Black Polivoks VCF V2

A close take on the filter of the Formanta Polivoks synthesizer, on the original Russian K140UD12 chips, with band-pass (6 dB/oct) and low-pass (12 dB/oct) modes. Updated for the modular: independently buffered inputs, an extended cutoff range, click-free mode switching and an output stage that undoes the signal inversion.