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 volca bass MIDI implementation

The MIDI implementation of the Korg volca bass: what it answers to, and the 12 controls it offers.

At a glance

Firmware: Not recorded.
MIDI channel: Any one of 1 to 16.
MIDI mode: 3: omni off, poly.
Voices: Not recorded.
Note range: 0 to 127: C-1 to G9, counting middle C as C4.
Velocity: Received. Release velocity is ignored.
Aftertouch: None, sent or answered.
Pitch bend: Not recorded.
Program change: Not received or sent.
MIDI clock: Received.
Start and stop: Received.
Control change: 12 controls, in the tables below.
NRPN: None.
System exclusive: None.

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/volca_bass") has loaded them.

Oscillators

Control	CC	Values
OCTAVE `octave`	40	0-21 `oct_1`, 22-43 `oct_2`, 44-65 `oct_3`, 66-87 `oct_4`, 88-109 `oct_5`, 110-127 `oct_6` Received, never sent
VCO PITCH 1 `vco_pitch_1`	43	0-127 Received, never sent
VCO PITCH 2 `vco_pitch_2`	44	0-127 Received, never sent
VCO PITCH 3 `vco_pitch_3`	45	0-127 Received, never sent

LFO

Control	CC	Values
LFO RATE `lfo_rate`	41	0-127 Received, never sent
LFO INT `lfo_int`	42	0-127 Received, never sent

Envelope

Control	CC	Values
EG ATTACK `eg_attack`	46	0-127 Received, never sent
EG DECAY/RELEASE `eg_decay_release`	47	0-127 Received, never sent
CUTOFF EG INT `cutoff_eg_int`	48	0-127 Received, never sent

Performance

Control	CC	Values
SLIDE TIME `slide_time`	5	0-127 Received, never sent
EXPRESSION `expression`	11	0-127 Received, never sent
GATE TIME `gate_time`	49	0-127 Received, never sent

Where these facts come from

Source documents

KORG volca bass MIDI Implementation, Revision 0.01, dated 23 June 2013, its MIDI implementation, read on 5 October 2026 (the file read).
volca bass MIDI Implementation chart, E 1, dated 10 June 2013, its MIDI implementation, read on 5 October 2026 (the file read).
volca bass Owner's Manual, EFGSCJ 4, dated 7 November 2024, its user manual, read on 5 October 2026 (the file read).
Downloads | volca bass | KORG (USA), its download page, read on 5 October 2026 (the file read).

How they were read

The volca bass MIDI Implementation, "Revision 0.01 (2013.06.23)" (implementation), a 3.4 KB plain text file rather than a PDF; the volca bass MIDI Implementation Chart, whose single sheet is cited throughout as p. 1, carrying Ver.: 1.01 and dated 2013. 06. 10 on its face; and the volca bass Owner's Manual, edition EFGSCJ 4. All three are offered on one Korg downloads page, which is saved beside them.

THE IMPLEMENTATION IS THE SOURCE OF EVERY NUMBER and the chart is a second reading of it. Twelve control changes, and both documents name all twelve - checked one by one rather than taken on trust, because the chart's names live in its Remarks column, which is text, where its answers do not.

THE CHART'S ANSWERS ARE DRAWINGS. 59 marks inside the table, a circle for yes and a cross for no, and nothing in the text layer to say which is where. They are read by what each path is made of - curves against straight lines - which is sound here because the chart uses no other shape inside its rules. Thirty crosses in the Transmitted column and not one circle, nineteen circles in the recognised one. The legend below the table prints one of each beside the words it defines, and is excluded by the table's own bottom rule rather than by eye.

WHAT THE TWO DOCUMENTS DISAGREE ABOUT is one footnote on pitch bend; see the comment above the definition. What they agree about is everything else, including the direction of every message, the twelve numbers, and their names bar one spelling: the implementation prints EG DECAT/RELEASE where the chart prints EG DECAY/RELEASE, and the chart is the one that can be read as a word. The implementation also prints Contiune for Continue in its realtime table. Two typos in 3.4 KB, both carried here as findings rather than as names - the control below takes the chart's spelling.

AND ONE SMALL DEFECT IN THE IMPLEMENTATION'S OWN APPARATUS: its channel-message table defines [H]:Hex, [D]:Decimal and its system-common table then heads two columns Second[B] and Third[B], where [B] is defined nowhere. From the bit patterns printed under it, it means binary.

THE ONE THING ONLY THE IMPLEMENTATION SAYS is what a Song Position Pointer does here: "pppp : 0~15 = STEP 1 ~ STEP 16" (implementation), with the rest of the message's bits marked ignored. So this instrument reads a song position as a step within one sixteen-step pattern and discards the bars - which is a sixteen-step sequencer's honest reading of a message meant for a longer song, and the chart says only that the message is received.

THE THREE DOCUMENTS ARE DATED THREE WAYS AND NONE OF THEM AGREES WITH THE PAGE THAT OFFERS THEM. The chart's face says 2013. 06. 10, its own metadata says it was made on 2013-06-14, and the downloads page dates the file 2015.06.01. The implementation's face says 2013.06.23 and the page dates it 2016.01.08. Neither date on a page is a date in a document, which is worth knowing before citing either: the dates recorded in the sources below are the documents' own.

Korg encrypts every PDF it serves for this instrument with an empty password, as it does for the volca drum - noted because a reader whose tool refuses them is meeting a setting and not a fault.