Korg PS-3100 / PS-3200 / PS-3300

The Korg PS-3100 (1977), PS-3200 (1978), and PS-3300 (1977) — Korg’s “PS series” — were among the first fully polyphonic analog synthesizers, using a divide-down oscillator bank of twelve master VCOs (one per pitch class) feeding 48 fully independent filter, envelope, and amplifier chains, so every key had genuinely independent articulation rather than the shared or time-multiplexed voices typical of the era. The base PS-3100 had no patch memory; the PS-3200 added extra oscillator resources per note and 16 recallable patch memories; the PS-3300 was the flagship, effectively three PS-3100 voice sections combined into one large semi-modular instrument with internal patch points, played from a detached remote keyboard. All were large and expensive — only 30–50 PS-3300 units were ever built — and were used notably by Vangelis and Jean-Michel Jarre.