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Korg EX-800


Korg ex800

info Country: Japan
Weight: 2,5 Kg
Dimensions: n/a
audio demo trend price : 200€
manual factory sounds demo comments

Korg EX-800 (1984)
Programmable Polyphonic Synthe Module


Module of the famous polysynth Poly-800 with some handy technical enhancements.

korg ex800

info MODULE unit can be rackmounted with optional ears.
Main panel features basic alphanumeric display, 15 buttons and 3 knobs

Back panel terminal connectors:
- Midi interface (with Thru)
- tape inferface
- headphones
- main signal out
- pedalswitch input for program UP
- switch selector between synth and tape mode

ac Power supply is external with 9V with negative on center.



edit TECH main unit is a 8 bits controller CPU Intel 8050 family.
Music oscillator DCO is based on a OKI MS-M5232 chip, best known as implemented on some early '80 arcade games (now emulated by famous MAME emulator).

DCO Editing parameters The OKI generates 8 DCO digitally controlled oscillators assignable in 2 different manners:
- double mode: 2 x 4 voices for a thicker richer sound2
- whole mode: 1 x 8 voices for full polyphony.


DCO DCO an oscillator features 2 summable waveforms sawtooth and square + 4 additive harmonic octaves heights at 16' 8' 4' 2' + 1 white noice generator.

waveforms demo Hear OKI square wave

demo Hear OKI sawtooth wave

EDIT INTERFACE poor and sluggish with 1 parameter per time.

ex800 tech


there are 3 EGs with ADBSSR segments, wich stands for: Attack, Decay, Break point, Slope, Sustain and Release.

waveforms - 1 DCO1 amplitude: 6-stages ADBSSR
- 1 DCO2 amplitude: 6-stages ADBSSR
- 1 VCF: 6-stages ADBSSR

lfo LFO there are 2 delayed triangle-shapped modulators triggered by joystick control.

waveforms - MG LFO 1 modulates FILTER VCF
- MG LFO 2 2 modulates DCO pitch.

filter FILTER
a limited paraphonic filter based on a single NJM2069:


memroy TheNJM chip is a resonant (but not up to self-resonance) bipolar analog 4 poles lowpass with cutoff and contour.

- click to enlarge pic -



fx EFFECTS analog stereo chorus board based on BBD 3209 + driver 3102.
BBD 3209

edit SEQUENCER features a very basic 256 steps sequencer syncable to external Midi clock

BBD 3209

memroy MEMORY:

DCO Editing parameters

- 64 RAM patches (NO ROM memory recall)
Midi Sysex has been implemented from previous poly-800.

memroy Battery replacement: RAM system based on soldered CR2032 battery


memory OS latest official is unknown n 27c64 eprom

internal k1

DOWNLOAD BIN it for free update -


repair synthex MODIFICATION filter VCF values are quantized in 99 numbers but some nice guys made out a nice hardware modifications Moogslayer that adds 2 real-time knobs for cutoff filter and resonance.


memroy Moogslayer mod

demotest cutoff HEAR

warning EX-800 RELATED MODELS:


Poly-800 first version, It is quite the same it but features a Chorus board instead of digital delay. Memory backup system is older with no CR-2032 battery and no Sysex handling.

Poly-800 II enhanced POLY-800 with new motherboard and a 12 bits digital delay.

korg ex800 MEX-8000 memory expansion adds 4 extra banks.

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

EFM Oddse

- Poly-850 commerical VST then renamed X-POLY

- Bedroomproducers free sample set

poly 800 plugin



original scan 2 original scan 2
original scan 3

Company: Korg
Model: EX-800
Class: Synth module
Dates: 1984
Display: alphanumeric
Synthesis: analog
Oscillator: 1 / 2 DCO
Polyphony: 8 voices
Filter: low pass
LFO: 2 modulator
Envelope: 3 EGs
Sequencer: 256 steps
Sync: Midi Clock
Effect: analog chorus
Memory: 64 patches
CPU: 8050 Intel
Sound IC: MS-M5232



demo Machinery - all poly800 : overdub+drum + vocoder Roland SVC350
demo All poly800 + Volca beats drums
demo shine on your strings
demo moogish
demo Moogslayer bassline
demo ->more Demo at the POLY800 MK2 page

demohave some ex800



service manual

factory patch load


-More DEMO

edit Sample SHOP
edit Report Error


Korg EX-800 FOR SALE

Korg EX-800 for sale


tech poly800


DCO program Oki MSM5232 filter VCF


solid solid
Cheap as hell nervous edit


REVIEW "classic cheap poly analog - still affordabl. Don't expect too much sonic power: poly/ex800 is pretty raw and basic. "

manual manual
-cheap - edit
- analog
- storage
-new features -sequencer

"This instrument has been engineered for highest quality sounds and superb reliability" - Korg Manual


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* but pic number 3 from ebay auctions.

Korg EX-800 Korg EX-800
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