Tom drum module with integrated echo

[fredrik]

@saint_et_moudulard

I think it’s the best use to add a cv on this chip.

Well, not from an engineering perspective; the PT2399’s VCO is current controlled, and you can control it very precisely with some rather trivial circuitry. Vactrols aren’t precise at all, especially not if you just run a voltage through them, and CdS photoresistors use banned materials, but if you’re fine with that I’m not going to stop you from using it

For more on different voltage control options, see this article and this thread:

Adding CV to existing circuits

hey friends, I am working on a project (BD++) and am wanting to add CV to a parameter usually controlled by a potentiometer. here is the existing circuit: [vactolQ1] I understand since this pot is acting as a variable resistor it can be replaced with a cv source via vactrol. Is it possible to just sum them together, pot and CV? something like: [vactrolQ] is there an easier way to do this without using vactrol? opamps?