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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.

Arturia AstroLab MIDI implementation

The MIDI implementation of the Arturia AstroLab: what it answers to, and the 37 controls it offers, on firmware 2.0.0.

At a glance

Firmware
This page describes firmware 2.0.0.
MIDI channel
Any one of 1 to 16.
Parts
Part, 2 of them: each on a MIDI channel of its own, taking notes and controls.
Voices
Not recorded.
Note range
Not recorded.
Velocity
Not recorded.
Aftertouch
Not recorded.
Pitch bend
Not recorded.
Program change
Received and sent.
MIDI clock
Received.
Start and stop
Received.
Control change
37 controls, in the tables below.
NRPN
Not recorded.
System exclusive
Not recorded.

Controls

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

Controllers

Control CC Values
Mod Wheel
mod_wheel		 1 0-127

Master

Control CC Values
Master Volume
master_volume		 7 0-127
Neither sent nor received

Pedals

Control CC Values
Expression
expression		 11 0-127
Aux 1
aux_1		 12 0-127
Aux 2
aux_2		 13 0-127
Sustain
sustain		 64 0-127

Effects

Control CC Values
Reverb
reverb		 16 0-127
FX B
fx_b		 18 0-127
Delay
delay		 19 0-127
FX A
fx_a		 93 0-127

Macros

Control CC Values
Timbre
timbre		 71 0-127
Brightness
brightness		 74 0-127
Time
time		 76 0-127
Movement
movement		 77 0-127

Faders

Control CC Values
Fader 4
fader_4		 72 0-127
Received, never sent
Fader 1
fader_1		 73 0-127
Received, never sent
Fader 2
fader_2		 75 0-127
Received, never sent
Fader 3
fader_3		 79 0-127
Received, never sent
Fader 5
fader_5		 80 0-127
Received, never sent
Fader 6
fader_6		 81 0-127
Received, never sent
Fader 7
fader_7		 82 0-127
Received, never sent
Fader 8
fader_8		 83 0-127
Received, never sent
Fader 9
fader_9		 85 0-127
Received, never sent

Functions

Control CC Values
Previous Preset
previous_preset		 102 0-127
Received, never sent
Next Preset
next_preset		 103 0-127
Received, never sent
Previous Song
previous_song		 104 0-127
Received, never sent
Next Song
next_song		 105 0-127
Received, never sent
Arp On/Off
arp_on_off		 106 0-127
Received, never sent
Arp Hold
arp_hold		 107 0-127
Received, never sent
Start Record
start_record		 108 0-127
Received, never sent
Play / Stop
play_stop		 109 0-127
Received, never sent
Tap Tempo
tap_tempo		 110 0-127
Received, never sent
Rotary Fast On/Off
rotary_fast_on_off		 111 0-127
Received, never sent
FX A On/Off
fx_a_on_off		 112 0-127
Received, never sent
FX B On/Off
fx_b_on_off		 113 0-127
Received, never sent
Delay On/Off
delay_on_off		 114 0-127
Received, never sent
Reverb On/Off
reverb_on_off		 115 0-127
Received, never sent

Where these facts come from

Source documents

How they were read

User Manual AstroLab, 145 pages, the edition Arturia's resources page calls 2.0.0 - "AstroLab 61 EN Manual Version en - 2.0.0" (resources_page), dated 2026-10-06. Arturia publishes no MIDI implementation document for this instrument, so the manual's own "11.3. AstroLab MIDI Implementation" (manual pp. 105-106) is the whole published control map: 37 rows under "Section Parameter MIDI CC Sending Receiving" (manual p. 105), with controller numbers from 1 to 115. The 1.5.1 edition prints the same table, cell for cell (manual_1_5_1 pp. 96-97), and is kept as a second source for that and because it is still the 88's newest English manual.

THIS DEFINITION IS THE ASTROLAB 61'S AND THE ASTROLAB 88'S, AND THE MAKER'S OWN DATA SAYS SO. Arturia sells three AstroLabs and the resources page carries a manual for each, but the 88's 1.5.0 and 1.5.1 entries both point at the 61's own file, under products/astrolab-61/; it has no 1.5.x document of its own, and the 2.0.0 edition is listed for the 61 alone. The manual agrees from the inside: its specification table is headed "AstroLab 61 AstroLab 88" (manual p. 105) and names the two keybeds separately - "AstroLab 61 : 61-note semi-weighted keyboard with piano-size keys and aftertouch" (manual p. 11) and "AstroLab 88: TP-40L hammer-action keybed with piano-size keys and aftertouch" (manual p. 11), the maker's own spacing. The release notes agree from the third side: the 88's list begins "First release of AstroLab 88" (release_notes_88) at V 1.5.0, the firmware the 61 was already running, and carries no MIDI change the 61's does not.

THE ASTROLAB 37 IS NOT IN THIS DEFINITION; IT IS arturia/astrolab_37. It has a manual of its own, at 2.0.0 as well; the words "AstroLab 37" appear nowhere in these 145 pages; and its release notes start at a version neither of the others has - "First release of AstroLab 37" (release_notes_37) at V 1.5.9 - and carry an entry theirs do not, "Reworked the ranges of some presets for better playability on AstroLab 37" (release_notes_37). Its own manual's table is this one less its two looper rows, Start Record and Play / Stop, a difference that definition records.

THE SECTION COLUMN IS A TRAP AND IS NOT USED FOR THE GROUPS. Six rows carry a label - MIDI, Master, Pedals, Instrument, Effects, Functions - and thirty-one leave that cell blank. The rows are in controller-number order, so sections cannot be contiguous, and carrying a label downward files Expression, Aux 1 and Aux 2 under "Master" and Timbre, Fader 4 and Fader 1 under "Pedals". Both are contradicted by the manual's own body. The second reading confirmed the shape rather than the meaning: six labels and thirty-one blanks, each in a cell of its own with a rule between every pair of rows and the zebra stripe running through, read off an eight-times render of the 1.5.1 edition. So the blanks are blanks and not merged cells, and the groups below are the body's.

THE FOUR DIRECTION WORDS. Always and Never are plain. n/a appears only against the nine Faders and marks a control with nothing on this panel to send it. Not linked is settled by the MIDI Out Filter: "Auto When AstroLab and Analog Lab are Linked, the MIDI Out Filter switches to Keyboard Only" (manual p. 28), where "Keyboard only Only the notes played on the AstroLab keyboard are transmitted via MIDI Out" (manual p. 28). So a Not linked row is sent whenever the instrument is not mirroring its software, and those seven are both. The counts: 13 both, 23 receives, and one row that is neither.

"MASTER VOLUME 7 NEVER NEVER" (manual p. 105) IS THE ROW THAT IS NEITHER, and the only one in the table whose Receiving cell is not Always. It is below with direction: none, in a group of its own under the table's own Master label: the knob that "Sets the volume of AstroLab’s main outputs" (manual p. 15), whose number the maker publishes and then says travels in no direction.

FOUR CONTROLLER NUMBERS ARE STATED TWICE, WHICH IS WORTH HAVING. The Macro knobs' row values - Timbre 71, Brightness 74, Time 76, Movement 77 - are given again in prose and in a different order: "The MIDI Continuous Controller (CC) messages sent by the Macro knobs are, left to right: 74, 71, 76, and 77" (manual p. 41), against "The four Macro knobs are Brightness, Timbre, Time, and Movement" (manual p. 41). The two agree, and they are what settles that Timbre is a Macro rather than the pedal the Section column would make of it.

NINE ROWS NAME SOMETHING THE MANUAL NEVER EXPLAINS. Fader 1 to Fader 9 take CC 72, 73, 75, 79, 80, 81, 82, 83 and 85, each n/a sending and Always receiving. Outside the table the capitalised word "Fader" appears only as four display names on one Sound Edit page, the CZ's Macro 1 to Macro 4 shown as Fader 1 to Fader 4 (manual p. 123), which are a software instrument's and not these nine, and the lowercase word only for the three-faders symbol that opens Sound Edit (manual pp. 36 and 43). Their numbering does not follow their controller numbers either - Fader 4 is 72 and Fader 1 is 73 - and 78 and 84 are skipped between them. They are below as published, ungrouped with anything else, and what they are is left unrecorded.

TWO PARTS, EACH ON A CHANNEL OF ITS OWN. "Part 1 Input Channel After clicking the Navigation Wheel, you can set the MIDI receive channel by rotating the wheel" (manual p. 27) and "Part 2 Input Channel Same as above, but for Part 2" (manual p. 27), with "The two Parts in AstroLab can conveniently listen to separate channels" (manual p. 27) and "Selecting All makes AstroLab listen to all MIDI channels" (manual p. 27). What a Part answers to is given from the other side: "There are also switches that let you decide if Part 1 will be affected by Pitch Bend, Mod Wheel, Aftertouch, Sustain and Expression Pedal or not" (manual p. 36).

THE MANUAL CONTRADICTS ITSELF ABOUT THE TRANSMIT CHANNEL, SO NEITHER STATEMENT IS RECORDED. Page 27 says "The Main MIDI Channel is the channel used by the AstroLab keyboard to send data, and it is fixed and cannot be changed" (manual p. 27). Page 28 says "Keyboard Channel Here you can set the MIDI Output channel of the AstroLab" (manual p. 28), describing "what MIDI channel your keyboard transmits notes and data on" (manual p. 28). Page 36 sides with the second: "Part 1: Here you can set the Low Note and High Note limits, MIDI input and output channels, and Octave and Semitone Transpose" (manual p. 36). Two statements against one, and nothing here turns on it - channels below records the receive range, which all three agree on.

POLYPHONY IS A PROPERTY OF THE LOADED ENGINE AND NO SINGLE NUMBER EXISTS. The manual publishes a table of maximum voices per instrument running from 1 to 48 across some forty engines, under "AstroLab manages polyphony to ensure that you will never hear audio dropouts" (manual p. 38), the same table as the 1.5.1 edition's, though the 2.0.0 notes list "Synthx polyphony and performances" (release_notes) among their improvements. No figure is recorded, because the format holds one number and this instrument has forty. What is recorded is that the two Parts do not share: "These are voices per part, meaning that if you load, for example, a Multi consisting of a Mini V and Prophet-5 V, you can play 16 voices on each part" (manual p. 39).

CLOCK AND TRANSPORT COME IN AND DO NOT GO OUT. "Internal: AstroLab uses its own master clock" (manual p. 69), "USB: AstroLab syncs to incoming MIDI clock over USB" (manual p. 69) and "MIDI: AstroLab syncs to incoming MIDI clock over the 5-pin MIDI input" (manual p. 69), with a precedence rule - "If multiple clocks are detected, AstroLab chooses USB above 5-pin MIDI" (manual p. 69) - and transport in the same list: "If a MIDI stop message or clock interruption is detected, the MIDI looper (if playing) pauses" (manual p. 69) and "If a MIDI start message is detected, playback resumes synced to the external clock" (manual p. 69). No setting anywhere sends either, and the MIDI Out Filter's widest position is "All Notes Played notes, arpeggiated/sequenced notes, chords, and scale quantized notes (processed MIDI) are transmitted" (manual p. 28), which is notes and nothing else.

PROGRAM CHANGE IS IN THE RELEASE NOTES AND NOWHERE ELSE. The word "program" appears once in the manual's 145 pages and not in that sense; the implementation table has no row for it. Both directions come from the firmware history: "AstroLab can now send Program change to External devices" (release_notes) under V 1.5.0, and "Program change no longer reacts to all MIDI channels" (release_notes) under V 1.3.5. No preset count is recorded: the manual says "Over 1,800 built-in sounds across all types of synths and keyboards" (manual p. 11), and "over" is not a number of addressable locations.

NOT RECORDED, EACH FOR A STATED REASON. No mode, because Arturia publishes no implementation chart and no document names a mode. No system exclusive and no NRPN, because neither term appears in any document held here - the table is controller changes only, and it leaves 0 and 32 alone along with 96 to 101. No note range, because this definition covers two instruments with different keybeds and the manual gives neither as a span of note numbers. No pitch_bend: a Part may be switched to answer to pitch bend or not (manual p. 36), which is neither a range nor a setting of one, and no document says how far it reaches. And nothing from the CheatSheet, which carries no controller number, no channel and no MIDI setting at all.