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

Oberheim OB-MX

 

 

 

 

oberheim ObmX

info Country: USA
Weight: n/a
Dimensions: n/a
audio demo trend price : 600€
demo video comments

 

Oberheim OB-MX (1994)

Analog rackmount module synthesizer projected by Donald Buchla and not by Tom Oberheim as anyone would expect. The Obmx module has been a total commercial flop on the market with a lot of lawsuit stories and legends.

No support has ever been made for this machine soon forgot by the marketing machine.

oscillator pannel
oscillator pannel

info RACKMOUNT 5 units. Main panel features a 40 x 2 lines display, 32 knobs and 47 buttons.

Back panel terminal connectors:
- double main outputs
- individual out for each voice fitted (up to 12)
- MIDI interface
- separate outs can be used also as insert using a TRS cord.

Front panel terminal connectors:
- headphones.



 

edit VOICE subtractive synthesis machine features 2 voices polyphony for each voice card fitted up to a maximum of 12 voices.
A single voice is composed by 2 VCO oscillators based on CEM 3374 +1 white noise circuit. The voice can be tuned with MICROTONAL system according to 10 preset tables.




structure


oscailltor OSCILLATOR the VCO 1/2 are quite similar - check out sumup table:

  VCO1 VCO2
Level mix yes yes
Waveforms saw / tri / pulse saw / tri / pulse
Variable width yes yes
Tuning coarse and fine coarse and fine
Hardsynch VOC1> VCO2 VOC2> VCO1
Ringmodulator VCO1>VCO2 -
Pan image yes yes



filter FILTER multimode resonant VCF offers 2 models:
- VCF MM (stands for "Moog Minimoog"): lowpass at 4 poles slopes
- VCF OB (stands for "Oberheim SEM") with 2 poles highpass, lowpass and bandpass.
The signal routed to VCO can be balanced between VCO1/ VCO2/ noise, in addition a Keytrack function changes the cutoff scaling factor cutoff following 3 fixed proportional values: 1/3 - 2/3 - 3/3.


lfo


adsr ENVELOPE 4 EGs based on CEM-3381 (also 9 X SSM-2024 / board):
- EG1 VCF MM: 4 segments + 1 time
- EG2 VCF OB: 4 segments + 1 time
- EG3 auxilliary assignable: 4 segments + 1 time
- EG4 VCA: 4 segments + 1 time

Some extra special EG modes:
- freerun: finishes the segment even if no more triggered (for percussions)
- reset: a retriggered note goes ON with the previous EG value without restarting
- repeat: repeats the EG if not retriggered when a note finishes
- VCA offset: a drone mode.

EG


lfo LFO
up to 3 delayed modulators (shapes: saw, saw reverse, triangle, random and sample & hold) with variable symmetries:
- LFO1 VCF OB (also matrix assignable)
- LFO2 VCF MM (also matrix assignable)
- LFO3 freely assignable on the matrix like VCA / PWM / VCO.
Only FREE RUN LFO mode and no possible modulation retrig.

LFo


performance PERFORMANCE the digital VOICE ALLOCATION ALGORITHM assigns the availabe voices depending on number of installed boards, here's some of the playmodes:
- unison: stacks all available voices
- rotate: each new note is cycled on a voices from 1 to 12 (or less of courses)
- portamento with variable times
- stack:different patches layered in odd or even multiples modes
- split-stack: same as stack with split point
- chorus: a kind of detune to fat up sound.
The lower row voice status indicates the voice number being playing, pretty nice when using the special rotate mode creating a special analog feeling since all boards cannot sound precisely the same.



voice allocation


adsr MATRIX affects a parameter of a function with the output of another like a modular:


SOURCES: DESTINATIONS:
note VCO / MM+OB VCF /EG times
velocity EG levels
EG1-2-3-4 VCO / VCF MM
LFO1-2-3 VCF OB / VCO PWM
mod weel VCA
bender VCO / VCF MM
Midi CC# VCF MM / VCO PWM
Foot pedal VCO2
random VCO1

 


memory
MIDI knobs do not transmit any recordable CC#, but full sysex implementation.
Sadly no computer editor has been official made nor librarian.

 

 

memory MEMORY :
- 128 RAM patches
- 128 ROM patches
- 128 RAM performances
- 128 ROM performances
BATTERY REPLACEMENT model CR lithium 3V 2032 in battery holder replacement is quite easy.

 

battery replacement

 

memory MAINTENANCE UPGRADE todayvoice boards are quite impossible to find on the market, better buy a model already expanded. It *SEEMS* that OBMX voice boards have been reverse-engineered by third-part but project is now officially dead because unprofitable.

 

 

effet VST PLUGIN / SAMPLED VERSION free and commercial OBMX samples set:

  name price link demo
Sonic projects OP-X Sonic projects OP-X VST plugin.
There is no official OBMX plugin. However this plugin emulates the typical Oberheim sound
video
OBXD OBXD Same as above, but a free plugin video


demoAUDIO DEMO

demo factory demo
demo factory demo 2
demo factory demo 3
demo actory demo 4
demo factory demo 5
demo factory demo 6
demo factory demo 7
demo  




video YOUTUBE VIDEO CLIP SELECTION

Oberheim OB MX Oberheim OB-Mx Oberheim Oberheim OB.Mx + TR 626
demo1 demo2 with TR 626

 

OB LFO

My ex-OBMX (now sold) with other machines on rackmount:

Oberheim matrix 1000

Roland Mks-70

Waldorf Microwave

Roland D-550

Korg Wavestation AD

 

obehreim obmx





manual
Oberheim OBMX USER MANUAL

 

 




manual

OBMX SERVICE MANUAL

 

 

memory

OS latest and more stable Operating System is the 2.0 on EPROM that should be the most stable and less plagged by software bugs.

 

 

 




manual

EPROM OS DUMPS

 

 

 

original scan

 

 


OB-MX PROTOTYPE LEGEND

obmx prototype

Tt seems that some prototype units had a different design and a better sound. gossip? legend? who knows?

 

 

 

original scan

 

 

 

 

 

 

Oberheim OBMX
for sale

yamaha rx7 for sale
CHECK OUT EBAY OFFERS

 

 

 

 

 

obmx vs sem
OBMX behind


manual

- knobs... a lot!
-matrix control
-rare unit

manual

-sound
- filters

- limited Midi
- no support

-voice cards are rare

comment

REVIEW "OBMX is NOT what I expected: being a SEM and Minimoog fan I thought It could be the best things in the synth world in a big rack units... a big personal disappointment. "

 


oberheim logo
Remember the days when men were men and synthesizers were synthesizers? Knobs, switches, and such stuff we re in abundance, imagination could run rampant..." (Oberheim/Gibson)  

COMMENTS

 

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

all snapshots*, sounds, texts copyright Polynominal.com / Eric Pochesci
* prototype pic found on the net

Oberheim OBMX 2 out of 5 based on 44 ratings. price €600