> Hello
>
> First time on this forum.
>
> I've just bought a Doepfer modular and I'm have a slight problem
> with the A101-1 Vactrol filter.
>
> Whenever I connect anything to one of the CV inputs I get a lot
> of background noise/interference. This happens even when the
> corresponding CV control is zero and even when connecting to
> sources with no control voltage output (e.g. mixer input or reset
> on LFO)- so its not CV opening the filter.
>
> Any ideas anyone
>
> Cheers
>
> Carter

That's a very unusual behaviour because zero CV should be the same as an
open CV connection. I'd recommend to return the module for repair. I have
never heard of such a behaviour (i.e. connecting zero Volt CV that affects
the sound) and have no idea what could be the reason (maybe it a problem
with a GND loop ).

Best wishes
Dieter Doepfer