Triple discrete exponential VCA
This is a DIY VCA made with discrete transistors, 20 of them per channel, in an operational transconductance amplifier arrangement similar to the circuit inside an LM13700. It has a rarely-seen pure Class B output stage, with compensation against crossover distortion.
"Discrete" amplifiers are mostly mumbo-jumbo; to be quite frank, you get better performance on almost any objective measurement by using ICs. If you want a clean, noiseless VCA that doesn't colour the signal or feed through the control voltage, then this one is not for you. Nonetheless, the all-discrete amplifier is fun to build, and its unique distortion may add something interesting to a synthesizer patch. It's meant to be a VCA that you can hear.
Exponential response curve and AC-coupled output make this module best suited for audio rather than CV purposes.
Module is available as a DIY project only.
No info about availability.submitted May 14th 2016, 15:58 by mskala | last Change Sep 28th 2017, 04:18 by mskala