Soft A VCA

Soft A VCA

This VCA models the characteristics of soft clipping distortion present in analog VCAs. It isn’t a model of any particular type of VCA, but it does sound very warm.

Note: The “A” just refers to the fact that there will be more soft clip VCAs like this one that tweak the transform formula.


Input Signal Range Notes
input-audio -1 to 1 Audio input
input-modulation 0 to 1 Modulation input

Output Signal Range Notes
audio-output -1 to 1 Audio output


Knob Function Notes
knob-overdrive Overdrive Amount of soft clipping distortion
knob-feedback Feedback Amount of internal feedback
knob-level Level Maximum modulation input level

Version History

Revision File Date Notes
1.0 Soft A VCA.audulus (20.8 KB) 5/30/18 Initial upload


Revision File Date Notes
1.0 Soft A VCA Bass Comparison Demo.audulus (233.7 KB) 5/30/18 A demo to compare the sound of the VCA vs. a digital linear clean VCA
1.0 Soft A VCA Filter Demo.audulus (367.6 KB) 5/30/18 A demo using the K35 LPF in a more typical subtractive synth layout

Why does "((x>=1)*0.5+(x<1)*(x>0)*(-0.5*x^2+x)+(x<0)*(x>-1)*(0.5*x^2+x)+(x<=-1)*-0.5)*2" sound so much like a filter?

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Well if it’s cranked up, it’s adding harmonics, and as you back it off, it is subtracting them? Is that maybe what you’re hearing?

Quick hint - use backticks “``” between expressions like that to get pretty formatting like this:


or the double dollar signs for even prettier versions

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Wait, how does the double dollar signs work?

Another beautiful tool. Stoked on the sound of this @biminiroad. I also like how you set up the sequencers with 1 running at 1/32.

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Thanks! Glad you dig :slight_smile: The underlying distortion is pretty cpu efficient too.

Yeah! That’s a technique I like to use to give a little motion to the random sequencer. Basically the random sequencer is a sort of random arpeggiator and the second sequencer clocked at 1/32 you can think of as the note being played.