http://www.musicfromouterspace.com/analogsynth_new/VCO20120618REV0/VCO20120618REV0.html
This is an add-on board for the MFOS VCO Core that implements the pulse/tri/sine waveform sections of Ray's design.
jbeuckm/MFOS-VCO-Shapers
http://www.musicfromouterspace.com/analogsynth_new/VCO20120618REV0/VCO20120618REV0.html
Eagle