Expressor Hi Pass and Optical Gating test

Expressor is deeply modified filter of the most famous Soviet synthesizer Polivoks. Unlike the ancestor, Expressor is a complete state variable filter with LowPass, BandPass and HiPass modes, which can be extremely overloaded or driven into self oscillation. On board there is a voltage controlled lowfrequency oscillator, the waveform of which is infinitely variable from ramp to triangle to sawtooth, or rectangular with variable width, similar to the way it is implemented in Korg MS20. The cut