Eliminating VCA Noise?

A.S.P. ms20 at zebu.serv.net
Sun Mar 17 22:59:30 CET 1996

Hello You All,

I just tested my first VCA circuit.  It's the 3080 based one from 

It seems to work fine, except that theres this weird raspy RF type of 
crap mixed in with the signal.  I'm guessing that some caps will 
eliminate that problem, but I'm not sure what value and the best place to 
put them.  I've already put 100uF electrolytics from the rails to ground, 
right at the supply inputs.  This helped get rid of some of the noise.  I 
also tried putting .001uF and 91pF there but with no change.

Any tips?  Also, what are good cap values for eliminating DC thump from 
the cv inputs?



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