[sdiy] linear to exponential CV converter

[Andre Majorel]

On 2007-11-20 01:45 +0100, Derek Holzer wrote:
> Dave Manley wrote:
>> Derek Holzer wrote:
>>
>>> Having conquered my voltage offset+gain task this evening with
>>> help from you fine folks, I'm now looking around for a simple
>>> linear-to-exponential CV converter circuit. Suggestions?
>>>
>> how accurate do you need it to be?
>> what will it control?
>
> Not super accurate, basic control of VCAs and VCF without need
> for exact frequency tracking. And adjustable...

I'd like to see such a circuit. The MS-20 has linear CV for the
VCO and exponential CV for the VCF, making proper keyboard
tracking impossible.

Let's see... The Korg MS-02 interface contains a log function.

  http://www.korganalogue.net/korgms/service/ms02/MS02schematic.jpg
  http://www.korganalogue.net/korgms/manuals/pp/0201.html (user manual)

It doesn't appear to be temperature-compensated. That may work OK
to control a VCF but not to control a VCO.

-- 
André Majorel <URL:http://www.teaser.fr/~amajorel/>
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