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

Peter Forrest
The A-Z of Analogue Synthesizers (Susurreal Publishing)

A synth of such magnitude it needs two reviewers...
About two years ago my mate Dave showed me his Matrix-12, and I instantly hatched a plot to kill him and own it. The Matrix-12 marks the crest of the analogue wave, before the DX7 and D-50 brought the whole thing crashing down. The concept is simple, one synth capable of reproducing the power of 12 good-sized modular systems, with 100 memory slots and full MIDI implementation. Want one yet?

If you want my body
The Matrix-12 is a 61-note synth with three big LCDs, six value knobs and about 60 switches on the front panel. Internally, it is 12-voice polyphonic and 12-part multitimbral, each part responding to its own MIDI channel. Each voice provides two big fat VCOs (offering triangle, saw, pulse, and noise waveforms), one 15-mode VCF (offering various low pass, high pass, band pass, notch and phaser types, all complete with resonant squelch), five LFOs, five envelope generators, 15(!) VCAs, and one FM modulation generator for oscillator sync and cross-mod madness.

There's also a lag generator (a sort of portamento that can be applied to anything, not just pitch), three keyboard-tracking generators, four ramp generators (a very simple two-level envelope) and, finally, one noise generator. And that's just one voice. There are 12 inside here! All this sound-creating muscle is useless without an equally powerful control system, and to this end Oberheim came up with the 'Modulation Matrix' from which the machine takes its name. This system enables 20 connections per voice between virtually any parameters. For example, to increase the speed of an LFO with time, select LFO speed as the destination and a slow attacking envelope as the modulator. It seems an easy concept but when there are 20 of these routings going on at once, it is impossible to program with total predictability.

This is both the best and worst thing about the Matrix-12. On the one hand there is virtually nothing it can't do, on the other you might actually die of old age before you work out how. A confident programmer can produce endlessly evolving sounds of breathtaking quality, but more nervous tweakers may be sucked into a nightmare world of noise.

It can't all be down
Other failings only amount to griping, but they bear mentioning. The parameters' software control doesn't allow the precision and smoothness of an all-analogue design, the LFOs can't reach the blistering speed of some true modulars, and the memory can only be backed up to tape or as SysEx data. Worst of all, the back panel only provides a single stereo out.

Even with these drawbacks, the Matrix-12 can hold its head high alongside elite instruments like the Roland System 700, ARP 2500 and Moog 55. So should you buy one? Well, as I was inching towards Dave with a knife the other day, he mentioned rumours of a Nord Virtual Modular in the pipeline, and so he's bought himself some more time.

Price and availability
When Oberheim released the Matrix-12 in 1985 the ?,500 price-tag put it beyond the reach of most mortals and, to be honest, not a lot has changed. If you can find one (a quick ring round the analogue specialists revealed that none have changed hands for about 12 months) then you can expect to pay out somewhere in the region of ?,200-?,700.

Past masters
Matrix-12 owners include, or have included, The Orb, Frankie Goes To Hollywood, Yello, Propaganda, Harold Budd and Emerson Lake & Palmer. The Oberheim family of synths began in the early 70s with the Oberheim Two, Four and Eight Voice synths, pure analogue monsters beloved of both The (late) Grid and The Shamen. They were followed by classics like the OB-X and OB-8, two of the earlier memory-equipped polysynths. The Matrix family of synthesizers grew out of the Xpander module, Oberheim's attempt at making a patchcord-less modular synth. The Matrix-12 is essentially two Xpanders with a keyboard bolted on the front.

The Matrix-6, despite its name, is not half a Matrix 12, but rather a bitimbral budget version, with DCOs instead of VCOs, an awkward keypad editing system instead of knobs, and reduced modulation possibilities.

Although not in the same league as its bigger brother, it is a quite complex synth, and can still be bought new today, masquerading as the Matrix 1000. The main differences are the total absence of front panel editing, rather compensated for by the addition of 1,000 presets and the ?99 price tag. Both software and hardware editors are available for tweakaholics.

Matt Thomas / Dave Knowles
Future Music: Issue 61 (Oct 1997) (Samples from the free CD)

Oberheim's Matrix 12 is a legendary analog synthesizer from the mid-eighties that is still the king of analog sounds. One of the fattest, roundest, pleasantly analog synthesizers around! It's long been known for creating some of the thickest and best analog pads, sweeps, buzzes, basses and textures. It features Matrix Modulation for extremely wild virtual patching for almost unlimited range of sounds and modulation capabilities!

The Matrix 12 is similar to the Xpander and the lighter Matrix 6. But the Matrix 12 is much fatter and more programmable than either. Every control can have an effect on some other parameter thanks to Oberheim's flexible design. For example, there are 15 types of LFOs and VCAs per voice! And there's plenty of diagrams drawn out on the front panel of the synth to help you figure out some signal routing. This is not a synth for the beginner.

Vintage Synth Explorer

The Oberheim Matrix-12.. a DIFFERENT kind of review of one of the most expensive Analog polys of it's time and and still so on the secondhand market, lets take a look at what it's made of, what it does and how it sounds..

as most people know, it's basically the guts of two Xpanders in a bigger box with a keyboard on, 12-note polyphonic, 12-part multitimbral, it loses the individual outs of the Xp (was available as a factory extra and not hard to fit today) and the CV/Gate in/outs, boasts the famous Oberheim "Matrix-Modulation" and 15-type multimode filters, what most people don`t know is that it is a classic example of Oberheim making a silk purse out of a whole bunch of sow's ears.

Each Xpander/M12 voice is based on the low cost Curtis 3372 combined VCF/VCA also found in the budget Sequential Prophet-600 and Akai AX80, there is enough prejudice for both of these machines to put people off but when you see that the M12 doesn't even have the expensive Curtis 3340 VCOs of the P600 but instead another low cost Curtis chip, the 3374 dual VCO you really start to wonder. top this off with six cheap carbon rotary encoders for editing, "no cost" Software envelope generators, three "Avery cash register" readouts and a shoddy budget Panasonic keyboard action and you wonder how they'd dare charge ?500 for the thing without getting lynched!.

Just as Oberheim managed to get the rough and gritty 3340/3320 curtis chipset to sound massive, fat and wonderful in the OB-Xa and smooth and sweet in the OB8, they really went overboard with the Xpander and Matrix-12 to create probably the most complex, programmable virtual modular Analog polysynths ever from the cheapest, shoddiest off the shelf components of the time (released 1984/5). after extensive use and familiarity of both the Xp and M12, I would call it total bleedin' miracle.

Sonically these machines aren't as fat, punchy or powerful as the OB-Xa, but what they lose in sheer welly they make up for in smoothness, warmth and utter complexity and are the First Oberheims since the clunky SEM based 4-voice and 8-voice polyphonics to have multimode filtering. the software engineers screwed the tits of those cheapo 3372s to provide fifteen types of filter including phase filters and combination filters as well as the usual low/hi/band pass types in various "poles", due to Oberheim's painstaking design and attention to detail those cheap Dual VCOs sound as sweet as a nut and the routings for them for FM, sync etc are superb. 5 EG's per patch although not the fastest on earth are flexible and modulatable from within the 27 source, 47 destination, 20 patch-cord mod matrix. there are tracking generators, ramp generators 5-LFOs and more VCAs than you can shake a whole friggin' wood pile at. there is still no virtual analog which even comes close for complexity.

Reliability never was a real problem, but the DAC can go (found in a scrap OB8 near you) and there are bugs in the M12's software which can cause grief with stuck MIDI notes on really fast lines (the Xpander doesn't seem to suffer). if the mains transformer goes you're in trouble (rare) and the CPU in the M12 is apparently a non-standard part unlike the Xpander. the Rotary 'twiddlers' are hard to find and wear out due to their carbon design but we're looking into readily-available replacements.

MIDI is excellent for the year, being fully multitimbral and multipatch mode provides the UNISON mode as well as the usual split, layers etc. anything from 12-note poly on 1 channel to 12 parts monophonic with all inbetween make for flexible setups, you can also fake OBX or CS80 Wonkiness and even "wavesequencing" here by having each voice play a different patch (or the same patch programmed slightly different and saved in 6 or so locations), the only fly in the ointment being that you can't change the individual patches from your sequencer on the different parts like a modern synth (or a CZ1000 for that matter) so those 100 performance memories will come in useful. Patch dumping is brilliant, you can send all patches, all multis, or just ONE and even choose where you want it to load back into when you redump it, great for collating a "best of matrix" from the internet's large XP/M12 resource of patches. all parameters can be tweaked over MIDI via Sysex controllers so warping your patches in a realtime perfor Both the Matrix-12 and Xpander take the expression "greater than a sum of it's parts" to total extremety bordering on preposterous, how OB got a pile of cheap rubbish to sound this good is completely beyond comprehension. Sequential cheated with the Prophets 600 and T8 by using the superior 3340 VCOs and neither get even close to an Xp or M12 for sound, refinement and complexity and the T8 cost as much as the M12, it's just that in the T8 you can see where the money has gone, in the Matrix-12 it's hidden in those beautifully programmed ROM chips and the circuit design. the Matrix should have been 16-note poly and the Xpander 8-note, the cost to have done this would have been minimal especially if you take the original shop prices. shame.

Comments About the Sounds: Smooth but still 'live'

Neil Bradley

I first saw it when I was probably 20-21 and just starting out as a keyboard player. At the time it represented the absolute Rolls Royce of synthesizers. There was no comparison, and to many people it still is the best analogue synthesizer ever made. For a non-modular system it is extremely deep, the modulation technology on it is extremely complex. The sound of it is glorious, it has the best filters and the best oscillators. They are very sophisticated filters for the time -- you get notch filters and phase filters and comb filters, and all that back in the days when normally you would have been lucky to get more than one resonant low pass filter. So for all those reasons, and also the multitimbrality of it, it was a revolutionary thing at the time.

Marius de Vries
Sound On Sound (September 1998)

The Oberheim Matrix-12 is THE synthesizer I have always wanted since it was released in 1985. Fifteen years later I pulled the trigger and bought one.

Everything I read about this instrument is true. It is absulutely mind-blowing. First, the physical aspects:

The Matrix-12 is the deepest synthesizer I know of with three bright vacuum flourecent strips that display all the information you need to program this mama. On the left panel is a row of 12 audio output jacks. This is a modification that's easy to install. Directly in the center just above the keys are six rotary knobs for value editing. Overall, It's an extremely COOL looking synthesizer that just looks EXPENSIVE.

The sound: WHOA. The sounds the Matrix generates are not of this planet. Strings are wonderful. Brass is punchy, pads are amazing... Want a haunting phased string sound? Take a conventional string patch and route it through the "3 phase + 1 low" filter mode. Then crank up the resonance and select an LFO to modulate the filter frequency. Amazing.

The programming possibilities are endless. I've owned mine for over 6 months now and I still am learning things it can do.

The Matrix-12 is the most advanced and powerful synthesizer ever produced. No wonder it has retained a $3k+ market value for the last 12 years. Professionals know what this baby is all about.

Ryan Day

The Xpander and Matrix 12 are 6 and 12-way polytimbral with fixed voice allocation. And in terms of sound, they eat the lower-cost Oberheims, and everyother analog synth on the market, for lunch.

(Biased? Me? Nah.)

EMUSIC-L Digest Volume 13, Number 4

The incredible Oberheim sound with absolute control.

The Matrix 12 is the culmination of Oberheim's search for the 'perfect analog synthesizer'.

The Audio Playground Synthesizer Museum

This is the ultimate analog synthesizer.

Imagine twelve voices, individually programmable with that famous Oberheim sound. Add the most versatile patching system ever developed, controlled by three computers working in parallel. Control this unbelievable capability with a velocity keyboard that can be split into six overlapping sections. Add the most sophisticated MIDI Interface ever developed, and you'll begin to get some idea of the awesome capability of the Oberheim Matrix-12.

Based upon the same revolutionary technology as the Oberheim Xpander synthesizer, the Matrix-12 has been designed to be the ultimate complete professional synthesizer. Because of its twelve voices and vast programming capabilities, the Matrix-12 can replace several more conventional synthesizers in an electronic music system. And because of the unprecedented sophistication of its keyboard and MIDI Interface, the Matrix-12 is ideally suited for use as a master controller in multiinstrument environment.

One of the most powerful features of the Matrix-12 is that each of the twelve voices can have a different sound. The machine can be split into six sections called Zones, each playable from the keyboard, from other MIDI devices, or any combination. What this means is that several of the matrix-12's voices with different sounds can be played from several parts of its keyboard, while other voices with other sounds are controlled by a MIDI sequencer, and the remainder of the keyboard controls another synthesizer, ALL AT THE SAME TIME. And all this complexity can be stored in one of the 100 MultiPatches, and be recalled at the touch of a button.

MASTER KEYBOARD The Matrix-12s five-octave, long-throw velocity keyboard responds to every subtlety of your touch, yet is light weight for ease of portability There are selectable velocity scales to tailor the response of the keyboard to your individual playing style, for the keyboard as well as for external MIDI controllers.

Naturally, the Matrix-12 keyboard responds to after-touch pressure as well as attack and release velocity. But unlike other synthesizers, these signals can be used to control almost any parameter of each voice -Volume, Filter Frequency or Resonance, Envelope times, FM Amount, Vibrato, Detune, LFO Speed, Lag, etc. This versatile modulation capability places real-time control over many parameters of a voice's sound literally at your fingertips. VOICE ARCHITECTURE The high performance capabilities of the Matrix-12 are made possible by the use of computers to replace large amounts of electronic circuitry. This results in more reliable operation, and makes the Matrix Modulation'" system possible.

MODULATION CAPABILITIES: The Matrix-12's Matrix Modulation™ system is what sets it apart from conventional synthesizers. There are 27 modulation sources within every voice. Each of these modulation sources can be sent to any of the 47 modulation destinations on every voice. A source can go to many destinations at the same time, with independent control of each destination, positive or negative. FRONT PANEL Like the Xpander, the Matrix-12 incorporates 120 characters of flourescent alphanumeric display to show information about a Patch and its parameters. The Matrix-12 divides patch editing controls into sections called Pages, with all of the controls for that section available at once in the Page Modifier section of the front panel. For example, selecting the VCO 1 page causes all the controls and values for VCO 1 to appear on the front panel. The knobs and buttons can then be used to adjust the settings for VCO 1. When a new page is selected, the settings for VCO 1 are remembered, and the new page can be edited as desired.

Synthony Music On-Line

"The intention with the Matrix-12 was to offer, in a mid-1980's context, an instrument that had the routing flexibilty of the giant modular systems of the mid-1970's, wherein almost every parameter could interact using patch cords. The Matrix-12's "patch cords," of course, are hidden in software.

"It's an impressive-looking instrument, large to the point of bulkiness, with an exceptionally deep main panel awash with buttons and LEDs, like some sort of space- age board game. But it's not the system that's so radical on the Matrix-12 -- after all, it's fairly standard subtractive synthesis -- so much as the options offered.

"Beknobbed to an extent, the Matrix-12 is navigated with a page system of parameter access and soft buttons. Such a method may now be commonplace, but in 1985, it was new and not a little confusing.

"The instrument has 12 fully independent analog voices. Within a few years, what would become known as multitimbralism was also commonplace. Back in 1985, many of us nodded sagely at the prospect of being able to control individual voices on dedicated MIDI channels, but few thought many people would ever want to bother. In truth, the Matrix's system does not have the multitimbral flexibility of an 01/W, but for independent bass, pad and obligato parts, say, it is still more than sufficient.

"There's nothing too frightening about the VCO/VCF/VCA voice architecture. More daunting is the level of choice within each section. Each oscillator can be independently pitched, fine-tuned and set in volume. Page 2 of the oscillator controls provides access to waveforms -- triangle, sawtooth or variable pulse -- as well as the lag processor for portamento effects, pitch bend and vibrato. VCO2 also offers noise as an additional waveform.

"The oscillator pages are reasonably fathomable, but once you get into the filter pages, where a choice of some 15 filter modes and the myriad modulation routings (with no less than five envelope generators per voice, five LFOs and a ramp generator) confront you, then you'll need your wits about you. Oberheim breezily informs you that some 27 modulation sources can be sent out to some 47 modulation destinations.

"Filtering is a Matrix-12 specialty, with spectacular choices of one-, two-, three- or four- pole lowpass; one-, two- or three-pole highpass; two- or four-pole bandpass; band reject; phase shift; and several combined filter types. Add in tricks like being able to modulate filter resonance from keyboard dynamics, one of the LFOs, etc., and you can see that this is never going to be a quick or easy instrument to work with, in spite ot the plethora of Help pages and a clearly written and organized owner's manual.

"Does it sound any good once you have mastered it? Yes, it definitely does. The Matrix- 12 is a rich, multifaceted instrument, capable of enormous complexity and fine detail, perfectly suited for progressive noodlings a la Alan Holdsworth, who has loyally used the Matirx-12 and Xpander as a sound source for his Synthaxe guitar. This application as a sound source for a guitar controller makes perfect use of the Matrix-12's multitimbral capability for individual string bending sounds, etc. Texture hounds like The Orb also seem to have taken the Matrix-12 into the hearts.

"This is a synth with a thousand tricks up its software. It wasn't made in huge numbers, but since it is not for the fainthearted, most people on the lookout for a Matrix-12 should be rewarded in time.

Analog Synth Gallery

...that legendary colossus of a machine, the Matrix 12... Now the one thing that got everybody ga-ga about the Matrix 12 and Xpander (apart from the stupendous price tag) was the introduction of Matrix modulation. Contrary to popular belief the concept of Matrix modulation actually first appeared back in 1982 on an ARP designed instrument - the Chroma (manufactured by Rhodes) - but with the Matrix 12 and Xpander being covered in knobs and displays, Matrix modulation really came into its own.

Steve Huthwaite
Future Music: Issue 91 (Apr 2000)

The Oberheim Matrix 12 is quite possibly the best analog synthesizer ever built - with thorough MIDI specifications and a soundscape much deeper than you'd ever think of in an analogue instrument.


Oberheim Matrix 12, possibly the best analog synthesizer ever built - with heavy MIDI specifications and a sound you can die ( ....or even kill (sic).... ) for.

Synthesizer Timeline

A little-known fact these days is that you can experiment with FM-style programming if you own an Oberheim analogue synth of the right vintage. Both the seminal Xpander and the herculean Matrix 12 offer FM-style oscillator cross-modulation, and have the added flexibility of being able to use waveforms other than simple sines as both carrier and modulator. So, although the Oberheim version of FM is, strictly speaking, only 2-operator (ie. the two oscillators), you can arrive at very complex sounds like bells and tuned percussion very quickly, because of the additional harmonic content in the 'operator' waveforms which produce a very complex harmonic spectrum when cross-modulated. If you are looking to mix and match synthesis types, you could do far worse than acquire one of these vintage analogue synths (designed by Marcus Ryle and Michel Dodoic, now of Alesis fame). They sound excellent and are incredibly versatile -- and the Matrix 12 is also one of the few analogue synths to be truly multitimbral.

Paul Wiffen
Sound On Sound

The Oberheim Matrix 12 was a 12 voice analog synthesizer. This is, in my opinion, the "pad" machine. It is capable of creating the best sounding pads from long drawn out stringy sounds to the fattest and buzziest tones.


A true beast I'd love to tame.

Jetboy Junction

awesome for EWI players

The EWI Homepage

On a more historical note, an Oberheim Matrix 12 would be like manna from Heaven.

Simon Trask
Sound On Sound (Dec 1997)

Audio Review (Click for listening) from an unknown magazine

Analogue synth's must have been dead boring, back in 1985, compared to the new digital synth's, like the 'DX7'... At least, that's the impression you get, when you hear the stupid patronizing tone of the reviewer in this demo!

It's got some Matrix-12 music, followed by some sounds. Nuff said!

It should be understood that this track was copied from a music cassette which came on the front of a music magazine, some fifteen years ago!
As to be expected, the sound quality isn't quite what we have come to expect these days... I bought my first 'CD' player back in 1986, but CD's were not in general use (In the UK, at least) until a few years after that.
I have been able to remove most of the (considerable) background noise from the track, using special software. Unfortunately, it seems impossible to remove the hiss without also taking away some of the desired signal... I have done my best to try and make-up for those lost bits, using frequency boost filters.
I am afraid that there is no easy way for me to fix the drop-outs on this track. Hopefully, I will be able to fix those drop-outs in the future...

This track has been encoded at a slightly higher rate (160bit-HQ) than the standard Internet MP3 (128bit-??). Although this adds about 1MB to the file size, it makes a noticeable difference to the sound quality.


Mad Jack
Old Tape Demos

Links to reviews on Oberheim Xpander which can also be applied to Matrix-12:

Sound On Sound (Jan 1998)

Vintage Synth Explorer

Harmony Central

Other magazine reviews not online yet:

Keyboard: Jul 1985 (p88)

Keys: June 1993