[sdiy] VCA venting

[jays at aracnet.com]

Pat,

If you are using OTAs be careful. When I first started working with this OTAs 20 years ago I went through a number of them. They are not very tolerent to to much current on the Iabc or Id (if your OTA has one) pins. It's easy to give them to much current and fry them. Any more when I proto with OTAs I use a current limiting resistor on Iabc until I get the circuit under control.

Jay S.

Pat Kammerer <spivkurl at wearerecords.com> wrote :

> Hi,
> 
> I just had to vent...  When I got into Synth DIY I had this strange
> assumption that building VCAs would be easier than the other main modules.
> My recent experience has made this seem not the case.
> 
> I've built two different VCAs on perfboard, and both of them seem to have
> the same problem.  The CV does nothing.  I can get a signal, but no matter
> how I trim it I can get the CV to work.  I can however get the CV to effect
> gain by sending it into a different point in the circuits.  This doesn't
> make any sense to me...
> 
> If anyone has any good general advise, then I would appreciate it, otherwise
> just ignore me.   : )
> 
> Thanks,
> Pat