I probably got you wrong but if you insert one audio into Signal In and another one into CV In you'll get AM which resembles ring modulated sounds.

You might want to patch the 2nd audio source into an External Input module and use it's Envelope Follower output for the CV In of the VCA.

But then, I might got you wrong.

Best, Ingo

--- In Doepfer_a100@yahoogroups.com , Richard Scott <richard_scott@...> wrote:
>
> Hi
>
> I am interested in using one audio signal to determine the amplitude of
> another. I think an AC coupled VCA or mixer is the way to do it What
> VCAs or VC mixers in eurorack format can offer this facilty
>
> Richard
>