> >http://www.myspace.com/newallianceaudio
> >
> >http://www.c4rt.com
> >
> >www.myspace.com/thecampaignforrealtime
> >
> >
> >
> >
> >
> ________________________________
>  From: Prosper Prodaniuk <prosperp@...>
> >To: emlsynth@yahoogroups.com
> >Sent: Tue, July 19, 2011 2:54:33 PM
> >Subject: [emlsynth] Re: converting 1.2 volt/octave to 1 volt/octave
> >
> >
> > 
> >
> >Maybe in this someone can answer whether or not the 200 (and 100) are HZ/V as 
> >opposed to V/OCT a...
>