via this auction, also on Reverb
"This Mono/Poly has been thoroughly tested, and all functions work as intended. The Mono/Poly is a 44 key "mono-polyphonic" analog synthesizer manufactured by Korg from 1981 to 1984. This model is the sister synthesizer to the Korg Polysix, with four highly stable voltage-controlled oscillators (VCOs), a 4-pole, self-oscillating low pass filter (LPF), several modulation capabilities and pseudo-polyphony (paraphony) functionality.
The four VCO's can be shared in four-voice Polyphonic mode, or linked in Unison for a versatile monophonic lead. Each VCO has its own level, tune, and waveform type control. Waveforms include triangle, sawtooth, and variable pulse wave. It has a great VCF (filter) section as well as two envelope generators (one for the oscillators and one for the filter), and there are also two individual LFO's which can be used to modulate the Pulse Width, Envelope and Arpeggiator independently.
A very flexible and fun synthesizer, other cool tricks up Mono/Poly's sleeve include chord memory and an effects mode in which oscillators have a variety of ways to be synced. The built-in arpeggiator and sequencer can run all 4 VCO's at a time or cycle through each voice per note. There's also portamento, CV/Gate, VCF and VCO mod inputs, a white noise generator, and the pitch/mod wheels can be assigned to control LFO, pitch, or the filter."
