polynominal logo
Synthesizers Drum machines Samplers Effects 8-16bits+ toys HOME

Oberheim DMX





oberheim dmx

info Country: USA
Weight: 5,5 Kg
Dimensions: 45,7 X 30 X 12,7 cm
audio demo trend price : 700€
manual demo video comments

Oberheim DMX
Programmable Digital Drum Machine (1981)


Classic American drum machine based on primitive 8-bits samples but great sound: this is the history of eighties music from New Order to Run DMC.

dmx logo

info DRUM MACHINE The main panel features a flurescent display, 10 sliders for volumes mixing, 24 buttons for edit and 18 trigger pads with no velocity.

Back panel terminal connectors:
- 12 separate mono jack outs
- 2 pedalswitch inputs for start-stop and NEXT pattern
- sync tape interface
- external clock I/O
- switch tab for memory protection
- tape interface
- custom 3 x 4 molex connectors: the 1st molex row is "TRIGGER IN" and each instruments can be controlled by a simple pulse (range +1-5V).


edit VOICE main CPU based on a Z80 Zilog manages 8 slot-in voice boards, and all boards have a trimmer for pitch tuning. Each voice board contain various 4 kb EPROM model 2732 with companded 8-bits digitalized sounds and some longer sounds (like crash) take a total of 16 kb split in 4 x 2732 EPROM. demo pitch tuning from trimmer LISTEN

zilog z80


edit BOARD EXPANSION it is also possible to use different sets of boards, many were available at that time or directly burn the EPROM memories with new samples.
TECH: some earlier DMX models have a tom board which lacks the famous CEM IC.

pitch eprom

edit PCM SOUND 24 sounds derived from the PCM EPROM combined in various pitches:
- bass drum: loud / medium / soft
- crash cymbal
- snares: loud / medium / soft
- tambourines: loud / soft
- hi-hats: close / accent / open
- toms: from high to low pitch
- shakers: loud / soft
- ride cymbals: loud / soft
- handclap
- rimshot.

pitch eprom

edit CV the second molex labeled "CV IN" changes samples pitches within a 0-6V range.
Some third-part sellers build some early Midi trigger system.

trigger cv gate

works in 2 main modes:
- real time with metronome (variable dividers) and correction-quantisation from 1/48 to 1/4 note.
- step by step: just entry pauses or notes between 1/4 value and 1/48.
Other functions for edit like COPY, OVERDUB, ERASE notes/ patterns/ songs/ instruments or variable time signature.
SYNC tempo can be set with internal clock from 25 to 250 BPM or slaved to SYNC TAPE or trigger input pulse at 96 PPQ (not so common).

demx record


is non-volatile:
- 2000 events
- 100 sequences
- 50 songs.
A special board doubled the internal memory clipped to the Z80.
The board usually "updates" to OS 3.1 which adds some new sequencer functions.

DMX memory board
(above) early DMX CEM LESS, upgraded to 3.0 OS with extra patterns memory board.


edit MAINTENANCE there are 2 common issues out of 2 models I owned:
- BATTERY: internal rechargeable battery just leaks on the circuits and damage the nearby ICs logics; often the first symptom is troubles with unstable clock frequency.
- DISPLAY :often some display modules fail and some gibberish characters appear - found some spare parts on Ebay at *EVIL* price.

battery replacement

dmx display module

battery leakage repair second module failure! (thanks to topopiccione)


obehreim DX
Faulty display module replacement (there are 4)



obehreim DX

DX - was the successive economic version of DMX with different sample and a single board for voice samples.
Some of the US versions were Midi factory upgraded.


edit VST PLUGIN / SAMPLED VERSION there are some free and commercial samples set:

  name price demo
dmx samples Dubsound free sample pack N/A



demo SuperMIX: OB DMX + Synthesizer Novation Bass station II
demo pattern demo1
demo rhythm pattern 2
demo pattern demo1
demo rhythm pattern 2


ovation Oberheim DMX + Yamaha TX81Z uper Bass Station DMX Old School Drum Machine DMX VINTAGE DRUM MACHINE
with Yamaha TX81Z Old School Drum Machine vintage drum machine


oberheim dmx drum machine

Company: Oberheim
Model: DMX
Class: Drum machine
Dates: 1981
Price: 700€
Synthesis: PCM
Polyphony: 8 channels
Sounds: 24
Sequencer: 2000 events
Sync: at 99 PPQ

Memory: 2000 events
Demo: 5





Power supply

DMX exists in both 110V and 220V version with VOLTAGE inversion internal switch -CHECK IT ANYWAY! - open the box and it is straight on the AC.



dmx banner


original scan
manual original Brochure


original scan
manual original Brochure


original scan
manual original Brochure


original scan
manual original Brochure


original scan
manual original Brochure


new order dmx
video Blue monday with Oberheim DMX



dmx banner

DMX voice cards for sale
DMX original Soundboards for sale!





oberheim logo mainboard DMX EPROMS DMX
Old school king


REVIEW "Not as popular as Linn drum, but Classy vintage drum machine with great sequencer. You might be interested also in cheaper SCI drumtraks"

manual manual
-Sequencer -Sync
- getting pricey

Add Comment or Review



polynominal logo
      For sale Comment Contact
Synthesizers Drum machines Samplers Effects 8-16bits+ toys HOME

all snapshots, sounds, texts copyright Polynominal.com / Eric Pochesci

Oberheim DMX 4.0 out of 5 based on 15 ratings. price €700