Oberheim Xpander + Oberheim Matrix 12

Oberheim Xpander + Oberheim Matrix 12
analogue synthesizer – made in 1984 (xpander) 1985 (matrix 12)
DAS Analogschl8schiff! THEEE Analogue Megasynth!! built/Bj.: 1984
this is the multilingual version..

oberheim xpander analog synthesizer
Oberheim Xpander – Oberheim Matrix-12
Oberheim Matrix12 oberheim matrix 12 and oberheim xpander analog synthesizer


Oberheim Oberheim Synth overview..
General InfoOberheim Xpander
+ Matrix 12

2 VCOs, VCOs syncable,
5 LFOs,
5 ENVs,
3 Tracking Generators,
4 Ramp-Generators (mini envelopes),

and yes, it is an expander, t
the matrix 12 is the “keyboard version” but with 12 voices. a double version!

LPF,HPF (1-4 Pol), BPF (2 & 4 Pol), Notch, Phase (3 Pol), and Combinations: HPF (2-3 Pol)+LPF(1 Pol), Notch (2 Pol) + LPF (1 Pol), Phase (3 Pol) + LPF (1 Pol) , Filter FM and Oszillator FM modable
6 CV + Gate input Jacks / cv/gate-Anschlüsse, not on Matrix 12

Footswitch for switching the Patches + 2 defineable – Fußschalter um Soundprogramme umzuschalten und 2 frei definierbare,

Kassettenrecorder rein&raus (für sounds, jaja.. veraltet aber gibts.. geht auch über MIDI Dump) / Tape Recorder interface for saving the patches (really, that time this was the usual, remember the good ol’ commodore C64??)

Einzelausgänge für jede der 6 Stimmen und zusätzlich: links, recht und Extra-Monoausgang!
Individual outs for every of the 6 voices, dedicated Mono Master out AND left&right main out!!
MIDI in , out, thru (no comment)

Memory Protect Schalter/switch, Triggereingang/trigger input,’

100 soundspeicherplätze/patches, 100 Multis, Unisono mode (doubles the sound up to 6 voices) und 3fache Zonenverwaltung (3 Zones for Keyboard range, Transpose, Pan, CV, Volume und/and extra Vibrato LFO (global).. ja der ist zusätzlich!!/yes its n.other additional LFO!!! go for it!!

LFO max Frequency: ca. 25 Hz,triggerable(triggerbar)/triggermode einstellbar/triggermode adjustable multi/single/external), Tri,Saw up/down, Square, Random, Noise, Sample(&Hold) von allen Modulationsquellen (all mod sources!!)!!

VCOs: Tri,Saw,Pulse,Noise (Noise nur (only) VCO2) alle einzeln schaltbar (all seperately switchable,mixes signals!), Pulsbreite einstell- und modulierbar(Modable Pw/PWM: Pulsewidth), LAG (for delaying signals & portamento) prozessor für Signal-Verzögerungen und Portamento
MOD / Controller – INFO
Alles modulierbar von: alle obigen Quellen,
you can mod every target by these mod sources
Keyboard, Vel, Wheel/Lever/Pitch, Controller, Pressure, Rel.Velocity, Pedal1/2, Vib-LFO, LAG.(everything’s modable by those & the above sources!!)

Oberheim Xpander – the mod source keys..
Modwheel => Lever!! the wheels are called levers

globally for all sounds in a multi –
und gilt global für alle Sounds in einem Multi.

Modulation can not be done via controllers exept those 5 self definable controlles that can be assigned… like pedal 1, pedal 2, levers 1-3, ..
warning: Modwheel works for all sounds in a multi!!, for indy mod use other controllers eg: pedals 1,2 (you can set Controllers for them!!).. etc..
Modulation geht nicht über Controller aber über Pedal 1,2, Pitchwheel (auch ein “Lever”)… alle Mod-Quellen Quantisierbar (Stufen erzeugen) the wheel&Pitchbend are called levers!!..

oberheim xpander analog synthesizer
enlarge Oberheim Xpander – click the image above!

oberheim xpander
xpanderbild 3
o b e r h e i m xpander back side
n.other xpander
oberheim xpander structure
oberheim xpander structure
oberheim x p a n d e r

n.other xpander

The Difference
Matrix 12 vs. Xpander
the Matrix 12 has a Modmatrix-Page.. so this is why its name is Matrix12 and not Xpander 12 or so.. the xpander has CV/gate.. the Matrix12 does not! it can convert CV to midi using these inputs!! the Xpander has 6 indie outs for every of the 6 voices.. also right, left AND mono out!!! (you can pan in multi!) the Martrix12 can be DIY’ed to 12 outs.. but of course does not have 12 indy outs! some got it.. some don’t. so it was optional! the M12’s Keyboard is a Velocity and Release Velocity KB.. the Aftertouch was optional too!! (try it!!). in multi mode the Matrix12 has a detune parameter.. the Xpander only provides Octave settings in halftones.. so this M12 only detune mode is responsible for very fat (phat!?) sounds.. but don’t worry: the Xpanders fatness at simply stacking them at the same pitch is fat n.off!!!
btw: the matrix 12 has 6 “zones”, the xpander has 3… a zone has key limits, midi channel and some settings like key assign mode (rotate, unison, reassign etc..)
Oberheim Matrix12
enlarge Oberheim Matrix12 – click the image above!
Xpander Movies

to see it opened/offen (Movie/Film)

xpander opened movie
Movie: to see it opened
click here (Quicktime movie)
!!!.. (1.3MB)
THE OBERHEIM Xpander .. and Matrix-12
more Xpander Pictures

more Xpander interior images.. Xpander von innen..

EXTERNAL / normal view / back side
– more Xpander images.. (exterior) – Xpander von aussen

oberheim matrix 12 and oberheim xpander analog synthesizer
enlarge Oberheim Matrix12 + Xpander – click the image above!
about modulation: modulations on the Xpander is very easy but note that the Modwheel (or whatever you call it..) always affect every voice in multimode! what to do? you cannot change the midi channel for modwheel / it makes no sense .. so use pedal oder pitchbender or other controllers for modulation on a specific sound.. I recommend the other levers , pedal (I always route it to a CC and use a CC box to control it!!)
DO THIS: (press this: master page – midi – ctrls )
Same path/key: (midi – enables) systemx and control should be enabled!!..
and: All parameters can be controlled by sysex! it’s not fast but it works..
oberheim xpander modulation
Xpander / M12 Tricks
Tricks and tips
x-pander / matrix 12:
if you need more headroom: simply stack up those modulations.. means: add another one and it is twice as strong..
in case of running low on LFOs (haha.. 5 arent n.uff, huh??) use the VIB LFO!!!
want some cool waveforms on LFOs??
apply the tracking generator, also usefull for any controilled as a scaling tool. it also make a simple “microtuning” feature when applied to the VCO pitch it is another scale then well tempered ;-) (if you don’t like Bachs inventions).. of course you can do that also using a KBD mod on the VCOs at some amount and switch of the hardwired KB-mod in VCO’s page 2!

the VCOs are still to high or too low
make it more phat: use a fast ramp on the pitch (try all: both, or only one VCO or different ramps at little difference modding those VCOs

want a real sample and hold?? use the LAG using exp., RATE=63.Modulate the rate with the “GATE”: GATE=63 => sample, GATE=0 =>hold
for your mega sound?? use a ramp at no ramp time and add the desired tuning.. so you can get another osctave lower

and of course the gate is another way of transposing if you do not want to sacrifice ramps.. but note that it flips back when in “release” state!! (maybe a nice effect.. sometimes unwanted..
the speed of ramps may be better for drums/percussion (faster)
I have never owned a manual.. but if you want a fast number without having to turn up the knob encoders simply enter any number above the maximum soo… 88 or 99 is good for making it +63 .. and 666 ;-) (!!!) or 999 (or any other number exept 111 will give you the max setting faster than turning the knob!!.. works fine for me.. ;-)

thats all!! for now!!! ;-)


oberheim xpander

Das WICHTIGSTE: das Ding klingt EXZELLENT!!!

now the important one: it sounds WHAAAAAAAAAAAAAAA!!!!

Review in german / deutscher Test Zum Xpander Test / Review
oberheim xpander pictures synthesizer
check the autotune function (select une page then press ALL)…
Wait a moment and all need to say “PASSED”, (no “FAIL”!!)

Also check all 6 voices, you can see the voice card activities by a dot. So set it to rotate mode and press a key 6 times. You should hear the same sound EXACTLY 6times. And all sound the same, no volume or filter changes.

If that is ok, I assume the machine works fine.
also check the 6 endless encoders: if they jump it is possible to clean it, I did it, it works..
find some patches under download/patches (synthesizer menu) you can also listen to some sounds as mp3.

in germany the price is about 2900-3000.-DM (Xpander).. add about 1500.- to get a Matrix 12
der Preis in Deutschland liegt zzt bei ca. 3000.- // ein MAtrix 12 liegt bei 4500.- (etwa!)..

nochmehr Oberheim Xpander
searching for a Matrix12??? do not get a late model.. the ppl at Oberheim (later Gibson, now Viscount – so the OB12 is no way an oberheim and.. well its sound is far from Oberheim sound!!!) where more “tolerant” and built in some “out of tolerance” parts.. so.. and: the M12’s are sometimes getting more hot because the double number of voices had to be in.. (see the video of the Xpander! lots’a’ space in it!!).. so this is my tip.. and try all voices by playing all or set it to rotate mode and check all voices by ear.. those chips aren’t sooo easy to get these days.. what chips are used?? look here
6 3372 Signal Processor
6 3374 Dual VCO
2x 6809 processors
Curtis 3320 VCF or equivalent
filters made with an extra ciruitry in the servical manual a one percent resistor array. this chip provides LPF 4pole filter only!
2 processors running at 16mhz.
there is also the noise gen on the processor board!
the first is responsible for the display and encoders, the other is for env and lfo generation..
dual vco cem3374
filters made with an extra ciruitry in the servical manual a one percent resistor array. this chip provides LPF 4pole filter only!
2 processors running at 16mhz.
there is also the noise gen on the processor board!
the first is responsible for the display and encoders, the other is for env and lfo generation..
inside an



hardware: inside the Xpander the processor upper board: its a 6809.this is the lower board..
the processor is the one on the right (big).. and yes: its two 6809’s
oberheim xpander processor board
processor board 2 oberheim xpander
this is 2 voices using curtis 3320 equivalent chips
(the one used in the MW1,too..)
xpander voice board oberheim xpander
want the little quicktime-movie??

Matrix 12 inside
oberheim matrix 12 inside
oberheim matrix 12 inside

software versions /
Softwareversionen/most recent software version:
Processor: 1.2 (Matrix12: 1.1)
Voice version: 1.4 (Matrix12: 1.6)
Cassette is always 1.0 for both (eehm.. do you use it!?)
check it?? / wie geht das?? press Master, then 2nd Page, choose “versions”… thats it!

btw: earlier (like the one shown here) are made in usa! later models are made in japan. so prefer the usa-made versions
another nice cool xpander inside page: here main entrance to that site is here

oberheim xpander
how does it sound?

Xpander -Audiodemo..


some more of my patches:
x_ymod.mp3 – fm like..
Patches / Sounds..? special sounds and audio..
see the patches area!!
(click patches!)
FORUM – for tech questions and more here! –
für technische fragen und mehr.. im FORUM fragen!
Manuals Manuals and Infos /
Bedienungsanleitungen? / Service-Info:
got service manual here incl. CEM chip ;)
will upload it as soon as I can reduce 35MB to something around 2MB..
das service manual zum xpander habe ich hier.
Manuals? / Bedienungsanleitungen? / Service-Info:

werkssounds? bei den patches!! / the factory preset sounds? are unter “patches”.. or download them here: as ZIP as SIT (mac stuffit).

some demos?? most of my songs are done using the Xpander.. and: some demo audio files in the patches section / in der patches sektion gibt es audio demos zum xpander!

PATCHES are available in the download/audio area.. also some mp3’s!! SOUNDS für den Xpander gibts unter Download/Audio!!

software emulation xpander? matrix12? not yet. the rights are still at gibson – they do not say yes!
so don’t wait for it
Developers on the Matrix12 / Xpander Marcus Ryle, Michael Doidic (who is now at Line6),
Anna Graham, Jim Letts, Ale Silverman

read those names in the secret “hey mom (xpander)”
or “hey dad” (matrix12) secret page

External in

the oddernmart mod..

i am still searching for Xpander re-engineers! there is a lot of sonic potential in the xpander and matrix series! so if you know someone? let me know! imo the most interesting things are:
-faster lfos and envs
-audio ins (this is possible,there are some manuals around here in the net! but some use the noise sourse INSTEAD!)
-the resonance is so awsome, but steps 60-63 especially 62 t o63 is too large, so a higher resolution would be a good solution – of course this would kill any compatibelity to other xpanders..
the LFO speed is imo the 1st priority. but for this one may need to replace the complete control system. it’s all old technology.. ;)
it replaces the noise to get the signal in and put it through the xpander filters. oddernmart mod from chris bouchers site

Matrix 12: Ind. outs retrofitted by Oberheim themselves.. looks like this


back / zurück
the Oberheim Menu
more info and links to other pages xpander and matrix 12 some xpander / matrix 12 links:


here is a another collection of sound dumps and link and facts listed..:

and here is a nice SOS article

Oberheim Oberheim Synth overview..

oberheim matrix 12 and oberheim xpander analog synthesizer
Oberheim Matrix12
oberheim matrix 12 and oberheim xpander analog synthesizer
oberheim x-pander info -end-
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Mehr analoges im Moogulatorium.. / more Analogue? see the Moogulatorium..

Oberheim Oberheim Synth overview..