[sdiy] Buchla Lowpass Gate Switch

[Scott Stites]

Hey Fernando,

Whenever I'm messing with Vactrols and choosing between between linear or
expo control, it boils down to this:

For linear control, I just adapt Grant's control circuit for the # 3
Standard Wogglebug, which you'll see here:

http://www.musicsynthesizer.com/WoggleBug/WoggleBug.html

For expo, I adapt Rene Schmitz's control circuit for the VCO4069.  Put 15V
on the anode of the first Vactrol and connect the cathode of the last
Vactrol to the collector of T2, and Bobsyeruncle.  Works *great*!!

http://www.uni-bonn.de/~uzs159/

Cheers,
Scott

----- Original Message -----
From: "Fernando de Izuzquiza" <fdi at ran.es>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Sunday, August 15, 2004 11:38 AM
Subject: Re: [sdiy] Buchla Lowpass Gate Switch


> Anyhow, I think it could be great to redesign the control section (and
> use it with the B or C audio section)
>
>
> I don't know how-to though...
>
> I imagine a circuit that puts out 0-20mA (I think max is 30mA for the
> 5C3) for 0-10V with a series LED so you have an indication if you like.
> Before that, it can be good to have an input circuit where you can +/-
> scale and offset the incoming CV.
>
> May be with a switchable expo mode. May be you can control "more or
> less expo" in an easy way.
>
>
> This way we can explore the cv response and have all control options
> available. Or decide a final configuration/s and build the module/s
> with the control response you like.
>
> Fernando
>