The Oberheim Matrix-6 arrived in 1986 as a more accessible entry point into the Matrix family — a lineage that began with the legendary Xpander and Matrix-12 — and it quickly earned a reputation of its own. Built around the Curtis CEM3396 chip, each of its six voices runs a pair of digitally controlled oscillators through an analog low-pass filter with two VCAs, three envelope generators, two LFOs, and two ramp generators per voice. What set the Matrix series apart from the competition was its Matrix Modulation system: a virtual patching architecture that lets you route virtually any modulation source to virtually any destination, giving it a depth and flexibility that most of its contemporaries simply couldn't match. It's a synth that rewards patience and exploration, and one that continues to turn up in serious analog rigs decades after it left the factory.
This particular unit is, frankly, one of the finest examples of the Matrix-6 you're likely to find. Single previous owner, recently serviced with a fresh patch memory battery, and no other modifications or repairs — it's as close to original spec as it gets. Cosmetically it presents in outstanding shape for a synthesizer approaching 40 years old: all of the panel printing is crisp and fully legible with no fading, the keys show no yellowing, and both the top and rear panels are clean and intact. The only cosmetic note worth flagging is some minor scratching on the bottom of the unit from being moved over the years — hardly surprising, and nothing that affects the instrument's presentation or performance in any way.
Functionally it's as solid as it looks. All 61 velocity-sensitive keys play cleanly with no dead, stuck, or sluggish notes. All six voices come through cleanly with no dropouts or tuning irregularities — chords are robust and full in the way only a well-maintained vintage analog polysynth can deliver. MIDI in/out/through are all operational, all membrane buttons and the data slider function correctly, and there's no hiss, hum, or noise at either output. The pad sounds are lush and warm, the keyboard sounds bright and articulate, and the textural and ambient capabilities are rich in the way you'd expect from a high-end 1980s analog instrument. It's a genuine joy to play — equally at home in the hands of a collector looking for a pristine example or a player just discovering what vintage polyphonic synthesis has to offer.
Comes with the original power supply, the original Oberheim sustain pedal, and a heavy-duty Calzone flight case.
Spec sheet
- Make: Oberheim
- Model: Matrix-6
- Production years: 1986-1988
- Country of origin: USA
- Type: 6-voice polyphonic analog synthesizer
- Keyboard: 61 keys, velocity sensitive
- Oscillators: 12 DCOs total, 2 per voice (CEM3396)
- Filter: Analog low-pass filter per voice (CEM3396)
- Voices: 6, each with 2 DCOs, low-pass filter, 2 VCAs, 3 envelope generators, 2 LFOs, 2 ramp generators
- Modulation: Matrix Modulation system
- Memory: 100 user patches
- MIDI: In, Out, Through
- Outputs: 2x 1/4" (main and secondary)
- Battery: Patch memory battery recently replaced
- Modifications: None
- Service history: Patch memory battery replaced; no other repairs
- Condition: Very Good Plus
- Includes: Original power supply, original Oberheim sustain pedal, Calzone flight case
Shipping
Ships carefully packed and insured for full value.
International buyers are welcome — please contact us for a shipping quote before purchasing.
Heavy or oversized items may ship freight — we will confirm method and cost before proceeding.
About Mill River Music
Mill River Music is an independent, human-powered music shop located in downtown Northampton, MA, run by a team of players, enthusiasts, and certified repair technicians. Every piece of used gear we sell is personally inspected, tested, and set up before it ships — we don't list it until we'd be happy to play it ourselves.
As Martin and Taylor certified techs, we hold our guitar work to a high standard, and we're committed to full transparency about the condition of everything we sell. No surprises.
When you buy from Mill River, you're supporting an independent local business that genuinely cares — about gear, about players, and about doing things right. We're here every step of the way. Reach out anytime.
