Custom Effect? Does this exist?

[JohnDavisNYC]

I have an idea for a pedal that I think would be really cool, at least in my mind... I want a pedal that is JUST a VCA with one CV input and audio in and out... and true bypass (or a great buffer)... that way with something like a RobotFactory ModBox or a Moog MP201 you could have a CV tremolo, or you could lock your volume envelope to that of a drum loop, CV sequencer or even use the MP201 as a volume pedal.

I can't find it anywhere, but doesn't seem like it would be that hard to make... anyone want to build one? I don't know how, or I would do it myself... 9v VCA a possibility? Again, I'm useless on these matters.

John

[TheMutt]

Not sure on it being done before, but I'm sure you could contact Mario at Robot Factory Pedal Co. and see if it's possible.

[fightthepower]

Well I can't help you on the pedal idea specifically.. Im even more useless on these matters..

But just a thought: the moog Ringmod can get you some of that functionality.. Plug the MP into the Carrier In of the ringmod and you have cv tremolo, which you can do some fun stuff with. The MP's squarewave (unlike the ringmods built in square) had a significant volume drop, but the others all worked great and in expression mode you can manually sweep it, and get 'volume pedal'-like results. (it feels like you're manually sweeping a sine, with no volume at heel and toe down and full volume in the middle)

You seem to have lots of cool pedal idea's... you need to partner up with a builder and start brain storming!

[Swimming Bird]

It wouldn't be a terribly hard circuit to make. I think the easiest way would be to make a subtracting amplifier with op-amps using the CV as one input and your signal as the other. You'd want them on the same scale though, so you'd probably need to attenuate one or both. Of course you'd also want an logarithmic gain stage to up the CV signal and make it work as an audio taper, but I'm pretty sure you could do that with another op-amp.

Oh, and you could have sweet second mode with a summing amp instead of a subtractive one to get neat things like a positive tremolo.