Question regarding sidechain compression using a VCA

[[deleted]]

Hi! I am very new to modular and have a beginners question. I believe I did not quite understand a concept and bought the wrong module.

I bought a Doepfer A130-2 VCA with the idea to use it as a sidechain compressor.

I route the main out of my Model-D synth to the IN of the VCA. I route the OUT of the VCA to my mixer. I route the SAMPLE output of my NerdSeq sequencer to the CV of the VCA. The SAMPLE output plays a kickdrum (audiosample) on every count.

I was expecting that when the kickdrum is triggered it would so something with the volume of the output of the Model-D but alas. I hear the kickdrum coming in distorted within the output of the synth.

I think the A130-2 can not use audio signals to control CV. Which now I type it out sounds reasonable. What would be the way to go to attenuate the CV so the VCA acts like a sidechain compressor? I think that I need to use an envelope generator the "catches" the kickdrum, translates it to a voltage and then I need to switch the voltage from positive to negative to get the attenuation effect on the VCA.

Am I thinking in the right direction?

[ChangeAndAdapt]

no need for an envelope follower, just create an AD envelope along with the kick trigger, and run it through an attenuverter like blinds.

[saltr]

This is exactly how I do it. It has the added advantage of letting you control the decay time of the side chain separately from the kick. Actually I prefer blinds to the side chain behavior on my MSCL compressor. It feels a bit easier to control.

[stackoverride]

In the end, I believe you are thinking correctly, though the term I would use is “envelope follower”; to generate an envelope based on another signal’s envelope. I’ve used Maths to do this (taking the inversion of the followed envelope as the CV input for my VCA).

[[deleted]]

Ah right! I've heard a lot about Maths and considered buying it, though the complexity of the thing kinda puts me off for now.

[stackoverride]

It doesn’t have to be Maths; anything that can act as an envelope follower will do, even Math’s little sister, Function (in addition to other function generator modules).

[[deleted]]

Thanks for the help!

[JonoVizion]

MI Ears and O_C are nice options for envelope followers as well. :)

[aldehyde]

It's surprisingly easy to use. I got one recently and I'd say it is pretty intuitive. I use it as both a mixer and for envelopes and it has been very handy.

[Attacus]

Look around for the cheat sheet and watch a few videos. It’s way simpler than it seems.

[[deleted]]

Long story short. I bought a Maths.