yes, I understand it can be difficult to trouble shoot like this. Thanks for the reply.

I thought about swapping the ICs to see if it follows one but wanted to ask first. I will try that.

Thanks again.

--- In Doepfer_a100@yahoogroups.com , <yahoo@...> wrote:
>
> > I did a search of the database and didn't see anything describing this.
> >
> > I just got a used a-132 dual voltage controlled amplifier. The
> > upper VCA is functioning properly. The lower VCA is not working
> > properly. It has a very low output and "thumps" or "pops" when
> > it opens/closes no matter what signal I use to open it. There's
> > a very large difference in the upper and lower channels.
> >
> > I was passing audio through it and opening it with an LFO. The
> > upper channel behaves as expected but the lower does not with the
> > same signals.
> >
> > I also have another A-132 and both channels function very similar
> > and are similar to the upper channel on the problematic module.
> >
> > Anyone have any ideas where to look for the problem
>
> From the distance it's difficult to find out what's wrong. If you are
> experienced with electronics you could swap the integrated circuits of the
> upper and lower section to find out if one of the integrated circuits is
> defective. Maybe the module has to be readjusted (nothing but minimizing the
> "plop" input connected to GND and e.g. an ADSR as CV).
>
> Best wishes
> Dieter Doepfer
>