I recently noticed that if I connect my Digisound 80-6L or
EFM VCF7 to the A-131 and use a short attack I get loud
clicks from the VCA, quite different (and a whole lot
louder) than the short click I'm used to getting with
zero attack.

Could this be due to some interaction
or bad decoupling in these two filters

I also have the EFM VCF6 which is fine and neither do
I get it with the A-120 or A-121, nor with Ken Stone's
Synthacon filter.

Louis