[sdiy] Experimental VCA RFC

[René Schmitz]

Hi Jerry,

Interesting concept. How does the output signal look like waveform-wise. 
I.e. how much distortion? Offsets?

I would have thought that such a circuit could work as a switch/gate but 
not for proportional control.

What you should be aware is how much reverse voltage the C-E of your 
opto can stand. Sometimes only 5-6V. Which would be your maximum amplitude.

As others have pointed out you can linearize the control by a servo loop.

Cheers,
  René