[sdiy] Small and simple vca details desired (oh, and a voltage invertor too)

[Harry Bissell Jr]

Hi Ray...

you might want to try adding a 15K resistor to the +15
and the linearizing diode terminal, and add a divider
and DC offset pot to the unused input terminal. Make
the input divider like a 30K : 1K.  This will make the
input signal red hot, and the linearizing diodes will
allow the signal through without distortion.

Downside... lower input impedance, and the need to use
the DC offset adjust. You 'might' like the soft
clipping of the circuit you have now...

Upside, lower noise and distortion

H^) harry


--- raywilson at comcast.net wrote:

> Check out
> 
>
http://www.musicfromouterspace.com/analogsynth/vca.html
> 
> Its small and simple.
> 
> Ray
> -------------- Original message -------------- 
> 
> > Not stripboard, but easy and reasonably low parts
> count....You could try 
> > the "irwin dual VCA" I have details and PCB's for
> it on my site. 
> > 
> > http://www.charlielamm.com/synth/duallinearvca.php
> 
> > 
> > 
> > On Wed, 2 Mar 2005, Julian wrote: 
> > 
> > > Hello, 
> > > 
> > > I want to build a vca bank. No pots, just each
> vca having 4 jacks - in and 
> > out, and 2 CV controls. Rather like doepfers a-132
> 
> > > dualvca, but i plan to have more then dual. 
> > > 
> > > Im pretty rubbish at building on stipboard, so
> the component count has to be 
> > low. 
> > > 
> > > Yeah, i know google will turf up 50k, but i was
> wanting a recommendation? 
> > > 
> > > Cheers, Julian 
> > > 
> > > ps. im trying to replace the utility modules in
> my commercial modular with 
> > diy stuff. ken stone does mixer pcbs real cheap,
> so ill 
> > > get some of them, but voltage invertors... (?) 
> > > 
> > > 
> > > 
> >