124 124 Canon

By James Saunders

Canon takes a melody on CV In 1 (with its gate or clock on Pulse In 1) and plays it back as a four-voice canon. Voice 1 is the input line itself; Voices 2, 3 and 4 follow it. Each delayed voice can be inverted (strict, or tonal within the notes the line uses) and shifted by octaves. Rests in a gate sequence are counted and passed on to every voice. The mode is chosen at power-on from the Main knob's six marks. Everything else is set with Z held down while stopped, and saved when Z is released. Each mode keeps its own settings. BEAT Voices enter a set number of steps behind Voice 1, locked to the incoming pulses. Rests are kept. FREE The same delay patterns, measured in time rather than steps. STEP All voices share Voice 1's rhythm; each plays the pitch from N notes earlier. TEMPO Tempo canon, each voice at one constant tempo. DIVERGE: all start together, V2-V4 slower (e.g. 4:5, 3:4, 2:3), drifting apart. CONVERGE: V2-V4 faster (5:4, 4:3, 3:2), entering one by one so that all meet Voice 1 after N steps, then stop. HETEROPHONY Every note is played by all four voices, each a little early or late within a time window that drifts smoothly from note to note.

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Panel

Controls

Main knob

Internal tempo
20-300 BPM, only when Pulse In 1 is unpatched. After Settings it waits until you move it.

X knob

Unused

Y knob

Unused

Switch

Play: With Pulse In 1 patched, the canon starts on the next pulse.

Stop: All outputs follow the input; LEDs show the input note name.

Settings (only while stopped): Hold and turn a knob = page 1 (the mode's own settings). Hold 1 s without touching a knob until the LEDs flash = page 2 (voice octaves and strict/tonal), then keep holding and turn knobs. Release Z to save. A knob does nothing until you turn it a little; the LEDs show the knob turned last.

Next inversion pattern: Quick press and release of Down (under 0.4 s, no knob moved). Order: none, V2, V3, V4, V2+V4, V3+V4, V2+V3, V2+V3+V4. The LEDs show the pattern for 1.5 s (LED 1 = marker, LEDs 2-4 = Voices 2-4 inverted). Hold 0.4-1 s and release to just view it.

Inputs & Outputs

Inputs

Outputs

Inputs

CV 1

Pitch In
V/oct melody to be canonised, quantised to semitones. Calibrate once: patch CV Out 1 -> CV In 1, hold Z Down and power on; an LED bar fills over ~4 s, all six LEDs = saved, LEDs 1+6 blinking = failed.

Pulse 1

Gate / Clock In
Gate (or clock) from the sequencer. Each pulse is a note; the card learns the step length and keeps counting steps through rests. Gates of 20 ms or longer also pass their rests on to the delayed voices. Unpatched, BEAT and STEP run from the internal tempo (Main).

Outputs

Audio 1

Voice 3
Built-in triangle synth voice

Audio 2

Voice 4
Built-in triangle synth voice

CV 1

Voice 1
Calibrated 1V/oct — the input line (never inverted)

CV 2

Voice 2
Calibrated 1V/oct

Pulse 1

Voice 1 Gate
High while Voice 1 sounds; drops 3 ms before each new note

Pulse 2

Voice 2 Gate
High while Voice 2 sounds

LEDs

LED 1

Voice 1
Flashes on each Voice 1 note

LED 2

Voice 2
Flashes on each Voice 2 note

LED 3

Voice 3
Flashes on each Voice 3 note

LED 4

Voice 4
Flashes on each Voice 4 note

LED 5

Input Pulse
Flashes on each pulse at Pulse In 1

LED 6

Clock Present
On while a clock is coming in

Controls

Main knob

Unused

X knob

Unused

Y knob

Unused

Switch

Play: With Pulse In 1 patched, the canon starts on the next pulse.

Stop: All outputs follow the input; LEDs show the input note name.

Inputs & Outputs

Inputs

Outputs

Inputs

CV 1

Pulse 1

Outputs

Audio 1

Voice 3
Built-in triangle synth voice

Audio 2

Voice 4
Built-in triangle synth voice

CV 1

Voice 1
Calibrated 1V/oct — the input line (never inverted)

CV 2

Voice 2
Calibrated 1V/oct

Pulse 1

Voice 1 Gate
High while Voice 1 sounds; drops 3 ms before each new note

Pulse 2

Voice 2 Gate
High while Voice 2 sounds

LEDs

LED 1

C / F#
Input note name — alone = C; all on except this one = F#

LED 2

C# / G
Alone = C#; all on except this one = G

LED 3

D / G#
Alone = D; all on except this one = G#

LED 4

D# / A
Alone = D#; all on except this one = A

LED 5

E / A#
Alone = E; all on except this one = A#

LED 6

F / B
Alone = F; all on except this one = B

Controls

Main knob

Step size / Unit / Converge (page 1) · Inversion type (page 2)
Page 1. BEAT: step size — LED 1 1/4 | LED 2 1/3 | LED 3 1/2 | LED 4 1 step (default) | LED 5 x2 | LED 6 x3 | not 1 x4. FREE: time of one unit — LED 1 100 ms | LED 2 150 | LED 3 200 | LED 4 250 | LED 5 300 | LED 6 400 | not 1 500 (default) | not 2 600 | not 3 750 | not 4 1 s | not 5 1.5 s | not 6 2 s. TEMPO: LED 1 DIVERGE (default) | LED 2 converge at 8 steps | LED 3 16 | LED 4 32 | LED 5 64 | LED 6 128 | not 1 256. STEP, HETERO: unused. Page 2: LED 1 strict (default; C D E -> C Bb Ab) | LED 2 t…

X knob

Delay / Ratio / Spread (page 1) · Voice octave (page 2)
Page 1. BEAT: delay pattern in steps. FREE: delay pattern in units. STEP: notes back. (Delay patterns in summary; default LED 2 = 2-4-6.) TEMPO: tempo ratios (in summary; default LED 4 = 4:5, 3:4, 2:3). HETERO: spread window — LED 1 0 ms (unison) | LED 2 50 | LED 3 100 | LED 4 200 | LED 5 300 | LED 6 500 (default) | not 1 750 | not 2 1 s | not 3 1.5 s | not 4 2 s | not 5 3 s | not 6 4 s. Page 2: octave of the voice chosen with Y — LED 1 -2 | LED 2 -1 | LED 3 0 (default) | LED 4 +1 | LED 5 +2.

Y knob

Octave of Voices 3+4 (page 1) · Voice to edit (page 2)
Page 1, all modes: LED 1 -3 | LED 2 -2 | LED 3 -1 | LED 4 0 (default) | LED 5 +1. Page 2: LED 1-4 = Voice 1-4.

Switch

Play: With Pulse In 1 patched, the canon starts on the next pulse.

Stop: All outputs follow the input; LEDs show the input note name.

Inputs & Outputs

Inputs

Outputs

Inputs

CV 1

Pulse 1

Outputs

Audio 1

Voice 3
Built-in triangle synth voice

Audio 2

Voice 4
Built-in triangle synth voice

CV 1

Voice 1
Calibrated 1V/oct — the input line (never inverted)

CV 2

Voice 2
Calibrated 1V/oct

Pulse 1

Voice 1 Gate
High while Voice 1 sounds; drops 3 ms before each new note

Pulse 2

Voice 2 Gate
High while Voice 2 sounds

LEDs

LED 1

Value step 1 / 7
Alone = setting step 1 ("LED 1"); off with all others on = step 7 ("not 1"). After a tap, LED 1 is the inversion-pattern marker. On page 2 with Y, LEDs 1-4 = Voice 1-4.

LED 2

Value step 2 / 8
Alone = setting step 2 ("LED 2"); off with all others on = step 8 ("not 2"). After a tap, lit = Voice 2 inverted.

LED 3

Value step 3 / 9
Alone = setting step 3 ("LED 3"); off with all others on = step 9 ("not 3"). After a tap, lit = Voice 3 inverted.

LED 4

Value step 4 / 10
Alone = setting step 4 ("LED 4"); off with all others on = step 10 ("not 4"). After a tap, lit = Voice 4 inverted.

LED 5

Value step 5 / 11
Alone = setting step 5 ("LED 5"); off with all others on = step 11 ("not 5").

LED 6

Value step 6 / 12
Alone = setting step 6 ("LED 6"); off with all others on = step 12 ("not 6"). All six flash when page 2 opens.

README

Play a melody into it from a sequencer and it comes back as a canon: delayed, tempo-scaled, inverted (strict or tonal) and octave-shifted copies of your line.

Pick the mode with Main at power-on. Everything else is set with Z held Down while stopped, and saved when you let go.

Basics

Patch: sequencer pitch → CV In 1, sequencer gate → Pulse In 1.

Output	Voice
CV Out 1 + Pulse Out 1	Voice 1 (the input line as direct output)
CV Out 2 + Pulse Out 2	Voice 2
Audio Out 1	Voice 3 (built-in synth)
Audio Out 2	Voice 4 (built-in synth)

Mode: set Main to a panel mark, then power on. 1 - BEAT · 2 - FREE 3 - STEP 4 - TEMPO 5/6 - HETEROPHONY.

At power-on the LEDs show the mode (LED 1–5), then the firmware version in binary (LED 1 = 1, LED 2 = 2, LED 3 = 4, LED 4 = 8, LED 5 = 16; v0.16 = LED 5 alone).

Z switch: Up = play · Middle = stop · Down = settings (only works while stopped).

Reading the LEDs in settings — every setting is a position on a 12-step scale:

Steps 1–6: one LED lit (LED 1 … LED 6).
Steps 7–12: all lit except one ("not 1" … "not 6").

LEDs while playing: LED 1–4 flash when Voice 1–4 plays a note; LED 5 flashes on each input pulse; LED 6 stays on while a clock is coming in. While stopped: all outputs follow the input and the LEDs show its note name (C = LED 1 … F = LED 6, F♯ = not 1 … B = not 6).

Changing settings

Stop first (Z Middle). There are only three things you do with Z:

Do this	Gets you
Hold Z Down and turn X, Main or Y (immediately)	Page 1 — the mode's own settings (below). Release Z = saved.
Tap Z Down quickly (no knob)	Cycles through inversion patterns (see In every mode).
Hold Z Down 1 second (no knob) until the LEDs flash, keep holding	Page 2 — voice octaves and strict/tonal. Release Z = saved.
The LEDs always show the knob you turned last. Each mode remembers its own settings.

1. BEAT

Voices 2–4 come in a set number of steps after Voice 1, locked to the input pulses. Rests are kept.

Knob (Z held)	Sets	LEDs
X	Delay pattern for V2-V3-V4	LED 2 = 2-4-6 steps (default). See Lookup tables.
Main	Step size	LED 1 ¼ · LED 2 ⅓ · LED 3 ½ · LED 4 = 1 step (default) · LED 5 ×2 · LED 6 ×3 · not 1 ×4
Y	Octave of Voices 3+4	LED 1 −3 · LED 2 −2 · LED 3 −1 · LED 4 = 0 · LED 5 +1

Example: X = LED 2, Main = LED 4 → V2 2 steps behind, V3 4, V4 6.

2. FREE

The same delay patterns as BEAT, but measured in time, not steps. The voices don't follow the beat grid.

Knob (Z held)	Sets	LEDs
X	Delay pattern for V2-V3-V4	LED 2 = 2-4-6 (default). See Lookup tables.
Main	Time of one unit	LED 1 100 ms · LED 2 150 · LED 3 200 · LED 4 250 · LED 5 300 · LED 6 400 · not 1 = 500 ms (default) · not 2 600 · not 3 750 · not 4 1 s · not 5 1.5 s · not 6 2 s
Y	Octave of Voices 3+4	LED 4 = 0 (as BEAT)

Example: X = LED 2, Main = not 1 → V2 1s behind, V3 2s, V4 3s.

3. STEP

All voices play together on Voice 1's rhythm. Each plays the pitch from a set number of notes earlier, producing cycxling chords derived from the melody.

Knob (Z held)	Sets	LEDs
X	How many notes back for V2-V3-V4	LED 2 = 2-4-6 notes (default). See Lookup tables.
Main	— (not used)
Y	Octave of Voices 3+4	LED 4 = 0 (as BEAT)

4. TEMPO CANON

A tempo canon: each voice plays the line at its own constant tempo causing the voices to converge or drift apart.

Knob (Z held)	Sets	LEDs
X	Tempo ratios for V2-V3-V4	LED 4 = 4:5, 3:4, 2:3 (default); LED 1 = gentlest. See Lookup tables.
Main	Diverge or converge	LED 1 = DIVERGE (default) · converge at: LED 2 64 steps · LED 3 96 · LED 4 128 · LED 5 192 · LED 6 256 · not 1 384 · not 2 512 · not 3 768 · not 4 1024 · not 5 1536 · not 6 2048
Y	Octave of Voices 3+4	LED 4 = 0 (as BEAT)

DIVERGE: all voices start together on the first note; V2–V4 are slower and drift further apart the longer it plays.
CONVERGE at N steps: V2–V4 are faster. They come in one by one, catch up and land on Voice 1's note at step N, hold it, then everything stops on the next note. Z Middle, then Up, to play it again.

5. HETEROPHONY

Every note is played by all four voices, each a little early or late within a time window (heterophony). Each voice's timing drifts smoothly from note to note, so the voices start in unison and wander apart and back.

Knob (Z held)	Sets	LEDs
X	Width of the spread	LED 1 0 ms (unison) · LED 2 50 · LED 3 100 · LED 4 200 · LED 5 300 · LED 6 = 500 ms (default) · not 1 750 · not 2 1 s · not 3 1.5 s · not 4 2 s · not 5 3 s · not 6 4 s
Main	— (not used)
Y	Octave of Voices 3+4	LED 4 = 0 (as BEAT)

In every mode

Inversion — tap Z quickly. Each tap moves on one pattern. The LEDs show it for 1.5 s: LED 1 is always on (a marker); LEDs 2, 3, 4 lit = Voices 2, 3, 4 inverted. To just look without changing it, hold Z half a second and let go.

Tap	Inverted	LEDs lit
(start)	none	1
1	V2	1 2
2	V3	1 3
3	V4	1 4
4	V2 + V4	1 2 4
5	V3 + V4	1 3 4
6	V2 + V3	1 2 3
7	V2 + V3 + V4	1 2 3 4

The mirror point is the first note after Play. Voice 1 is never inverted.

Page 2 — hold Z 1s until the LEDs flash, keep holding:

(Page 1 settings for each mode are noted above)

Knob	Sets	LEDs
Y	Which voice to edit	LED 1–4 = V1–V4
X	That voice's octave	LED 1 −2 · LED 2 −1 · LED 3 = 0 · LED 4 +1 · LED 5 +2
Main	Inversion type	LED 1 = strict (exact mirror: C D E → C B♭ A♭) · LED 2 = tonal (within the scale you play: C D E → C B A)

To set several voices: turn Y to a voice, set X, turn Y to the next voice, set X again. Tip: an inverted voice sits below the line — set it to +1 to bring it back up.

Tonal inversion learns the scale from the pitch classes of the last 32 notes played (kept across Stop/Play). Straight after power-on it only knows the first few notes, so let a phrase that uses the whole scale play through once.

Lookup tables

Delay patterns (X in BEAT, FREE, STEP) — how far behind Voice 1 each voice is, in steps (BEAT), units (FREE) or notes (STEP):

LEDs	V2-V3-V4	LEDs	V2-V3-V4
LED 1	1-2-3	not 1	1-2-4
LED 2	2-4-6 (default)	not 2	2-4-8
LED 3	3-6-9	not 3	2-3-5
LED 4	4-8-12	not 4	3-5-8
LED 5	5-10-15	not 5	1-3-6
LED 6	6-12-18	not 6	3-5-6

Tempo ratios (X in TEMPO) — V2, V3, V4 speed against Voice 1 (in CONVERGE they run the inverse, e.g. 5:4):

LEDs	V2, V3, V4	LEDs	V2, V3, V4
LED 1	15:16, 7:8, 13:16 (gentlest)	not 1	9:10, 4:5, 7:10
LED 2	11:12, 5:6, 3:4	not 2	3:4, 1:2, 1:4
LED 3	7:8, 3:4, 5:8	not 3	2:3, 1:2, 1:3
LED 4	4:5, 3:4, 2:3 (default)	not 4	1:2, 1:3, 1:4
LED 5	5:6, 2:3, 1:2	not 5	1:2, 1:4, 1:8
LED 6	4:5, 3:5, 2:5	not 6	3:4, 9:16, 27:64

Calibrating CV In 1

If you get some tuning issues between the voices, this process wil calibrate four voices.

Patch CV Out 1 → CV In 1.
Hold Z Down and power on; keep holding until the LED bar starts.
The card steps CV Out 1 through −4 V … +4 V (about 4 s, LED bar filling).
All six LEDs lit = saved to flash. LEDs 1 + 6 blinking = failed (check the patch) — the previous calibration is kept.

Repatch your sequencer afterwards.

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