This was discovered by accident and passed on to me. I thought I should pass it on to you. Only one Oscillator used. No Filter. The DC voltage that modulates the effect can be variable from a mod wheel, an LFO, an ADSR or whatever.
0:00 Intro
0:33 Diagram
1:15 First test. View wave folding on scope.
2:08 Turning up input signal from Oscillator.
2:59 Adding an LFO to modulate the effect.
3:43 Speeding LFO to audio range.
4:23 Adding a second VCA in series with inverted signal.
6:02 Driving dual VCA'a with LFO.
6:45 Ending.