When Korg released the Polysix in 1981, they pulled off something remarkable: they made a genuinely playable six-voice polyphonic synthesizer for roughly a third of what competitors were charging. The trick was elegant simplicity—one oscillator per voice instead of two, but compensated with built-in chorus, phaser, and ensemble effects that gave it a richness that belied its streamlined architecture.
The synthesis engine centers on a single VCO per voice with a dedicated suboscillator and pulse-width modulation, feeding into a warm 24dB lowpass filter based on classic SSM chips. You get one ADSR envelope and one LFO (sine waveform) for modulation, plus a filter with controls for cutoff, resonance, envelope amount, and keyboard tracking. The envelope generator includes a unique centre-zero control that lets you flip between normal and inverted shapes. All six voices route through the effects section, where you can dial in chorus, phaser, or ensemble—each with adjustable intensity using bucket brigade analog delay circuitry. The 61-key keyboard includes chord memory and an arpeggiator with up/down and up/down/up modes, plus external pedal support. You get 32 editable patch memories and a cassette interface for backup.
The Polysix earned its reputation quickly and has held it for decades. Players consistently praise the filter character and the way those effects transform a single oscillator into something lush and dimensional—particularly the ensemble effect, which recalls vintage string machines. The straightforward one-knob-per-function layout means you're not buried in menus, and the arpeggiator is genuinely musical. Common observations from long-term users note that the original internal battery can leak if the unit sits unused for extended periods, but the core circuitry is solid and built to last. On the market today, original units remain sought-after, and the Polysix's influence on affordable polyphonic synthesis was substantial enough that it's still referenced as a benchmark for warm, characterful analog sound.
