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.

Novation Circuit Tracks MIDI implementation

The MIDI implementation of the Novation Circuit Tracks: what it answers to, and the 358 controls it offers.

At a glance

Firmware

Not recorded.

MIDI channel

Any one of 1 to 16.

Parts

Synth, 2 of them: each on a MIDI channel of its own, taking notes, controls, and program changes, with 6 voices each.
Drums: on a MIDI channel of its own, taking notes and controls.
MIDI track, 2 of them: each on a MIDI channel of its own.
Project: on MIDI channel 16, taking controls and program changes.

Voices

Each part's own, under Parts.

Note range

Not recorded.

Velocity

Not recorded.

Aftertouch

Not recorded.

Pitch bend

Not recorded.

Program change

Received and sent, with 128 presets.

MIDI clock

Sent and received.

Start and stop

Sent and received.

Control change

114 controls, in the tables below.

NRPN

Supported. 244 of the controls below have one.

System exclusive

Supported.

Controls

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

Synth

Voice

Oscillator

Mixer

Filter

Envelope

LFO

Effects and EQ

Mod matrix

Macro knobs

On the base MIDI channel

Audio

Drums

Drum control

Project

Reverb

Delay

Master filter

Sidechain

Project mixer

Additional controls

MIDI track

MIDI template

Where these facts come from

Source documents

• Circuit Tracks Programmer's Reference Guide V3 - EN, Version 3, dated 19 October 2022, reference, read on 3 October 2026 (the file read).
• Circuit Tracks User Guide V3 English, Version 3, dated 25 August 2022, its user manual, read on 3 October 2026 (the file read).
• Circuit Tracks | Novation Downloads, its download page, read on 3 October 2026 (the file read).

How they were read

Circuit Tracks Programmer's Reference Guide V3 - EN, 22 pages, created 2022-10-19 by its own metadata, and the Circuit Tracks User Guide V3 English, 109 pages, created 2022-08-25. Both come off one downloads page, which is saved here as well. The reference guide is the control map; the user guide carries the channels, the tracks, the polyphony, the patch count and one control table the reference guide does not have.

THE CONTROL MAP IS SEVEN COLUMNS AND IS ONE OF THE BETTER ONES IN THIS CORPUS: Section, Parameter, CC / NRPN, Control No., Range, Default Value and Notes, over pp. 3-8 for a synth track and p. 12 for the project. So every row carries its own range and its own factory default, and 62 of them carry their states as well. 314 rows come off those pages, 28 more off the drum table on p. 11, eight off the Audio Table on p. 9 and eight out of the user guide, which is 358 controls - and makes this the largest definition here.

THE SECTIONS ARE DRAWN AS FULL-WIDTH BANNER ROWS and are the groups below, so nothing had to be inferred from a sparse label column. Two of them are both called Mixer, which is why one of them is project_mixer here: the synth's holds six oscillator and effect levels, and the project's holds the two synth levels and pans.

THE PROJECT TABLE'S PARAMETER NAMES ARE RELATIVE TO THEIR SECTION, so each takes its section as a name prefix while the synth's keep theirs as printed. Nine would otherwise collide - two rows called type, two called frequency, two called resonance, and six send levels printed once under Reverb and again under Delay. The labels are left exactly as printed, including the maker's own inconsistent capitals: lfo 1 one shot beside Lfo 1 common sync, and mod matrix 12 Source 2 beside eleven lower-case ones.

AN NRPN IS PRINTED AS MSB:LSB AND IS RECORDED AS MSB x 128 + LSB, the number that goes on the wire, and this guide proves that reading twice over from the inside. The modulation matrix is twelve slots of four parameters at five-number intervals - slot 1 at 1:83 and slot 12 at 2:10 - and in the combined number those are 211 and 266, which is 55 apart, or eleven steps of five across the MSB boundary exactly where the arithmetic puts it. And the macro knobs occupy 3:0 to 3:127 with nothing left over: eight knobs of sixteen parameters is 128 numbers, which is one full MSB page.

EACH MATRIX SLOT IS FIVE NUMBERS AND ONLY FOUR ARE PUBLISHED. Slot 1 gives source 1 at 1:83, source 2 at 1:84, depth at 1:86 and destination at 1:87, and 1:85 is named nowhere; the same gap sits in all twelve slots, so twelve numbers in that block do something the guide does not say.

RANGES ARE PRINTED TWICE OVER WHERE A CONTROL IS SIGNED - 0 - 127 (-64 - 63) with a default of 64 (0) - and the first of each pair is the wire value. That is what range and default hold; the bracketed half is what the instrument's own display shows and is not something to send. Two rows print a unit instead of a second range, -12 to +18 dB (guide p. 3) against a wire range of 52 to 82, and two more give a span in degrees for a wire range of 0 to 119.

FOUR VALUE TABLES ARE PRINTED ON pp. 9-10 AND TWO OF THEM HOLD TWO LISTS UNDER ONE HEADING, both restarting at 0. The Filter Table gives "Drive Type" 0 to 6 and then "Type" 0 to 5; the Mod Matrix Table gives "Source" and then "Destination". Reading either as one list produces a value map with the same number in it twice, so each row takes the sub-list its own name and range point at: drive type over 0-6 takes Drive Type, a matrix source row over 0-12 takes Source, and a destination row over 0-17 takes Destination.

THE AUDIO TABLE'S CHANNEL HAS THREE CANDIDATES AND NO STATEMENT, which is why those eight controls carry no part. Its own numbers rule out the channels the rest of the document uses: CC 13 is Keyboard Octave and 31, 33, 35 and 36 are oscillator 2 parameters on a synth channel, and CC 15 is drum 1 decay on channel 10. What is left is the project's channel 16, which the interleaving of 12, 13, 14 and 15 argues for, or the MIDI tracks' 3 and 4, which the user guide argues for instead: "on the MIDI tracks, these act on the analogue audio signal applied at the two audio Inputs" (user_guide p. 57), those tracks defaulting to channels 3 and 4 (guide p. 15). Two readings of the document arrived at those two answers independently, which is the clearest evidence that it does not say.

THE REFERENCE GUIDE HAS A PAGE ITS CONTENTS DOES NOT LIST, and it is the page that states the channel defaults: p. 15, "Setup View", which gives "Default MIDI channel for Synth 1 is Channel 1" (guide p. 15), the same for Synth 2 on 2 and "Drums 1-4 is Channel 10" (guide p. 15), and "MIDI 1 and MIDI 2 are set to use their default MIDI channels - 3 and 4 respectively" (guide p. 15). It also labels the channel pads "MIDI channels 1 -16" (guide p. 15) while saying on the same page that "MIDI Channel 16 is reserved for the Project" (guide p. 15), which is the one place the two documents together leave it unclear whether a track may be put on 16 at all. Nothing here rests on that; channels records the span.

FOUR RANGES BELOW SELECT FROM LISTS THAT ARE PRINTED NOWHERE, which is this guide's largest hole. Every macro knob n destination runs 0 to 70 and no table names any of those 71 destinations - 32 controls. Every sync division runs 0 to 35 and no table names the 36: both LFOs' delay sync and rate sync, the chorus rate sync and the project delay's time sync. Each drum n patch select runs 0 to 63 and no document names a sample. And the eight switches packed into NRPN 0:122 leave values 0 to 11 and 20 to 21 unaccounted for, where the Synth Patch Format shows the same byte is a bit field - "LFO1_OneShot (bit 0), LFO1_KeySync (bit 1)" (guide p. 17) and so on.

THE PATCH FORMAT REACHES FURTHER THAN THE CONTROL MAP IN ONE PLACE. It names modulation matrix slots 1 to 20 where the control map stops at 12, so slots 13 to 20 exist inside a patch and no control change or NRPN reaches them. Nothing here is recorded for them: a byte in a file is not something a consumer can send.

THE MOD MATRIX'S SOURCE LIST IS NOT CONTIGUOUS, which is why it is choices and not values. It names ten sources against a stated range of 0 to 12 - direct at 0, then velocity at 4 and on up to env 3 at 12 - and 1, 2 and 3 are named nowhere in either document. A reader who assumed the list filled its range would mis-address seven of the ten.

ONE ATTACHMENT IS AN INFERENCE AND IS THE ONLY ONE HERE. The filter's type, CC 68 over 0 to 5, carries no pointer at all, where its neighbour drive type says "See Filter Table" (guide p. 3). The Filter Table's second list is headed "Type" and has exactly six entries over 0 to 5, so that list is recorded against it. Nothing says so in words; it rests on the heading, the range and the name agreeing.

THE DRUM TRACKS ARE FOUR THINGS ON ONE CHANNEL, which is the one place this instrument's shape does not fit a part each. "Messages on MIDI Channel 10" (guide p. 11) heads a table of 28 controls, seven for each of four drums, and the user guide confirms that "all four drum tracks use the same MIDI channel" (user_guide p. 103). So the four are one addressable part here, and which drum a note sounds is the Drum Notes Table on p. 11: 60, 62, 64 and 65.

128 PATCHES AGAINST A PUBLISHED PROGRAM CHANGE RANGE OF 0 TO 63, and both numbers are stated plainly. "Each of the two synth tracks can use any one of 128 pre-loaded Patches" (user_guide p. 33), arranged as four pages of 32, while the reference guide's Patch and Project Select table gives program change 0 - 63 for synth 1 on channel 1 and the same for synth 2 on channel 2 (guide p. 10). Nothing in either document says how the other 64 are reached, or whether a bank select exists. presets records what the instrument holds and this paragraph records the half the published range can address.

ONE NUMBER IS ALMOST CERTAINLY A MISPRINT AND IS RECORDED AS PRINTED. The sidechain's synth 2 depth is given as NRPN 1:69 where every other sidechain parameter is in the 2:xx block: synth 1's five run 2:55 to 2:59, and synth 2's run 2:65, 2:66, 2:67, 2:68 and then 1:69. Nothing in either document settles it, so the printed number is what is here, with the doubt written beside the control. 1:69 is 197 where 2:69 would be 325, so a consumer that reaches for the one the pattern implies would be addressing something else entirely.

THE GUIDE'S FIRST SENTENCE ABOUT THE SYNTHS IS MISTYPED, and it is worth knowing because it is the sentence that assigns the channels: "Send messages on MIDI Channel 1 for Synth 1 and Channel 2 for Synth" (guide p. 3), and then a full stop. The missing 2 is a typo rather than an ambiguity - the user guide's own table gives Synth 1 on channel 1 and Synth 2 on channel 2 (user_guide p. 103). The full stop is left outside the quotation because it does not survive both PDF readers used here: this guide's text layer loses two of them and the whole of its contents page's leader dots to one reader and not the other, which is 2,172 characters.

NOT RECORDED, EACH FOR A REASON. Aftertouch, because the word appears nowhere in either document - 131 pages between them and not one mention. Pitch bend, because the only place it appears is as two engine parameters, osc 1 pitchbend and osc 2 pitchbend, each setting how far that oscillator bends; the one page that lists what messages the instrument answers to names "MIDI Note On/Note Off, Program Change (PGM) and Continuous Controller (CC)" (user_guide p. 107) and does not name pitch bend, so recording a bend range would claim a response nothing states. The note range of the synth tracks, which no page gives: the grid is "a set of 32 illuminated, velocity-sensitive pads" (user_guide p. 5) whose notes depend on the scale and root note chosen, and nothing says what an incoming note number outside that selection does. And the MIDI mode, there being no implementation chart in either document.

THE ENGLISH USER GUIDE IS THE ONLY ONE AT V3. The downloads page offers the user guide in 27 languages, and the other 26 are "Version 2"; there is one Programmer's Reference Guide and it is English only. So a reader working from a translation is working from an earlier edition of the document this definition cites, and no translation was compared against it.