This page is read from MIDI Instrument Definitions, a Python library used in the author's other projects, in which every number is traced to a document its maker published. Its source is on GitHub.

Korg opsix MIDI implementation

The MIDI implementation of the Korg opsix: what it answers to, and the 30 controls it offers, on firmware 3.1.0.

At a glance

Firmware: This page describes firmware 3.1.0.
MIDI channel: Any one of 1 to 16.
MIDI mode: 3: omni off, poly.
Voices: 32.
Note range: 0 to 127: C-1 to G9, counting middle C as C4.
Velocity: Sent and received. Release velocity is received.
Aftertouch: Channel pressure and polyphonic, each answered. It sends none.
Pitch bend: Not recorded.
Program change: Received and sent, with 500 presets.
MIDI clock: Sent and received.
Start and stop: Sent and received.
Control change: 30 controls, in the tables below, 1 of them with a fine half on a second controller number.
NRPN: Not recorded.
System exclusive: Supported.

Controls

In the order the definition gives them, by group. Under each control is the name a program calls it by, once pymidiinstrumentdefs.load("korg/opsix") has loaded them.

Voice assign

Control	CC	Values
Glide Time `voice_assign_glide_time`	5	0-127
Glide Mode `voice_assign_glide_mode`	65	0-127

Home and algorithm

Control	CC	Values
Algorithm `home_algorithm_algorithm`	70	0-127
Attack `home_algorithm_attack`	73	0-127
Decay/Release `home_algorithm_decay_release`	79	0-127
FX1 `home_algorithm_fx1`	81	0-127
FX2 `home_algorithm_fx2`	82	0-127
FX3 `home_algorithm_fx3`	83	0-127

Filter

Control	CC	Values
Resonance `filter_resonance`	71	0-127
Cutoff `filter_cutoff`	74	0-127

Operators

Control	CC	Values
OP1 Level `op1_level`	102	0-127
OP2 Level `op2_level`	103	0-127
OP3 Level `op3_level`	104	0-127
OP4 Level `op4_level`	105	0-127
OP5 Level `op5_level`	106	0-127
OP6 Level `op6_level`	107	0-127
OP1 Ratio `op1_ratio`	108	0-127
OP2 Ratio `op2_ratio`	109	0-127
OP3 Ratio `op3_ratio`	110	0-127
OP4 Ratio `op4_ratio`	111	0-127
OP5 Ratio `op5_ratio`	112	0-127
OP6 Ratio `op6_ratio`	113	0-127

Without a group

Control	CC	Values
Bank Select `bank_select`	0 fine 32	0-127
Modulation `modulation`	1	0-127
Volume `volume`	7	0-127 Received, never sent
Pan `pan`	10	0-127 Received, never sent
Expression `expression`	11	0-127 Received, never sent
Damper `damper`	64	0-127
Sostenuto `sostenuto`	66	0-127 Received, never sent
Soft `soft`	67	0-127 Received, never sent

Where these facts come from

Source documents

opsix/opsix SE/opsix module Owner's Manual, E 6, dated October 2023, its user manual, read on 2 October 2026 (the file read).
opsix MIDI Implementation Chart, decoded, Version 3.1.0, dated 17 January 2023, its MIDI implementation, read on 2 October 2026 (the file read).
opsix Property Exchange MIDI Implementation, Version 1.0, dated 9 September 2025, its MIDI implementation, read on 2 October 2026 (the file read).
Downloads | opsix mk II | KORG (USA), its download page, read on 2 October 2026 (the file read).

How they were read

Owner's Manual, the edition Korg names E 6, 117 pages, published 10/2023: printed pages 105 and 78, the MIDI settings on p. 41, and the chart on p. 116 through a decoded rendering of it, for the reason given against that source.

THE MIDI IMPLEMENTATION CHART IS THE WHOLE OF THE PUBLISHED MAP, and it is a chart rather than a table of parameters: it gives 23 control change entries, each with a number or a run of numbers, a mark for what the instrument transmits, a mark for what it recognises, and a remark naming what the number reaches - "Algorithm" in the Home/Algorithm page, "Resonance" parameter in the Filter page, OP1-6 Level sliders, and so on. There is no second table anywhere in the manual, searched for and absent.

THREE OF THOSE 23 ENTRIES ARE NOT CONTROLS AND ARE NOT BELOW. Two give a span rather than a controller - 1 to 119 "Assignable for Virtual Patch sources" (chart), which the instrument recognises and does not send, and 1 to 119 "Transmittable from Motion Sequencer" (chart), which it sends and does not recognise. So any controller in that span may be made to do something, and which one is the player's business. The third is 120 and 121, the channel mode pair, which is a fact about MIDI rather than about this instrument.

THE CHART'S TWO COLUMNS DISAGREE ON FIVE OF THE THIRTY CONTROLS, which is what direction exists for: volume, pan, expression, sostenuto and soft are recognised and never sent, and are marked receives below. The other twenty-five travel both ways.

AFTERTOUCH IS RECEIVED IN BOTH ITS FORMS AND SENT IN NEITHER, on this model. The chart marks both Key's and Channel aftertouch as recognised, marks Channel as transmitted and Key's as not, and footnotes both "Only the opsix SE can send aftertouch" (chart) - and the specifications agree, giving the opsix 37 keys without aftertouch where the SE has 61 with it. Which form reaches the sound is then a setting: "Aftertouch Src ... Ch: Channel pressure is applied ... Poly: Polyphonic key pressure is applied. The effect intensity varies according to the note number" (p. 78), and a fourth setting takes both at once - "Both: Both channel and polyphonic key pressure are applied" (p. 78). So voice.aftertouch is both, since this instrument answers to either kind and which one reaches the sound is the player's setting, and aftertouch_transmits is false.

THE PROGRAM CHANGE REACHES A HUNDRED OF FIVE HUNDRED. The chart gives program change as 0 to 99 in both directions, and the instrument holds "500 programs (350 preset programs and 150 user programs as the factory-set default)" (p. 6). Bank select is the other half of that, MSB and LSB, which the chart gives as controller 0 and 32 and the manual never mentions. Five banks of a hundred is the arithmetic and not the maker's word, so presets records the hundred the chart states.

NOT RECORDED: the pitch bend range, which the chart marks as travelling both ways and never quantifies, and which no page of the manual states in semitones.