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Korg M1R



korg m1r rack expander
audio demo trend price : 150€
manual schematic.zip factory patch demo video comments

KORG M1r (1988)


Rack version of the best-seller workstation M1 with exactly same sonic characteristics.

Today, is the M1r still worth to be in a modern recording studio?

korg m1

music workstation

info RACK 2 units, same steel frame structure found on 01RW.
The main panel has a 16 * 40 LCD display and features 36 buttons + a main data pot encoder for value editing, double slots for PCM and data cards and a headphones outputs.
Back panel terminal connectors: Midi interface, main outputs plus another AUX pair (stereo or mono + mono) and double pedal inputs freely assignable to program change up-down, sequencer start-stop, effect ON-OFF, filter cutoff, data entry or effect parameter controls.

ac Power supply is internal.

edit VOICES the NEC-V50 CPU manages 16 digital oscillators based on 16 bit AI System subtractive synthesis.
A basic patch is composed by 1 Single mode or 2 Double Mode detunable digital oscillators OSC1+ OSC2 with variable Octave range and Coarse. An oscillator has a PCM waveform assigned from the wavetable and this waveform can be read at variable memory offset and start-delayed.
waves WAVETABLE has 4 Mb data ROM for a total of 149 different waveforms split in 2 main sounds groups:
- Acoustic sampled traditional instruments strings, violins, sax, piano + 50 PCM percussions and one-shot drums.
- DWGS originally developed with model DW8000 synthesizer: mathematically generated PCM pre-calculated waves such as additive harmonic, Vocal Formants, plus digital basic derived from standard analogs synthesizers Sine, Saw or Pulses.

waves UPGRADE standard M1R model has 4 Mb ROM expanded to EX that means +4 Mb more, for a total of 8 Mb. Even more waveforms can be added using external Korg M1/T1 PCM cards, compatible with other 16 bits AI system like Wavestation but loop corrections are needed for some minor bytes differences in coding.
EX upgrade is factory native in successive T series.

performance PERFORMANCE called COMBI mode manages up to 8 patches in the same time with individual Midi channels, Volume mix, Transpose, Detune, Zone Split, Velocity Split and Damper on filter.

filter FILTER section is the VDF (Variable Digital Filter( is a digital non-resonant LowPass Filter with Keytrack function.

adsr ENVELOPE there are 6 EG in total:
- AMPLITUDE VDA for OSC1 and OSC2 4 segments + 2 times.
- FILTER VDF for OSC1 and OSC2 4 segments + 4 times.
- PITCH EG for OSC1 and OSC2 4 segments + 2 times.

lfo LFO section features two modulators MG: MG1 modulates OSC1-OSC2 Pitch while MG2 modulates VDF.
Each LFO has 4 waveforms (Triangle, SawUp, SawDown and Square) with variable Depth intensity and Key-Sync retrig function with Delay Start parameter.


fx EFFECT two DSP sound processor at 16 bits resolution that can be combined in parallel or serial mode 9 FX categories (reverb, delay, overdrive, EQ, chorus, rotary speaker, phase shifter, frequency exciter and flanger).
Some typical metallic feedbacks in audio background.

memroy MIDI limited Control Changes implementation but the exclusive systems are complete.
The function MINDSCOPE is a neat too for incoming events monitoring.

edit SEQUENCER up to 8 tracks sequencer up to 10 songs + 100 patterns 4400 notes (7700 reducing memory balancing between patch / combi). The sequencer works in real-time or step notes mode (quantizing up to 1/48 resolution).

memroyMEMORY internal holds up to 100 patches + 100 Combi in RAM, but NO ROM recall. Internal voice backup on lithium Cr-2032 or backup to a RAM card mode MCR03 must be a 256 Kb memory as it is not compatible with 128 Kb MCR-02. Internal battery is cheap and easy to change.

scales SCALES one Microtonal user-free slot + 4 presets: Equal Temp 1-2 + pure Major-Minor.

korg m1 battery
battery CR2032 internal

repariMAINTENANCE original round buttons on M1 keyboard version are fragile and it is not uncommon to see some not working anymore, rackmount is really more reliable for this.

family Related M1R models:

related family

KORG M1: 61 keys keyboard version
KORG T1 (EX) (88-note weighted piano keyboard)
KORG T2 (EX) (76-note keyboard)
KORG T3 (EX) (61-note keyboard)

cards audio demo AUDIO DEMO


m1r ATARI Notator with Korg M1R KORG M1R EX
M1r demo ATARI Notator with Korg M1R KORG M1R EX



original scan


original scan



buy m1 memorry cards




isnide M1r main board Korg m1r close up


- Classic
- bread'n butter
- today bargain price


- limited filter
- some PCM
- fx unit



"Compact version of the M1 legend! today some sounds may be a bit outdated, but still an interesting programmable machine with character and dynamics in the mix. "


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

korg m1r 4 out of 5 based on 33 ratings. price €150