Korg Polysix (1981–1984)

Six voices of dark, warm analog with a chorus that became the sound's fingerprint.

Overview

The Korg Polysix - also written Poly-6, PolySix, or Polysix depending on the source - landed in 1981 as Korg's answer to the wave of affordable polyphonic synthesizers flooding the market. It was manufactured in Japan from 1981 through 1984, and in that short window it became one of Korg's best-selling synthesizers. The original price was $1095, which put it right against cheaper polyphonic competition like the Roland Juno-6 and Juno-60, according to vintagesynth.com.

The Polysix wasn't a spec sheet arms race. It was a mono-timbral 6-voice analog instrument with one VCO per voice plus a sub-oscillator, a 49-note keybed and a 24dB/oct low pass filter. On paper that looks modest next to the dual-oscillator behemoths of the era. Owners describe it as something else entirely. One gearspace.com user put it bluntly: "The Polysix is the poor-man's Prophet-5." That's not a knock. It delivered a big portion of the flagship experience at a fraction of the cost, with a character all its own.

People feel strongly about this machine. "It's a very underrated synth," one owner insists. Another declares it "King of the string pads." Forum threads and period commentary agree that the sound punches far above the price tag, even if the build quality and keybed remind you where the money went.

Key Features

Single VCO Plus Sub-Oscillator Architecture

Each of the six voices had one VCO with a sub-oscillator underneath. There was no second detunable oscillator to fatten things up. The available waves were sawtooth, PWM, square, and the sub-oscillator itself. This was a deliberate economy. Fewer oscillators per voice meant lower cost and better tuning stability, but the thickness had to come from elsewhere. It came from the filter and, most famously, from the effects section. The sound is lean at the source and sculpted on the way out.

24dB/Oct Low Pass Filter

The filter is where the Polysix earns its reputation. The 24dB/oct low pass design gives the liquid, four-pole sweep that analog enthusiasts chase. It can go from polite string pad to snarling, aggressive lead without changing patches. Just open the cutoff and let the resonance take over. The filter is also self-oscillating, so it can produce its own tone when pushed.

Poly, Unison, and Chord Memory Modes

Beyond the standard poly mode, the Polysix offered Unison — stacking all six voices for a fat mono sound — and Chord Memory, which let you hold a chord shape and play it from a single key. These performance modes turned a six-voice keyboard into something far more flexible on stage. Chord Memory in particular was a gift to live players who wanted big one-finger voicings without a sequencer or external brain. The modes are simple, immediate, and exactly what a working musician needed in 1981.

Built-In Chorus, Phaser, and Ensemble Effects

The built-in effects section - chorus, phaser, and ensemble - became the instrument's signature. "It's got the best-sounding chorus of any synth, IMO," one gearspace.com owner says, and that opinion is widely echoed across the vintage synth community. The ensemble effect is the sound on countless records from the era: wide, swirly, slightly detuned motion that makes a single VCO per voice sound like far more. The effects turned the Polysix from a competent budget poly into a textural powerhouse.

Built-In Arpeggiator

The Polysix also packed a built-in arpeggiator. Combined with the chord memory and the effects section, it made the Polysix a self-contained performance instrument. You could hold a chord, set the arpeggiator running, and layer the ensemble effect on top for instant, evolving textures. For a synth in this price class, that was a lot of capability in one box.

Historical Context

The Korg Polysix was introduced in 1981 and manufactured in Japan through 1984. It was aimed squarely at the market for cheaper polyphonic instruments, competing with the Roland Juno-6 and Juno-60, according to vintagesynth.com. Affordable polyphony was still young, and the Polysix arrived with six voices, built-in effects and patch memory.

It also carried 16 programs or patches, which could be stored and recalled. Many budget polysynths of the time were preset-only or required manual tweaking. The Polysix let players save their sounds, even if the battery-backed memory would later become a notorious failure point.

The gearspace.com community has a saying about this keyboard: "Korg Polysix = King of the string pads." That reputation dates to the early 1980s and has only grown since. The string sounds, animated by the ensemble effect, with that analog warmth, became a benchmark that later digital instruments spent years trying to replicate.

Collectibility & Value

The Polysix has held up in the collector market. One auction listing via worthpoint.com puts its collector's value at $1000 to $1200, essentially holding its original $1095 price tag four decades later. The price estimates ($1095 original vs. the $1000 - $1200 auction range) reflect different contexts, but the Polysix has not depreciated. A period review in Polyphony magazine noted the Polysix's value proposition relative to other six-voice polyphonic keyboards of the era (Polyphony, June 1983, p.41).

Owning one comes with caveats. The most notorious issue is the battery-backed patch memory. When the internal battery dies, you lose your patches. One gearspace.com owner warns plainly: "Dead battery = lost patches - a common issue." Replacing the battery is the first thing any new owner should do. The other maintenance items are predictable for an instrument of this age: "Need to recap the power supply - and also the keyboard contacts need cleaning," one forum user advises.

None of these issues are deal-breakers, and the vintage synth community has well-documented procedures for each. A Polysix that's been properly serviced, with a fresh battery, recapped power supply and cleaned contacts, is a reliable instrument. One that hasn't is a project.

The forum consensus is that the Polysix remains undervalued relative to its sound. "It's a very underrated synth," one owner says, and the market data supports that view. You pay roughly what it cost new and get six voices of analog character and one of the best chorus effects ever built into a synthesizer.

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