audiobriefs
8:40in productionCh. 1 · How Polyphony Actually Works/ 8:40 · ceiling 15 min
Synths & drum machines

Korg PS-3100

Korg

The PS-3100 gives every key its own synth — but forces you to tune it by hand, every time.

The Korg PS-3100 is a rare (600 units), 30kg, 48-voice analog synthesizer from 1977. It uses 12 divide-down VCOs to drive 48 independent voice circuits — one VCO, VCF, VCA and EG per key. Its warm LPF and 3-band resonator enable rich formant and phase effects. LFO1 reaches audio rate and delivers AM up to ring modulation. One EG is polyphonic; the other is universal and paraphonic. Twelve intonation scaling controls allow non-equal-tempered tuning. It has no patch memory.

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Chapters & takeaways4
  1. 1:02
    How Polyphony Actually Works

    48 voices, not 48 oscillators — 12 divide-down VCOs feed fully independent voice circuits.

  2. 2:35
    Where the Sound Comes From

    Warmer filtering and a 3-band resonator make it uniquely rich for formants and phase shifts.

  3. 4:19
    Modulation and Envelopes

    One audio-rate LFO does AM up to ring modulation; one EG is polyphonic, one is paraphonic.

  4. 5:26
    What You Lose to Get It

    Twelve intonation controls let you abandon equal temperament — but there is no patch memory.

Worth your time?

Yes. Use the whole thing.

4/ 5
What works
  • per-voice filter and amp control
  • formant generation via resonator
  • audio-rate AM and FM
  • intonation flexibility
What does not
  • support preset recall
  • offer dual-VCO per voice
  • fit in a backpack
  • scale to live performance
Use it if
  • studio composers
  • sound designers building evolving pads
  • researchers of analog polyphony architecture
Skip it if
  • performers needing instant recall
  • modular users seeking flexible routing
  • anyone without a freight elevator
The written brief2 min read

What it is and what it was built for

The Korg PS-3100 is a 48-key, 48-voice analog subtractive synthesizer built in 1977. It was built for studio composers and institutions needing stable, multi-voice analog polyphony with timbral depth — not for touring or quick sound design.

How it works, in terms a player would use

It uses 12 divide-down VCOs feeding 48 fully independent voice circuits — one VCO, VCF, VCA and EG per key. The LPF is warmer than Korg’s MS-series. The 3-band resonator creates formants and phase effects. LFO1 runs up to 1 kHz and delivers continuously variable AM up to ring modulation. One envelope generator is polyphonic; the other is universal and paraphonic. Twelve intonation scaling controls adjust tuning away from equal temperament. There is no patch memory.

What it does better than anything else

It delivers richer polyphonic analog texture than any other 1977 synth by giving every key its own VCF, VCA and EG — not just a shared filter or amp. Its resonator section produces vocal-like formants and shifting phase effects unmatched by contemporaries with fixed filters.

What it does badly

It cannot store sounds. It offers only one VCO per voice — no oscillator mixing, no sync, no cross-modulation beyond LFO1’s AM/FM. Its paraphonic EG limits expressive control across held notes. Intonation scaling requires manual adjustment per patch and offers no recall.

What people made with it

No sources state what people made with it.

Who should use it, and who should not

A studio-based sound designer or composer who values hands-on, per-voice filter and amp control and needs formant-rich pads or evolving phase textures should use it. Anyone needing patch recall, portability, or dual-VCO thickness should not.

Is it worth your time

It is worth your time only if you need 48-voice analog polyphony with formant shaping and audio-rate modulation in a single instrument — and can move and maintain a 30kg unit with no presets.

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