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CV Inputs
Posted: Thu Jan 19, 2012 12:52 pm
by TheStevenLasombras
Can any of you guys with actual technical info comment on how hard it would be to modify pedals with CV inputs? I'm NOT a builder, but I've been using fuzzes (and all my pedals, really) with synth gear enough lately, it occurred to me that being able to control some of those pedals' parameters with control voltage instead of twisting knobs (or moving sliders, in the case of the old POG) would be really cool.
Would this kind of mod be feasible for most (or any) pedals? OR, are there any pedals it would be MORE feasible for? Are there technical issues preventing this (beyond lack of space inside the enclosure)? Any info would me much appreciated.

Re: CV Inputs
Posted: Thu Jan 19, 2012 6:49 pm
by RR Bigman
If the parameter in question is not designed to be controlled by a voltage (VCF, VCO etc etc) then you would have to make some changes to the circuit. Using digital pots and a microcontroller is an example. There may be ways that I'm not aware of that more experienced members could explain, but as far as I know it's not exactly a simple procedure.
Re: CV Inputs
Posted: Thu Jan 19, 2012 10:09 pm
by eatyourguitar
pretty much what he said. if the pot you want to replace with CV control is already connected to V+ then its just a matter or wiring it to the jack. almost every time you have a volume control or an adjustable filter, it has audio going through a pot. the only way to do it is to remove the pot completely and use something else that can be voltage controlled. like OTA's or vactrols or opamps for filters. just vactrols or opamps for volume. I have seen a delay pedal that was modularized with digital pots and a microcontroller. it has like 5 CV inputs. if you dont need that many CV inputs, skip the microcontroller.
Re: CV Inputs
Posted: Fri Jan 20, 2012 6:15 pm
by TheStevenLasombras
Thanks, both of you. That is helpful!
RR Bigman wrote:If the parameter in question is not designed to be controlled by a voltage (VCF, VCO etc etc) then you would have to make some changes to the circuit
eatyourguitar wrote:if the pot you want to replace with CV control is already connected to V+ then its just a matter or wiring it to the jack .
Do you guys know (or know where to find out) which pedals (brand or type of effect) typically have pots connected to voltage like this? Or would it just be a trial-and-error thing, opening up each pedal to check?
Re: CV Inputs
Posted: Fri Jan 20, 2012 7:38 pm
by eatyourguitar
Its a case by case thing. If the schematic is available online, that makes it easy.