"The Matrix-12, truly one of
the 'Monsters' of
programmable analog

Peter Forrest
The A-Z of Analogue Synthesizers

The Matrix-12 is the last flagship by the original Oberheim company. It was produced from 1985 and a small number were made to order by the "new" Oberheim in 1991. Now the model has long been discontinued and can only be found in the used gear markets at around US$2,500 to US$3,500, depending on the electronic and cosmetic conditions, with or without aftertouch ( a number of the early ones are without the aftertouch...) and any modifications (e.g. individual audio outputs) added.

Basically it is the combination of 2 Xpanders with a 5-octave keyboard and 2 modulation levers. This means that it is a 12-voice 12-part multitimbral polyphonic analog synthesizer. With 2 oscillators per voice and 12 voices in monophonic mode, one can produce probably the thickest, warmest, fattest and craziest synth sound.

As in the Xpander, each voice consists of the unique Matrix Modulation System, with 27 modulation sources and 47 destinations with user-definable routings. The total of 5 envelope generators, 5 low frequency oscillators, 4 ramps and 3 tracking parameters per voice are among the modulation elements that can provide a user with flexibility and creativity only the sky can limit.

All in all, the Matrix 12 is the culmination of Oberheim's search for the 'perfect analog synthesizer'. It doubles all the extensive programming features, MIDI compatability and sound potential of the Xpander.


Audio Sources
12 Independent Velocity, Release Velocity and Pressure (After Touch) responsive analog Voices.
Voice Control Assignment can be per MIDI Input Channel (12 maximum) or per polyphonic grouping in up to six Zones.

On-Board ("Local") Controllers
61-Note (C0 to C5) five-Octave Velocity, Release Velocity and Pressure (After-Touch) sensitive Keyboard, non-weighted.
2 Non-dedicated Modulation Levers.
2 Non-dedicated Pedal Inputs.

Voice Architecture
2 Voltage Controlled Oscillators ("VCOs")
1 15-Mode Voltage Controlled Filter ("VCF")
15 Voltage Controlled Amplifiers ("VCA")
1 FM Modulation Generator
1 Lag Processor
3 Tracking Generators
5 Digital Envelopes
5 Digital Low Frequency Oscillators ("LFOs")
1 Noise Generator

Matrix Modulation™ System utilizing 27 possible Sources routed to 47 possible Destinations in up to 20 "Modulation Pages" per Voice.
12 Permanent ("hardwired") modulation per Voice.

MIDI Implementation
Transmit and Receive Channel select independent per Voice (MIDI MONO Mode) or per polyphonic Zone.
Modes -
Mode 1: OMNI On, Poly
Mode 3: OMNI Off, Poly
Mode 4: OMNI Off, Mono
Controllers -
Indendent Controller Number select
Controllers ON/OFF select
Patch Change Commands ON/OFF select
Miscellaneous MIDI Features -
System Exclusive ON/OFF select
MIDI Echo ON/OFF select

Three 40-Character Fluorescent Displays
100 SINGLE Patch Memory Locations
100 MULTI Patch Memory Locations
"Chain" Programming Mode
Cassette Interface - FROM (input) and TO (output) ports
Trigger Input Requirements (selectable): +5V DC signal minimum, 1ms Pulse Width
Power Requirements (selectable):
North America and Japan: 95 - 120 V A.C., 50 - 60Hz
Europe: 200 - 230 V A.C., 50 - 60 Hz

Length: 38-7/16 in. (97.63 cm)
Width: 20-5/16 in. (51.59 cm)
Height (maximum, Including feet): 5-15/16 in. (15.08 cm)

Net: 33 lbs. (14.97 kg.)
Shipping: 40 lbs. (18.60 kg.)

Optional Accessories
FS-7 Sustain Footswitch
POB-X Volume Pedal
Individual Voice Outputs Update Kit