1) changed CVs to eurorack standard 1V/Oct (original has inverted CVs)
2) made all CV ins buffered in order to eliminate crosstalk and undesired detune (very few DIY kit producers buffer CV ins - mostly they are just summed on resistors). As result the VCO is surprisingly stable and tunes well.
3) made optional adjustments to output signal amplitudes and offsets - you can have the original output signals (they are totally different waveform to waveform) or make them standard 10Vptp
4) original Polivoks has interesting peak in the triangle waveform - we introduced optional filter to eliminate it or leave as it is
5) we significantly updated pulse wave circuit and introduced PWM - it sounds insanely great!
10 pages building and caibration manual contains ideas and hints for more modifications, if you are not happy with the standard Polivoks VCO. Those, who intend to build both VCOs and Erica Synths Polivoks Modulator, might be interested in DIY Mixer kit also.
Her's waveform comparison! In my case triangle peak is partly filtered out (see schematics for mods). The far right waveform is actually dynamic - square wave with PWM from the Polivoks Modulator LFO.
And this is whole beauty - 2 VCOs + the Mixer!