Oberheim · Analog polysynth · Early MIDI era
Oberheim made the Matrix-12 from 1985 to 1988, and the company's own history still calls it one of the most versatile analog synths ever built. It's the 12-voice keyboard version of the Xpander, which came a year earlier, with two oscillators per voice and a 61-key keyboard with velocity and aftertouch. Oberheim's Matrix Modulation lets you route sources like LFOs, envelopes, velocity and aftertouch to almost any part of the sound. Each voice gets five envelopes and five LFOs. The filter is multimode, covering low-pass, high-pass, band-pass, notch and phase shift settings, and it's built around a Curtis chip. It holds 100 patches and can split or layer sounds. The Orb, Vangelis, Depeche Mode and Technotronic all used one. There's a lot inside, so the state of the voices and controls matters far more than looks. Buy one that's been serviced, and get a video of all 12 voices before you pay.
It shares its voice design with the Xpander, whose owners report failing encoders, voices that fail autotune and power transformer trouble. With 12 voices there's twice as much to go wrong, so a full demo matters.
Buying guide
Only three Matrix-12s are for sale, so the $18,500–19,625 band is three asks and isn't a market read. We'd buy the US dealer's unit titled Pro-Refurbished at $18,759 delivered, or save about $470 on the German one titled Completely Overhauled if you're happy to handle import fees and a voltage check. Ask for a video of all 12 voices on one patch and an autotune run with no voice errors, and ask whether the power supply has been looked at, since it shares the Xpander's encoder, autotune and transformer faults. It's a big, heavy keyboard, so confirm double boxing or a road case plus insurance, and read the recent feedback before dealing with the 87% seller asking $20,490 delivered.
$18,286.00est. delivered
The lowest ask at $18,286 delivered, titled Completely Overhauled. It ships from Germany, so allow for import fees and check the voltage plate, since a 220-240V unit needs a step-up transformer or an internal change on US mains.
Oberheim Matrix 12 / Excellent Condition / Completely Overhauled
$18,759.47est. delivered
Titled Pro-Refurbished by a US vintage synth dealer, for about $470 more than the German unit, and it's already in the US. Ask what the refurb covered, power supply included.
Oberheim Matrix-12 Synthesizer Keyboard *Pro-Refurbished* VINTAGE SYNTH DEALER
Delivered prices include shipping as eBay quoted it to a US address on Oct 5, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Snapshot
Checked . Some may have sold.
Delivered prices include shipping as eBay quoted it to a US address on Oct 5, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Serviced$18,286.00est. delivered
$17,948.35 + $337.65 shipping
Buy It Now$17,948.35
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Good buy
Titled Completely Overhauled. Ships from Germany, so check the voltage plate.
Seller: phunkydesk
100% positive
Refurbished$18,759.47est. delivered
$18,524.99 + $234.48 shipping
Buy It Now$18,524.99
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Good buy
Titled Pro-Refurbished by a US vintage synth dealer. Ask what the work covered.
Seller: 123synthland
100% positive
Used$20,490.00est. delivered
$19,995.00 + $495.00 shipping
Buy It Now$19,995.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Check the seller
87% feedback, asking the most at $20,490 delivered. Read the recent feedback first.
Seller: hbwk5_5
87% positive
Prices change daily. The live eBay search shows everything listed now, including anything new since Oct 5, 2026.
See every listing on eBay ↗eBay search
Oberheim · Analog polysynth
Oberheim Xpander
1984–1988 · 6-voice polyphonic
Asking $5,475–$7,125 on eBay
Oberheim · Analog polysynth
Oberheim OB-8
1983–1985 · 8-voice polyphonic
Asking $9,300–$11,225 on eBay
Sequential Circuits · Analog polysynth
Sequential Prophet VS
1986–1987 · 8-voice polyphonic
Asking $7,075–$8,675 on eBay
Yamaha · Analog polysynth
Yamaha CS-80
1977–1980 · 8-voice polyphonic
Moog · Analog polysynth
Moog Memorymoog
1982–1985 · 6-voice polyphonic
Asking $9,550–$15,500 on eBay