A rather unusual paraphonic synth produced by Korg in the 1981-83 timeframe. In the progression of Korg's product line, it served as a bridge between the high-end, fully polyphonic PS series of the late 1970s, and the more practical voice-allocation polyphonic synths that Korg would produce in the 1980s.
The distinguishing characteristic of the Mono/Poly is that while it had a single voltage controlled filter and voltage controlled amplifier in its voice architecture, it had four voltage controlled oscillators, and a scanning keyboard which allowed up to four notes to be played at once. A voice allocation system allocated the four VCOs to played notes. Several trigger modes allowed the user to choose how the VCF and VCA, each of which had a dedicated envelope generator to control it, were to be articulated. It was also possible to put the synth in unison mode, and then tune the four VCOs to any desired intervals. A unique feature called "chord memory" allowed the user to play and capture a chord which would be used to set up offsets for the VCOs; the user could then play the chord in any desired key by playing one key to designate the root note.
A built-in arpeggiator could be clocked by either of the onboard low frequency oscillators. A CV/Gate interface was provided for external control (in unison only), plus additional control voltage inputs for VCF and VCO modulation. The synth came equipped with Moog-like pitch and mod wheels and a 44-note, F to C keyboard.