VOLTAGE CONTROLLED ATTENUATORSWhen the FET has the two resistors on the gate with a series capacitor then the distortion is reduced a lot but the attack time is very slow. The circuit from Rod Elliot that I posted (post #2) reduces distortion and is fast.
The CAD cell has slow response and we know why.
All the rest of the versions we have talked about are fast. Faster than we need.
The "slow" is a function of attack time and release time and not the speed of the gain block.
Here is the MOSFET circuit I used. In this example the sine wave is 1khz. The control changes every 10mS.
Here I speed up the sine to 10khz and the control up to 1mS.