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MIDI velocity controlling VCA output.

Posted: Tue Feb 21, 2017 6:48 pm
by Rarecomponentadsr
I'm finding that trying to control volume via midi velocity out from midi to CV unit is not very effective.
I'm taking a patch lead from the midi velocity out to the input of an attenuator and then another patch lead from attenuators output to the control input of a the VCA. The attenuator is there to control the level of the velocity signal.
However, I'm finding the results clumsy. I've tried switching off the VCAs E.G. and just using the velocity, very hit and miss. Maybe I'm approaching this wrong ?
I'm trying to achieve a touch sensitive control that creates volume levels for each note.

Re: MIDI velocity controlling VCA output.

Posted: Wed Feb 22, 2017 9:49 pm
by MC
It's the wrong approach.

You need two VCAs. Route audio through both of them in series. Route velocity CV to the first one in the chain, and route EG to the last one in the chain.

Velocity shapes the volume level, that's the function of the 1st VCA. EG shapes the contour, that's the function of the second VCA. It doesn't work with one VCA.

The other approach is to route EG CV through a VCA and use velocity CV to vary the attenuation of the EG, then route the attenuated EG to the CV input of a 2nd VCA with audio going through it.

I think the Moog VCAs can attenuate CVs, but not every VCA can.

Re: MIDI velocity controlling VCA output.

Posted: Thu Feb 23, 2017 8:28 am
by Rarecomponentadsr
Many thanks MC...now I recollect seeing this method before..I'm sure this is going to give me what I'm looking for.