Ravel is a custom firmware for the M-VAVE FM-1 that turns the FM-1 into a pocket groovebox for sound design. It has 8 tracks that synthesize, strike and drum, and that play, excite, and reshape one another

Status: runs on the FM-1 and in the browser emulator. The whole instrument runs in the browser emulator and the desktop simulator, from the same C sources the firmware is built from. The FM-1 firmware is bare metal (no vendor SDK) on the open hardware layer of the Felucca family of community firmwares, and installs from a web installer over USB. It is young: copy your projects to a computer now and then (the emulator's Get from FM-1), and report anything odd on the repository's issues.

What it is

• Synth tracks (T1 to T4), thirteen engines: VA (saw to pulse, supersaw, sync, sub, noise, through-zero FM), CZ (a full Casio CZ: two lines, the eight CZ waves, 8-step DCO, DCW and DCA envelopes, ring and noise modulation, vibrato and a Juno-60 style chorus), HYBRID FM (4 operators, 12 algorithms, a wave per operator and an envelope on the modulators, run through moving formants after the Yamaha FS1R: eight spectral states to morph between, breath through noise bands, and formant sequences that move the timbre on their own clock), PHYS (string, bowed, blown, membrane), FORMANT (vowel filter bank or FOF grains), PARTICLE (pulsar emitters that pull into sync), CHIP (SID-style waves arpeggiating through offsets, then a decompose stage that crushes and breaks the sound apart), WAVE (after the PPG Wave and Waldorf Microwave: two wavetable oscillators, sync, ring and FM, phase warps, a looping wave envelope), LOGIC (oscillators built from function blocks: arithmetic, bit logic and comparators between three sources, then pitch-synchronous grains), ORGAN (a pipe organ played like a synthesizer: ranks by footage, pipes that speak in their own time, chiff, air and wind), MONO (an SH-101-style voice played like a horn: legato, scoops, delayed vibrato), RESIN (a bowed string or a reed, pushed toward breaking down: scrape, flageolet, growl, multiphonics and a QUAKE knob that makes the player's hand shake), TINE (struck and plucked bars and tines: a rusty kalimba with buzzing rings, a marimba or balafon, and an electric piano after the Rhodes).
• Strike tracks (T5, T6), with GRAIN, a small difference in every hit (as on perc tracks): an exciter (click, noise, metal, FM burst, dust, rain, bow, breath, or EXT: another track's sound) strikes a body (ping filters, modal bars, a struck disc or coupled strings), with a transient layer, ring mod and a pitch drop.
• Perc tracks (any track, KIND PERC): 33 drum machines after the Elektron Machinedrum's synthesis families: TRX (analog-style), EFM (FM), P-I (physical models) and GND, each with the Machinedrum's track effects.
• Arpeggiator on any note track (ARP): up, down, up-down, down-up, as played or random, 1/4 to 1/32 of the clock, over up to four octaves, with gate, hold, repeats and chance; it plays held keys, the track's own steps and influence triggers alike.
• COMP (T8, off until you choose it): a glue compressor on the main mix after the SSL G-series bus compressor, with its stepped ratios, attacks and releases (and AUTO), threshold, makeup, a dry mix and a SIDECHAIN that can listen to any track (muted or not) instead of the mix.
• WEFT (any track, KIND WEFT): a voice you patch from twelve blocks, as in Max or Pure Data: PHASE and WAVE oscillators, Serge-style SLOPE, CYCLE and SLEW, LP/BP/HP filters, ADD, MULT, MIX, MIN, MAX and FOLD, logic (COMP, AND, OR, XOR, FLIP), a short DELAY, harmonic BANDS and sample-and-hold; DUST (particles in clumps) and TICK (pings on the tempo's grid); struck resonators (RING, and six-mode SKIN, BAR, PLATE, BELL, HARMS and a FIXED filterbank); SAT, ABS, DIFFUSE and CHAOS for feedback networks; a one-block STRING, CRUSH and EDGE; sequential switches (SW 1>4, SW 4>1); FOLLOW (an envelope follower), SHAPE (waveshapers), CHEBY (a Chebyshev low pass), FORMANT (vowels), a VOCODER, a RINGMOD, coloured NOISE, a RUNGLER (Benjolin-style shift register), LISSA (a Lissajous LFO), a frequency SHIFTer and a DIODE clipper; outputs: AUDIO (blocks mixed into the voice), CLK OUT (a clock any track's sequencer can follow), MOD OUT (a matrix source) and SEQ OUT (steps, jumps, restarts, gates or changes the pattern of another track's sequencer); VIOLENCE sources (V TAP, V HELD, V TURN: how hard the panel is being played); cross-patched with feedback anywhere, input B able to move any block's second setting; built-in pitch, gate, trigger, velocity, noise and LFOs; live scopes on every block; twenty-eight factory patches; a patch library on the FM-1; patched on the FM-1 or in the emulator's drag-and-drop patcher, and shared as files.
• GLITCH LOOPER (any one track, KIND GLITCH): four lanes recorded from the main mix or one track, overdubbing, each with its own level, pitch and speed (pitch and speed apart, by a grain stretch); a threshold to arm a take; quarter slices on the keys that take turns in the order held; PLAY and REC trigs on the steps with sections, Octatrack- and MLR-style. It borrows the effects' memory (it can keep SPACE or DELAY running).
• Influence: an 8 × 8 grid where any track can modulate, trigger, excite, ring, clock, or spark (tap the body of) any other.
• Articulation: onset, continuant and termination stages with curve, overshoot, a loop, a tail and Give (a spring that lets the level lag and bounce), two destinations, its own FILTER ENV, and a library of 32 chainable step envelopes that steps start to move any parameter across the steps.
• Sequencer: each track runs in STEPS or GRAPH mode. Steps: length, rate and direction, parameter locks, microtiming, ratchets that bounce, climb, fall or darken as they roll, conditions, chance, microcuts of the mix with their own shape and size, and a EUCLID page that writes evenly spread hits into the steps. Graph (from Silt): cords set where a playhead goes next, two playheads walk the same graph, each playing notes, only the gate, or only the pitch (so rhythm and melody can take different paths), head 2 can play another track, and each head has a function generator (rise, fall, arch, decay, swell, or an LFO or dust) that moves its speed, times or plus the clock. Plus density arcs, a per-track note interval, scale quantizing, René-style clocking from LFOs or dust, and a two-oscillator master clock. Recording keeps what you play live, chords included (up to four notes on a step), or step by step while stopped (a note or chord a step, rests and back), and each kit lane can run at its own rate.
• Modulation: two LFOs, dust, an 8-slot matrix and 4 macros with 8 destinations each (curves and windows).
• MIDI in over USB and the TRS jack: notes on one channel, any, or channels 1–8 on tracks 1–8; velocity, mod wheel, aftertouch and pitch bend as matrix sources; clock (counted pulse by pulse, so it never drifts), start and stop.
• Buses: a granular tape delay (echoes and a grain cloud from one half-rate tape; wow, flutter, saturation, age, double tracking, freeze), a 12-BIT space (a gritty late-80s rack plate: decay, damp, motion, crunch, low cut), a feedback bus (filter, comb, smear, shift, fold or crush, a band filter in the loop, returning to the master or into a track), a BED of dust on a tuned wood-to-metal body that sinks under busy tracks and rises in the gaps, and master drive with microcuts (even, bouncing or dragging) and punch-in effects on the keys. Each bus page shows the current track's send into it. Every effect starts off: a new project sends nothing into any bus, and a bus with nothing coming in does not run at all.
• Song: patterns A and B per track, 16 scenes that switch or glide over 1–8 bars, a 32-row arrangement, mute and solo, tap tempo, 32 named project slots (compressed on the FM-1), and four banks of your own sounds that PRESETS reaches from any track; projects and sounds move between the emulator and an FM-1 as a .ravel file.

New here? Open the emulator (Opening it), load a demo, press Play, then read The five moves. Everything else is reference.

Contents

The manual

1. Opening it
2. The panel
3. The five moves
4. How the parts connect
5. HOME: tracks and influence (and the GLITCH LOOPER, step by step; WEFT, a voice you patch)
6. EDIT: the voice
7. ENV: articulation
8. LFO: modulation and macros
9. FX: the buses
10. SCL: scale
11. ARP: the arpeggiator
12. SEQ: steps and the graph

On the FM-1: Installing · If the FM-1 will not start

For developers: What's here · Building · The FM-1 build · Licence

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The manual

Everything below works the same in the browser emulator and on the FM-1. The pictures are the real screen, taken from the simulator.

1. Opening it

In a browser. Open ravel-emulator.html. It is one file, works offline and needs no install. Click anywhere or press a key once to start the sound; browsers stay silent until you do. On a computer keyboard, Z X C V B N M play the lowest seven keys in order (F, F♯, G, G♯, A, A♯, B), then A S D F G H J K L ; ' play the white keys from C up, with W E T Y U O P the black keys. [ and ] are OCT- and OCT+, 1–8 choose the track and the space bar is PLAY.

The emulator page has three parts:

• The left panel (the workbench) is a set of shortcuts:
  • pick a demo and press Load;
  • Play and Record;
  • T1–T8 pick a track;
  • Sound chooses the track's kind, engine and a preset;
  • Page ← Back / Forward → steps through the section's pages (the same as turning SELECT, or the ← → keys);
  • Go to jumps straight to a section;
  • Audio in plays a file into the input;
  • Output has a level meter and the volume.
• The FM-1 in the middle is the instrument itself. Everything in this manual is done there.
• The Controls guide and Eight tracks below are short reminders and a level meter for each track. Click a track card to select it; M mutes it.

Using the emulator's controls:

To	Do this
Turn a knob or encoder	Drag it up or down, or scroll on it
Press a button	Click it
Hold a button (for the hold layers)	Right-click or shift-click it; it stays held (lit) until you click it again. Esc lets go of everything.
Play keys	Click or touch them, or use the computer keys A W S E D F T G Y H U J K O L P ; ' (A is middle C, the 5th white key)
Octave	[ and ]
Start or stop	Space
Pick track 1–8	Number keys 1–8
Turn SELECT (next or previous page)	← / → arrow keys
Stop everything at once	Panic / stop all, top right

The page has a safety limiter, so nothing can reach your speakers or interface at full scale. Volume starts at 70.

Projects you save in the emulator are kept in your browser, so they are still there next time on the same computer and browser.

On the FM-1. Install it with the web installer (see Installing on the FM-1). Everything works the same as in the emulator, with these differences:

• MASTER is the output volume (the emulator's Volume slider).
• No audio input. The FM-1's USB carries Ravel's sound to a computer (it shows up as an audio input named "Ravel FM-1" you can record), but nothing comes in. The EXT exciter takes its sound from other tracks.
• Saving pauses the sound for a moment, because the code runs from the same flash the project is written to.
• No Bluetooth.

2. The panel

Control	What it does in Ravel
MASTER	Output volume
SELECT	Moves to the next page (turn right) or back to the previous one (turn left) in the section you are in
ALGORITHM	Picks the track you are working on, T1 to T8. The keys play this track.
PRESETS	Browses the list that belongs to the page: sounds on most pages, the step the knobs edit on SEQ's step pages (STEPS, STEP TIMING, STEP SHAPE, STEP CUT, DRUM STEP) and patterns on its other pages, scenes on SONG, slots on SAVE (projects or sounds), steps on GRAPH, routes on INFLUENCE. The footer tells you which.
KNOB 1–4	Change the four values in the row at the top of the screen, left to right
OCT− / OCT+	Move the keyboard down or up an octave. On SEQ pages they move between step pages (1–16, 17–32, …). On pages with more settings than knobs they move the knobs to the next row instead; those pages show the rows on screen, number the knobs, and the footer says what OCT brings next: a kit's LANE pages (machine parameters, then LEVEL, CHANCE, LENGTH), the CZ's DCO, DCW and DCA envelopes (two stages at a time, then SUS and END), and LFO SHAPE (LFO 1 or LFO 2).
10 section buttons	Each one opens a section (a group of pages). Tap it again for the section's next page.
PLAY	Starts and stops the sequencer
REC	Tap to arm recording on the current track
Keys	Play the current track, or act as steps, scenes or switches depending on the page and on what you hold

The section buttons:

Button	Section	What lives there
HOME	Tracks	All eight tracks at a glance, and the influence grid. Hold HOME on any page for a help screen: what each knob, PRESETS, the keys and OCT do there, and the layers that work everywhere; let go and you're back where you were
EDIT	Voice	The current track's sound: engine, source pages, pitch, filter, skin, insert, mix, sends
ENV	Articulation	How a note starts, holds and ends, the FILTER ENV, and the step envelopes (STEP ENV, LIBRARY)
LFO	Mod	Mod matrix, the two LFOs, dust, macros
FX	Buses	Delay, space, BED, feedback, master
SCL	Scale	Root, scale, transpose, interval
ARP	Arp	The current track's arpeggiator: mode, rate, octaves, hold (also a sustain with the arp off); gate, repeat, chance
SEQ	Steps	Steps, tempo, step timing and shape, track settings, direction, graph and playheads
GLO	Song	Mixers, the clock (tempo first), scenes, arrangement, density arcs, CPU
SAVE	Projects and sounds	Save, load, demos, new project; your own sound bank

Section or layer? A quick tap (less than about half a second) opens the section. Holding a button and using keys or knobs while it is down turns it into a layer instead: SEQ held makes the keys steps, LFO held puts the macros on the knobs, and so on. When you use a button as a layer, letting go of it does not change the page. See Hold layers.

Reading the screen

• Top bar:
  • left: the track (T1–T8, its badge coloured by kind: white synth, slate strike, maroon perc), its kind and engine;
  • right: the page title, and on the FM-1 the audio load (CPU 43% with a thin bar, held a moment at its peak; amber from 75%, red from 90%). The emulator doesn't measure it, so it doesn't show there.
• Value row: a strip divided into four cells, one for each physical knob, always KNOB 1, 2, 3 and 4 in that order. Each cell has a small dial, the name and the value, and a bar showing where it sits in its range; bipolar values have a centre mark. An empty cell keeps its dividers, so you can see which knobs do something on the page. A greyed name and value means that knob does nothing with the track set as it is.
• Picture: what the page does, drawn live (a waveform, a filter curve, the step grid, the graph). Tracks keep their kind's colour in the pictures (their meters, waves and steps); what belongs to no one track (the buses, the graph's two heads, the two WAVE tables) is drawn in white and greys with bone and verdigris.
• Footer:
  • left: what the controls do right now. It changes when you hold a button, so read it whenever you are unsure.
  • right: small dots, one per page in the section, with the current one lit; then, on the FM-1, the battery: three bars, red and empty when it runs low, or a bolt while USB powers it (the reading means little then).
  • Also shown: a play indicator while running, and a red dot when recording is armed.

Short messages ("CAUGHT", "PATTERN B", "SAVED TO 3") flash on the screen when something happens.

3. The five moves (how every page works)

Every page in Ravel works the same way:

1. Press a section button to open the section.
2. Turn SELECT (or tap the same button again) to walk its pages. On FX, tapping FX again jumps to the next bus (DELAY, SPACE, BED, FEEDBACK, MASTER); SELECT still goes page by page.
3. Turn ALGORITHM to choose which track you are editing.
4. Turn KNOB 1–4 to change the four values shown.
5. Turn PRESETS to browse whatever the page holds.

Knobs speed up when you turn them quickly, so a fast turn crosses a whole range and a slow turn moves one step.

Pages appear and disappear. A section only shows the pages that apply to the current track:

• a VA synth has three SOURCE pages, FM has four;
• the graph's HEAD pages only appear when the track is in GRAPH mode, and HEAD 2's pages only when head 2 is on.

So if a page seems to be "skipped", it is hidden because it does not apply to this track. Change the track or the setting and it comes back.

Greyed-out knobs. When a knob does nothing with the track set as it is, its name and value turn grey. For example, on a strike track with the PING body, DAMP, INHARM, GEOMTRY and MODES are grey, because a ping filter has none of those. The value is kept, so it is ready if you change the setup. So are ENGINE and VELO on strike tracks (engines are for synth tracks; strike takes velocity as it comes), T DECAY until TRANS is up, RING F until RING is up, ORDER, RATE and SEED except with the DUST or RAIN exciter, and on PHYS, POSITN for BLOWN and MEMBRAN.

4. How the parts connect

Ravel has 8 tracks. Each track is one of three kinds, and any track can be any kind (HOME › TRACKS › KIND); T8 can also be the COMP, the mix's compressor, any one track the GLITCH LOOPER, and any track a WEFT voice you patch:

Kind	What it is	Default tracks
SYNTH	An oscillator voice with thirteen engines: VA, CZ, HYBRID FM, PHYS, FORMANT, PARTICLE, CHIP, WAVE, LOGIC, ORGAN, MONO, RESIN, TINE. Up to 4 voices.	T1–T4
STRIKE	An exciter hitting a resonant body: drums, metal, wood, rain on glass	T5–T6
PERC	A drum machine: 33 machines after the Elektron Machinedrum (TRX, EFM, P-I, GND). It starts as a KIT, six machines in lanes sequenced together on one track; MODE SINGLE is one machine played by notes.	T7 (a kit), T8 (one drum); any track can be PERC
COMP	T8 only, and only when you choose it: not a voice, but a bus compressor on the main mix (see T8 as COMP)	–
WEFT	A voice you patch from twelve blocks (see WEFT). Any track; four voices shared	–
GLITCH	The GLITCH LOOPER: four lanes of recorded audio, played back and overdubbed (see GLITCH LOOPER). One track at most; the effects buses rest while it is on (it can keep SPACE or DELAY running)	–

How the sound flows:

1. Each track makes sound. On synth, strike and perc tracks the sound goes: source → filter → skin (drive, fold, bits) → insert effect → articulation (the amplitude envelope) → level and pan.
2. The mixer adds the tracks together. Each track also sends some of its sound to the three buses (delay or grains, space, feedback), and the buses return into the mix.
3. The COMP (when T8 is one) squeezes the mix. The master applies drive and microcuts, then a safety limiter, then goes to the output.
4. Influence connects tracks to each other. One track's notes or audio can trigger, modulate, excite, ring or clock another (HOME › INFLUENCE).
5. The sequencer plays every track from its own pattern. The modulation (LFOs, dust, matrix, macros) moves parameters over time. Scenes and the arrangement switch patterns and states.

5. HOME: tracks and influence

TRACKS

The overview shows all eight tracks:

• each track's number and kind;
• a live level meter;
• how many voices it is using;
• along the bottom, the influence routes drawn as lines.

The current track is highlighted.

Knob	Value
1 LEVEL	Track volume, 0–127
2 PAN	−64 left to +63 right
3 KIND	SYNTH, STRIKE or PERC (on T8 also COMP), GLITCH (the GLITCH LOOPER) or WEFT (a voice you patch). Changing it resets the track to that kind's defaults.
4 ENGINE	For synth tracks: VA, CZ, HYBRID FM, PHYS, FORMANT, PARTICLE, CHIP, WAVE, LOGIC, ORGAN, MONO, RESIN, TINE

ALGORITHM picks the track; PRESETS loads a sound of the track's kind.

T8 as COMP: the bus compressor

T8 can be a glue compressor for the whole mix, after the SSL G-series bus compressor. It is off by default (T8 is a drum). To turn it on, choose T8 with ALGORITHM, and on HOME › TRACKS (or EDIT › SOUND) turn KIND to COMP. T8 then plays nothing itself: EDIT keeps its first page, SOUND, with KIND (ENGINE, VOICES and VELO greyed out), and the compressor's two pages follow it; it squeezes the mix (the tracks and the buses' returns) before the master's drive and limiter. To turn it off, turn KIND back on SOUND (or HOME › TRACKS; it is also KNOB 3 on COMP 2).

Page	KNOB 1	KNOB 2	KNOB 3	KNOB 4
COMP	THRESH: −30 to 0 dB	RATIO: 2:1, 4:1, 10:1	ATTACK: 0.1, 0.3, 1, 3, 10, 30 ms	RELEASE: 0.1, 0.3, 0.6, 1.2 s, or AUTO
COMP 2	MAKEUP: 0–15 dB	MIX: 0–100 % (below 100, the dry mix under it: parallel compression)	KIND	S.CHAIN (the sidechain): MIX (the default: it listens to what it squeezes) or T1–T7

SIDECHAIN (S.CHAIN). With a track chosen, the compressor listens to that track instead of the mix, and squeezes the whole mix when it plays: the classic pump of a kick pushing pads and bass down. It hears the track after its own effects but before its LEVEL and mute, so a muted track still works the compressor: a silent "ghost" kick on its own track, at the rhythm you want the mix to breathe, is a common trick. The picture says KEYED BY T1 (and so on).

The meter falls from the top as it squeezes (0 to 20 dB of gain reduction); beside it, the curve it squeezes by, with the mix's level now as a dot. AUTO releases in two stages, as the SSL's does: quickly after a short peak, slowly out of a long squeeze. For glue, start at 2:1 or 4:1, ATTACK 10 or 30 ms, RELEASE AUTO, and lower THRESH until the meter moves 2 to 4 dB on the loudest hits. It costs almost nothing: the level is read once per 16 samples.

The matrix and macros can move its knobs like any track's (THRESH on an LFO pumps). A scene or a sound loaded onto T8 can change its kind like any track's.

GLITCH LOOPER

Turn KIND to GLITCH on any one track (EDIT › SOUND, KNOB 1, or HOME › TRACKS, KNOB 3; turn it back the same way to remove the looper). It plays nothing of its own: it records what you hear into four lanes and plays them back, each lane overdubbing as it records. EDIT keeps its SOUND page (KIND; the other knobs greyed), and the looper's pages follow it.

Step by step

The keys below are counted from the left: black key 1 is the first black key (F#), white key 1 the first white key (F).

Your first loop

1. Get something playing: load a demo (SAVE › DEMO) or your project, and press PLAY.
2. With ALGORITHM, pick a track you aren't using (T8, say). Press EDIT: the first page is SOUND. Turn KNOB 1 (KIND) until it reads GLITCH (if the track had steps, the screen asks you to turn again). The effects stop; the screen's bottom line says FX BUSES REST.
3. Turn SELECT one page to GLITCH LEVEL: four empty lanes.
4. Press black key 1. Lane 1 records (a red line runs along it) and plays what it has recorded, in time.
5. Let it go round once (16 steps, a bar, unless you change LENGTH on SEQ), then press black key 1 again. It stops recording and keeps playing.
6. Mute the tracks you recorded (GLO › MUTE / SOLO, white keys 1–8) to hear the loop on its own, then bring them back in.

Shape it

7. GLITCH LEVEL, GLITCH PITCH and GLITCH SPEED have a knob a lane: PITCH transposes without changing the time, SPEED changes the time (1/4 to 2, or REV) without changing the pitch.
8. Overdub: press black key 1 again while the lane plays and play over it. OVERDUB (GLITCH INPUT, KNOB 3) is how much of the old stays: 127 keeps all of it, 100 (the default) lets it fade a little each pass, 0 replaces it.
9. More lanes: black keys 2–4 record lanes 2–4; black keys 5–8 start and stop lanes 1–4 playing.

Play slices

10. Hold white key 1: lane 1's first quarter plays, round and round, in place of the lane. White keys 1–4 are lane 1's quarters, 5–8 lane 2's, 9–12 lane 3's, 13–16 lane 4's.
11. Hold two or more (even from different lanes): they take turns in the order you pressed them. Let go and the lanes carry on.

Wait for the sound

12. On GLITCH INPUT, turn THRESH (KNOB 2) up. Now black key 1 only arms the lane; it starts writing when the sound gets that loud, so a take starts on the first hit.

Record with reverb (or delay)

13. On GLITCH INPUT, turn LOOPER (KNOB 4) to +SPACE (or +DELAY). The lanes empty and get a little shorter; SPACE keeps running.
14. Send the tracks into SPACE as usual (each track's EDIT › MIX or SENDS) and record from SOURCE MAIN: the reverb goes into the loop.

Sequence it (the transport must be playing)

15. Press SEQ: the GLITCH TRIGS page. KNOB 1 (or black keys 3–6) picks the lane, KNOB 2 the trig: REC or PLAY.
16. With TRIG on REC, tap white key 1: each time the pattern reaches step 1, that lane records the whole loop. Tap it again to remove it.
17. With TRIG on PLAY, tap a step: the lane plays from there. For a section, hold one step and tap another: the section runs from the left one to the right one, both included, whichever you held first (hold 9 and tap 12, or hold 12 and tap 9: steps 9–12). The trig goes on its first step, RANGE (KNOB 3) is set to reach the last, and the keys light along it. A PLAY section plays just those steps of the lane, round and round, until another trig moves it (MLR-style); a REC section records into just those steps. Any other trig of the same lane and kind inside it is removed.

Clear, and get the effects back

18. Hold black key 9 and press a record key (black 1–4) to clear that lane. Press black key 11 twice to clear all four.
19. To have every effect back: LOOPER to OFF (the track keeps its settings and trigs; the loops are gone), or turn KIND back on EDIT › SOUND.

Recordings are not saved with the project: save keeps the GLITCH LOOPER's settings and trigs, and the lanes start empty.

Reference

The memory. The FM-1 has no RAM to spare, so the lanes borrow the effects buses' memory, and the effects whose memory they hold stand still. LOOPER (GLITCH INPUT, KNOB 4) says how much they take:

LOOPER	The effects	A lane holds	16 steps at 120 BPM
ON (the default)	DELAY, FEEDBACK, SPACE and the microcuts rest	about 16 000 samples	about 8 kHz
+SPACE	SPACE keeps running; the rest rest	about 13 300	about 6.7 kHz
+DELAY	DELAY keeps running; the rest rest	about 10 000	about 5 kHz
OFF	all of them run; the looper is silent and its keys and trigs wait	–	–

The lanes are stored 8-bit, spread over the loop's LENGTH: lo-fi on purpose, and a short loop at a quick tempo sounds clearer than a long, slow one. Every change of LOOPER empties the lanes (their memory is laid out again, or handed back), and an effect handed back starts clean. The screen's bottom line says what is running.

Recording with an effect: set LOOPER to +SPACE (or +DELAY), send the tracks into it as usual, and record from MAIN: the reverb (or the echoes) go into the loop. Then, to play with every effect again, turn LOOPER to OFF; the loops are gone, but the track keeps its settings and trigs, ready for the next take. The GLITCH LOOPER's own playback is dry: it sends nothing into the effects.

What it records. SOURCE MAIN (the default) is the main mix, with whatever effect LOOPER keeps running, without the GLITCH LOOPER itself, so it never records its own playback. SOURCE T1–T8 records one track, after its own effects. The FM-1 has no audio input, so the looper can only record Ravel.

Page	KNOB 1	KNOB 2	KNOB 3	KNOB 4
GLITCH LEVEL	LEVEL 1	LEVEL 2	LEVEL 3	LEVEL 4
GLITCH PITCH	PITCH 1 (±24 semitones)	PITCH 2	PITCH 3	PITCH 4
GLITCH SPEED	SPEED 1: 1/4, 1/2, 3/4, 1, 3/2, 2, REV	SPEED 2	SPEED 3	SPEED 4
GLITCH INPUT	SOURCE: MAIN, T1–T8	THRESH: 0 records at once; above 0, an armed lane waits until the sound is that loud	OVERDUB: how much of the old stays under the new (0 replaces it)	LOOPER: OFF, ON, +SPACE, +DELAY (see above)

PITCH and SPEED are apart: SPEED changes how fast the loop runs, and PITCH transposes it without changing its time (a two-grain stretch). Both can be moved by the LFOs and the matrix.

Playing it by hand (with the GLITCH LOOPER's track chosen, on any page but SEQ):

• Black keys 1–4 record lanes 1–4: one tap starts (or arms, with THRESH above 0), the next stops. A lane that records also plays, the loop's whole length, in time.
• Black keys 5–8 start and stop lanes 1–4 playing.
• Hold black key 9 and tap a record key to clear that lane; tap black key 11 twice to clear all four.
• The white keys play slices, in groups of four: keys 1–4 are the four quarters of lane 1, 5–8 of lane 2, and so on. A held slice replaces its lane while it is held. Hold several, even from different lanes, and they play one after another in the order you pressed them, round and round, as the arpeggiator's PLAYED order does with notes.

Sequencing it (SEQ, like the Octatrack's recorder trigs). The steps carry only PLAY and REC trigs, per lane:

Page	KNOB 1	KNOB 2	KNOB 3	KNOB 4
GLITCH TRIGS	LANE: the lane the keys write	TRIG: PLAY or REC	RANGE: how many steps the trig plays or records (0: the whole loop)	LENGTH of the loop
TRIG CHANCE	CHANCE	CONDITN	–	–

• Tap a step to place or remove a trig of the chosen kind on the chosen lane; black keys 3–6 choose the lane.
• Hold a step and tap another to set a section (MLR-style), from the left one to the right one, both included, in either order: REC over steps 5–11 records into them and stops; PLAY over steps 8–14 plays that stretch of the lane, looping it until another trig moves it. The trig sits on the section's first step with its RANGE reaching the last; other trigs of the same lane and kind inside it go. On SEQ the keys light the chosen lane's trigs of the chosen kind (TRIG), each along its section.
• A REC trig with THRESH above 0 waits for the sound before it writes.

The recordings are not saved: a project keeps the GLITCH LOOPER's settings and trigs, and its lanes start empty when it loads or the FM-1 starts. The loop's clock follows the GLITCH LOOPER's sequencer while it plays, and keeps running at the tempo while stopped. On v1.6.0 a project's GLITCH LOOPER loads as a blank synth with its steps cleared; firmware older than that should not open such a project.

WEFT: a voice you patch

A WEFT track has no engine of its own: you build its voice from twelve blocks, the way a Max or Pure Data patch is built from objects, or a modular from modules. Each block does one thing (makes a ramp, reads it as a wave, rises and falls, filters, multiplies, compares, delays, throws particles, rings when struck) to its two inputs, A and B. An input takes the output of any block, the block itself included, or one of the built-in sources, with an amount (−100 to +100). Any track can be WEFT, as many as you like; they share four voices.

Patch it on the FM-1's pages, or with the mouse or a finger in the emulator's WEFT patcher (below), and move patches between the two.

WEFT step by step

Your first WEFT voice

1. Turn ALGORITHM to a track (T1, say) and press EDIT. On SOUND, turn KNOB 1 (KIND) to WEFT. The track starts from the INIT patch: a saw (WAVE) through a low pass (LP), an envelope (SLOPE) opening both, into a VCA (MULT).
2. Play the keys. SELECT one page on is WEFT PLAY: the voice's output as a scope, and four of the patch's settings on the knobs (here CUTOFF, RES, FALL and SHAPE).
3. Turn PRESETS on any WEFT page to hear the twenty-eight factory patches (below). Keep your own on WEFT LIBRARY, the last WEFT page (below).

Patch a block by hand

4. SELECT to WEFT PATCH: the twelve blocks as tiles in three rows, each with its number, its type and a live scope of its output. Cords run from a block's output (right) to an input (left: A above, B below); a coloured dot on an input is a built-in source (bone: PITCH; red: GATE or TRIG; verdigris: an LFO).
5. KNOB 1 (BLOCK) picks a block, KNOB 2 (TYPE) sets what it is (an empty block becomes one; the voice is heard from the first block you make), KNOB 3 (IN A) picks where input A comes from and KNOB 4 its amount.
6. SELECT to WEFT BLOCK for the same block close up: KNOB 1–2 are input B and its amount, KNOB 3–4 the block's two settings. The picture shows what comes in on A and B, the block, what goes out, and where it goes. Black key 1 sets what input B does: its own job (the table below), or B MOVES: B turns the block's second setting instead (a filter's RES, a ring's DECAY, a clip's BIAS…), up and down from where the knob leaves it, at audio rate. The B label says which; on WEFT PATCH a B port that moves a setting is bone.
7. SELECT to WEFT MAP: KNOB 1 picks one of PLAY's four knobs, KNOB 2 the setting it turns (any block's), KNOB 3 OUT, the block the voice is heard from (AUTO, the default: the last block that isn't an output block, or, if the patch has AUDIO blocks, just them), KNOB 4 RUN: KEYS (the default: the patch plays while a key is held, and its tail) or ALWAYS (one voice runs on its own, no key needed: a drone, a self-clocking network, a patch that drives other tracks; the GATE and TRIG sources still follow the keys, so leave them out of what should run, and PITCH is the last note played). The track's LEVEL is on MIX. VOICES (1 or 2) is on SOUND.

Example: a plucked string from nothing

8. Start from INIT. Set blocks 1–5 as below, each input not mentioned to - (none). On WEFT PATCH: block 1 SLOPE, input A TRIG (a pulse at each note), and on WEFT BLOCK its RISE 0, FALL about 30: a click of an envelope.
9. Block 2 MULT: A = NOISE, B = block 1. A burst of noise.
10. Block 3 ADD: A = block 2, B = block 5 (a cord back: feedback). Block 4 DELAY: A = block 3, TIME 0 (the note's own period). Block 5 LP: A = block 4, CUTOFF high. The burst circles round the delay, a little darker each time: a string, at the note you play.
11. On WEFT MAP set OUT to block 4. That is Karplus-Strong; the factory PLUCK is the same, with an envelope to stop it when the key is let go.

Any setting of any block also takes step locks (hold SEQ and a step, turn the knob on WEFT BLOCK or PLAY), the matrix and macros, like any parameter: they are track parameters, two a block.

Example: dust on a drum skin

12. Load DUST SKIN (PRESETS) and hold a key: block 1 DUST throws particles (DENSITY a second, CLUSTER how much each one makes more follow, so they come in clumps that spread out), block 2 HOLD takes a new random pitch at each, and block 3 SKIN rings at it, a drum skin's six modes. DIFFUSE smears the hits, and a loop back through MULT (moved by a slow CYCLE) and SAT keeps some of the smear going. On PLAY, KNOB 1–4 are DENSITY, CLUSTER, the skin's DECAY and the smear's AMOUNT.
13. Resonators in a loop sing: a ring at its pitch passes almost all of what it gets, so feeding a SKIN or a RING back into itself makes a tone that holds. Keep the loop outside the resonator (as here), or the amount small, and put SAT in it.

The blocks

All signals run about −1 to +1; SLOPE and SLEW run 0 to 1 (envelopes). An input left empty reads 0 (MULT's B reads 1, so MULT alone is a level). "High" from the logic blocks is +LEVEL, "low" −LEVEL.

Block	What it does	Input A	Input B	Settings
PHASE	a ramp from −1 to +1 at the note × RATIO: the core of an oscillator	FM (through-zero: the rate swings either way)	SYNC: resets the ramp as B rises through 0 (hard sync)	RATIO (1/4 … 16), FINE (±1 semitone; 64 = none)
WAVE	reads a phase as a wave. With nothing on A it runs its own phase at the note: an oscillator on its own	PHASE (e.g. a PHASE block, for sync or FM)	PM: added to the phase (phase modulation)	SHAPE (sine → triangle → saw → square), WARP (bends the phase, the Casio CZ's trick; 64 = none)
SLOPE	rises while A is high, holds, falls when it drops (Serge's function generator). With nothing on A it follows the note's gate	GATE (a pulse: an AD envelope)	TIME: faster (up) or slower (down)	RISE, FALL (0.5 ms … 8 s)
CYCLE	rises and falls on its own: an LFO, or an oscillator at fast RATE	RATE (exponential)	SYNC: restarts it	RATE (0.02 Hz … 2.6 kHz), SKEW (which way takes longer: saw ↔ triangle ↔ ramp)
SLEW	follows A, taking RISE to go up and FALL to come down (portamento, smoothing, envelope following)	IN	TIME	RISE, FALL
LP · BP · HP	a state-variable filter: low, band or high pass	IN	CUTOFF, five octaves each way (audio rate: filter FM)	CUTOFF (20 Hz … 20 kHz), RES
ADD	A + B + OFFSET	A	B	OFFSET (64 = 0), GAIN (64 = ×1)
MULT	A × (B + OFFSET): a VCA, or ring modulation	A	B	OFFSET, GAIN
MIX	A into B by BLEND	A	B	BLEND, GAIN
MIN · MAX	the lower / higher of A and B + OFFSET (clipping, rectifying)	A	B	OFFSET, GAIN
FOLD	A, driven round a sine: folds back on itself as it grows (wavefolding)	IN	DRIVE (more folding)

Built-in sources (an input's menu, after the twelve blocks): PITCH (the note, ±1 over four octaves round middle C), GATE (high while the key is held), TRIG (one sample at each note), VEL, NOISE (white), LFO 1, LFO 2 (the global LFOs), WHEEL (MIDI mod wheel), ONE (a constant 1, for offsets), SW 1–4 (a SW 1>4's four outs), LIS Y (a LISSA's Y) and the three VIOLENCE sources, how hard the panel itself is being played, 0 … 1 each: V TAP (each key struck adds to it; it falls away over about half a second, so hammering the keys pushes it up), V HELD (how many keys are held down: six or more is 1) and V TURN (each knob detent adds to it; it falls away faster). Patch them into whichever blocks should answer: a DUST's DENSITY, a SAT's DRIVE, a SEQ OUT's TRIG.

Order and feedback. The blocks run in their order, 1 to 12, once a sample. A block reads the blocks before it from this sample, and itself and the blocks after it from the one before. So any cord can go anywhere, and a loop (a cord back, verdigris on the screen) is feedback one sample late, as in Max's gen~ with history. A patch can't run away: the voice is gently limited, and a filter that blows up starts over.

Voices and cost. WEFT tracks share four voices; a track takes one or two (VOICES on SOUND; with one, the voice carries on from note to note, its oscillators and delays unbroken). Each voice runs the blocks it can be heard through at the full sample rate, so a big patch costs about as much as three or four voices of a synth engine: watch GLO › CPU (its WEFT bar). A block that nothing heard or sent out depends on doesn't run at all; slow CYCLEs and LISSAs (under about 50 Hz) are worked out every eighth sample and smoothed; the whole voice loop and its bigger blocks run from RAM (on the FM-1, code run from the flash waits for it); on the FM-1, WEFT voices share the second core with the other voices. A released voice ends once it has been quiet a moment (a patch with no envelope after its last block rings on until 12 s after release). When the overload guard is holding voices back, WEFT keeps to two (one when it has to ease more). A patch using more than eight blocks plays one voice, whatever VOICES says (WEFT MAP shows it), until its cost on the FM-1 is measured. A patch with RUN ALWAYS, or with CLK OUT, MOD OUT or SEQ OUT, keeps one voice running all the time, notes or not, so its clock, its source and its sequencer moves go on (the lowest track with one is the one heard, if several have them); it takes one of the four for as long as the block is there.

Factory patches (PRESETS on the WEFT pages): INIT (saw, low pass, one envelope), SYNC LEAD (hard sync, a slow LFO on the synced ramp), DX BELL (two-operator FM at 7:1, its index falling), PLUCK (Karplus-Strong), CMOS XOR (two ramps XORed, a FLIP sub-octave, scanned BANDS), PHASE DIST (an envelope bending a sine, CZ-style), DRONE (two saws a fifth apart, a slowly swept band pass), TANGLE (a triangle phase-modulated by its own folded, filtered self), SPECTRA (noise through four harmonic bands, scanned), S&H BLIPS (a clock sampling noise into the pitch, each tick an envelope), DUST SKIN (clumped particles on a drum skin, smeared, fed back), PLONK (a click of noise strikes a bar, its pitch falling), TOM SKIN (a pulse on a skin, its brightness moved by velocity with B MOVES), PINGS (two clocks on the tempo's grid strike tuned rings while a key is held), TICK CLOCK (sixteenths with a CLK OUT: set another track's CLOCK to WEFT), DUST MOD (smoothed clumps of dust as the matrix's WEFT source; silent), SCATTER (each particle of dust sent at random by SW 1>4 to one of four rings, crushed), PING SWITCH (a clock picks, tick by tick, between two rings, a string and its clipped self with SW 4>1), KS STRING (a click of noise into STRING), CHAOS STRING (a logistic map plucks a string at each zero crossing and sets its pitch), BENJOLIN (after Rob Hordijk's: two free oscillators, a rungler clocked by one and fed by the other bending both, their comparison through a resonant filter), VOWELS (a saw through FORMANT, the vowel wandering with a LISSA), ROBOT VOX (a vowel-shaped saw speaking through a square an octave down: VOCODER), RUNGLE PINGS (a rungler stepping the pitch of a ring struck in sixteenths, a CHEBY after), LISSA DRONE (two saws, a CHEBY and a RINGMOD moved by a LISSA's X and Y), WIND (dark noise through two band passes swept by a LISSA), VIOLENCE (play the panel hard: strikes thicken the DUST that steps T3 and drive the clip, a knob turned unsettles the CHAOS that jumps T4 about, a hard strike restarts T2, held keys bend a ring; give T2–T4 some steps and press PLAY) and THREE LOOPS (no oscillators, after Jaap Vink's feedback patches at the Institute of Sonology: a low pass, a folder and a short delay in one loop; a SHIFT, a DIODE and a smear in a second fed a little of the first; the two ring-modulated and crushed; the second loop's level darkening the first and moving the shift; hold a key).

WEFT LIBRARY: load, save and delete patches on the FM-1

The last WEFT page (SELECT on from WEFT MAP) is the track's patch library. The top line says how many of your patches the current bank holds and how many of its 32 slots are free (any sound takes a slot). The list holds your patches first (the WEFT sounds in that bank, A1…, marked YOURS), then + EMPTY (the bank's first free slot: where a new save goes), then, below a line, the factory patches (F1–F28, marked FACTORY). The factory patches are the same in every bank: they are built in, can be loaded anywhere and take no room. Your patches are kept as WEFT sounds in the sound banks, so they travel with Send to FM-1 and the emulator's sound files, and are kept when you load another project.

• KNOB 1 (PATCH) (or PRESETS) moves through the list; KNOB 2 (BANK) picks bank A–D.
• Black key 1: LOAD the highlighted patch onto the track.
• SAVE (the button) or black key 2: SAVE the track's patch. On one of yours it overwrites it (press twice); anywhere else (+ NEW, or a factory patch, as when you have just made something from the default patch) it goes into the first empty slot at once, named PATCH n, and the cursor moves onto it so KNOB 3–4 can name it.
• Black key 3: DELETE the highlighted patch of yours; press it again to confirm. Factory patches can't be deleted.
• Black key 4: INIT starts the track again from the INIT patch (a saw, a low pass, an envelope); black key 5: CLEAR empties every block, to build from nothing. Each asks for a second press.
• KNOB 3 (CURSOR) and KNOB 4 (LETTER) rename the highlighted patch of yours, a letter at a time (the cursor is underlined); the name is kept a moment after you stop turning.
• The white keys still play the track. ON THIS TRACK at the bottom names the patch the track is playing.

The WEFT patcher (in the emulator)

Under the instrument in the emulator, the WEFT patcher shows the current track's patch as a diagram you can play with:

• Make this track WEFT turns the current track into one (or choose Weft (patch) under Sound).
• Drag from a block's output (the dot on its right) to an input (A or B, on its left) to patch; a cord back to an earlier block is drawn dashed in green (feedback). Click a cord to take it out. Drag a block by its title to move it (the layout is only for you; it is kept in your browser).
• Click a block to edit it on the right: its TYPE, each input's source (blocks and built-ins) and amount, its two settings, and whether it is the voice's output. Clicking also picks it on the FM-1's screen in the emulator.
• Patch loads a factory patch; Output, Voices and KNOB 1–4 on WEFT PLAY are the MAP page's settings.
• Each block shows its output live while you play. Everything you change plays at once, and the emulator's own FM-1 screen follows (and the other way round).
• Input B moves … (under the settings) is B MOVES.
• On a phone the blocks stack two a row, larger to touch.

Getting a patch onto your FM-1. A patch belongs to its track, so it travels with the project and in your sound banks: SAVE the project (or Save sound… in the emulator's Sound section), then Send to FM-1 (Projects & sounds). On the FM-1 you can go on editing it on the WEFT pages. Export patch saves it as a small .weft.json file to keep or share; Import patch puts one onto the current track. The file is plain JSON, block types and sources by name:

{"format": "ravel-weft", "version": 2, "name": "PLUCK",
 "blocks": [{"type": "SLOPE", "a": "TRIG", "amtA": 100, "b": null, "amtB": 0, "p1": 0, "p2": 34, "bMoves": false}, ...],
 "out": 7, "map": [9, 6, 2, 12], "voices": 2}

A source is a block number (1–12) or a built-in's name; p1 and p2 are the settings (0–127, or a list's entry from 0: RATIO, DIV, ORDER, RANGE, CURVE, LENGTH, TRACK, MODE); bMoves, input B moving the second setting; out the block heard (0: none, 13: AUTO); map holds 1 + a setting number (block n's settings are 2(n−1) and 2(n−1)+1), 0 for none. Version 1 files (eight blocks) import as they are.

INFLUENCE

An 8 × 8 grid: rows are sources, columns are targets. Each filled cell is a route, coloured by type.

1. Turn ALGORITHM to the source track (its row is highlighted).
2. Turn PRESETS to the target column (the box moves along the row).
3. Turn KNOB 1 (ROUTE) to choose what the route does. An empty cell says "TURN K1 TO MAKE A ROUTE".
4. Set the other knobs. They change name to suit the route.

Route	What happens	KNOB 2	KNOB 3	KNOB 4
MOD	The source's envelope moves one of the target's parameters, every time the source plays	AMOUNT (±)	PARAM: which of the target's parameters	–
TRIG	Each note on the source also plays the target, with the same pitch	AMOUNT (below 0 plays the target softer)	DELAY: 0–16 steps later	CHANCE: 0–100 %
EXCITE	The source's audio feeds into the target's body or string (best into a strike or PHYS track)	AMOUNT	–	–
CLOCK	Each source note moves the target's sequencer one step (René-style: rhythm drives rhythm)	AMOUNT	–	–
RING	Ring modulates the target with the source's audio	AMOUNT	–	–
SPARK	Each source hit taps the target's body: a strike track rings at its last note, with no exciter and no attack of its own, and plays no note (so it starts no chain of its own). Only strike tracks can be sparked	AMOUNT: how hard the tap	–	–

To remove a route, turn KNOB 1 back to -.

A trigger chain never plays the same track twice in one pass, so routes can form loops safely (T1 triggers T2, which triggers T1).

6. EDIT: the voice

All pages here act on the current track (ALGORITHM). PRESETS browses sounds for the track's kind on every voice page; the sound's name flashes on screen. A preset doesn't touch the track's sends into the effects (FX): they stay where you set them.

Page	KNOB 1	KNOB 2	KNOB 3	KNOB 4
SOUND	KIND	ENGINE	VOICES (mono, 2, 3, 4)	VELO: how much key velocity changes the level
SOURCE 1–4	the engine's own controls, see below
OSC MIX	each oscillator's level, side by side: VA OSC LVL, SUB, NOISE · FM LEVEL1–4 · WAVE LEVEL 1, ASIC · CHIP OSC LVL, SUB · MONO SAW, PULSE, SUB, NOISE

OSC MIX appears on engines with more than one sound source. OSC LVL (LEVEL1 on FM, LEVEL 1 on WAVE) is the first oscillator's own level, new here; the others are the engine's existing level knobs, shown together (they stay on the SOURCE pages too). The CZ's two lines are levelled by their DCA envelopes, ORGAN's by its rank footages. | PITCH | PITCH (±24 semitones) | FINE (±50 cents) | GLIDE | VCF KEY: the filter's cutoff (or a Z filter's morph) follows the note | | FILTER | FILTER type: LADDER, LOWPASS, BANDPASS, HIGHPASS, LPG, MS-20, SH-101, and six Z filters (Z VOWEL, Z TALK, Z PHASER, Z PEAKS, Z SWEEP, Z METAL) five XT filters (XT LP24, XT BP24, XT NOTCH, XT S&H, XT SHAPE) and SEM | CUTOFF (Hz); on a Z filter, MORPH | RESO; on a Z filter, XFORM | ENV>CUT: how much the FILTER ENV opens the filter (±); the same setting as on ENV › FENV ROUTE, so turning either moves both | | SKIN | DRIVE (saturation of everything the track plays at once: 0 by default, so chords stay clean; turn it up to make them break up together) | FOLD (wavefolding) | BITS (bit reduction) | – | | SKIN 2 | BITMASK (digital grit) | DEREZ (sample-rate reduction) | GRAIN (strike and perc tracks): each hit a little different, see below | – | | INSERT | INSERT effect: OFF, COMB, SHIFT, CRUSH, SMEAR | TUNE: on COMB its note (C4 at the middle, a semitone a step); on SHIFT the shift | AMOUNT | MIX | | MIX | LEVEL | PAN | DELAY send | SPACE send | | SENDS | FEEDBK send | DELAY send | SPACE send | – |

MS-20 is hot and dirty: a two-pole filter whose resonance runs through clipping diodes, with the input driven. Turned up, it barks, then screams. SH-101 is round and liquid: four smooth stages whose resonance sings rather than bites, and keeps its bass as it rises.

The Z filters morph, in the manner of E-mu's Z-plane filters (Morpheus, the Audity, the later samplers). Each is twelve poles: six sections, peaks, dips and slopes, laid out at the four corners of a square. CUTOFF becomes MORPH, which moves across the square one way, and RESO becomes XFORM, which moves it the other. In between, every peak glides at once, so the whole shape turns into the next one rather than a single cutoff moving. The filter envelope (ENV), VCF KEY, the LFOs and the matrix move MORPH like any cutoff. The FILTER picture draws the real response as it morphs. The shapes are Ravel's own:

Type	MORPH (0 to 127)	XFORM (0 to 127)
Z VOWEL	"ah" to "ee"	a lower, softer voice to a higher, sharper one
Z TALK	"oo" to "ae": a talk box, best moved by the envelope	to "aw" and "er": tighter, more nasal
Z PHASER	six notches sweeping up from low to high	from plain notches to notch-and-peak pairs: a phaser with its feedback up
Z PEAKS	six resonant peaks rising together	from broad and glassy to narrow and ringing
Z SWEEP	closed (a steep twelve-pole lowpass) to open	from smooth to a resonant peak riding the slope
Z METAL	one set of clangorous, inharmonic peaks to another	from struck to long and ringing

Try the TALK BOX, PHASE PAD, Z VOX and Z SWEEP presets. The Z filters are on synth tracks, on any engine.

SEM is after the Oberheim SEM: a single 12 dB state-variable filter, open and creamy rather than fat, whose resonance rises to a vocal peak but never quite self-oscillates. Choosing it adds a SEM page after FILTER: LP-HP sweeps continuously from low pass (0) through a notch (64) to high pass (127), and the matrix and LFOs can move it; BP switches to its band pass, which grows louder as RESO rises (LP-HP is then greyed); CUTOFF and RESO are repeated there. Try the SEM BRASS and SEM NOTCH presets.

The XT filters are digital filters in the manner of the Waldorf Microwave II/XT's: XT LP24 is a clean four-pole lowpass whose resonance rings sharp and glassy, XT BP24 a four-pole bandpass, XT NOTCH cuts a hole at CUTOFF (RESO widens and deepens it), XT S&H samples and holds the sound at a rate CUTOFF sets (a sample-rate reducer that follows the keys with VCF KEY; RESO keeps more of the raw steps) and XT SHAPE is a wave shaper, CUTOFF driving it and RESO folding it further. They suit the WAVE engine but work on every synth engine.

The filter belongs to synth voices. On strike tracks the FILTER page's knobs are greyed out.

LPG is a low-pass gate: the filter closes as the note fades, so sounds get darker as they die away (good for plucks and Buchla-style bongos).

Changing ENGINE resets the SOURCE values to that engine's defaults. Use PRESETS to start from a finished sound instead.

GRAIN (EDIT › SKIN 2, on strike and perc tracks) makes each hit slightly different from the last: a little sharper or flatter (up to half a semitone), a little louder or softer, now and then darker or shorter. Most hits move a little and a few a lot, the way a hand never strikes twice the same. It changes nothing about which steps play or when: it is texture, so sixteen hats sound like sixteen hits instead of one copied. On a kit it acts on every lane.

The thirteen synth engines (SOURCE pages)

VA (virtual analog): the familiar subtractive oscillator, and more.

SOURCE 1	SOURCE 2	SOURCE 3
WAVE: saw through to pulse	SUB: sub-oscillator level	SYNC: hard-sync sweep
PW: pulse width	NOISE level	DRIFT: slow analog wander
SUPER: 1–7 stacked oscillators (supersaw)	TZFM: through-zero FM depth
DETUNE: spread of the stack	FMRATIO: modulator ratio (1/2 to 7)

CZ: a full Casio CZ (the CZ-101, 1000, 3000, 5000 and CZ-1 all share this voice). It works as the CZ's own sound chip does: a cosine read through a bent phase, where DCW is how bent it is (at 0 every wave is a sine). Each note plays one or two lines, and each line has two waves and three 8-step envelopes: DCO (pitch), DCW (waveform) and DCA (level). Ravel's filter, skin, inserts, LFOs and matrix all still work on top.

General settings, on the SOURCE pages:

SOURCE 1	SOURCE 2 (detune: line 2)	SOURCE 3 (vibrato)	SOURCE 4
LINE: 1, 2, 1+1' (line 1 twice, the second detuned), 1+2' (both lines, line 2 detuned)	DETUNE: + or -	VIB WAV: TRI, SQUARE, UP, DOWN	DCW +-: shifts both lines' DCW; give it an LFO in the matrix to sweep the timbre (the CZ itself could not)
OCTAVE: -1, 0, +1	DT OCT: 0–3 octaves	DELAY before it starts (0–99)	FOAM: takes the fundamental out, leaves the sidebands
MOD: OFF, RING (line 2 times line 1), NOISE (line 2's pitch kicked by noise)	DT NOTE: 0–11 semitones	RATE (0–99)	VEL DCW: how much a softer touch closes DCW (0–9, CZ-1 style)
CHORUS: OFF, I, II, I+II (Juno-60 style)	DT FINE: 0–60 (60 = a semitone)	DEPTH (0–99; 0 = none)	–

Then, per line (LINE 1, LINE 2):

KNOB 1	KNOB 2	KNOB 3	KNOB 4
WAVE 1: SAW, SQUARE, PULSE, DBL SIN, SAW PLS, RESO 1 (saw window), RESO 2 (triangle), RESO 3 (trapezoid)	WAVE 2: OFF, or a second wave	DCA KF: the level envelope runs faster on higher notes (0–9)	DCW KF: higher notes are duller (0–9)

And the envelopes, DCO 1, DCW 1, DCA 1 (and DCO 2, DCW 2, DCA 2):

Each envelope page holds all eight stages. OCT+ and OCT− move the four knobs through five rows; the picture lights the two stages on the knobs and marks them with the knob numbers (1 2, 3 4), and the footer says what OCT+ brings next. PRESETS still picks a sound.

OCT row	KNOB 1	KNOB 2	KNOB 3	KNOB 4
1 (stages 1–2)	RATE 1: how fast stage 1 moves (0–99)	LEVEL 1: the level it moves to (0–99)	RATE 2	LEVEL 2
2 (stages 3–4)	RATE 3	LEVEL 3	RATE 4	LEVEL 4
3 (stages 5–6)	RATE 5	LEVEL 5	RATE 6	LEVEL 6
4 (stages 7–8)	RATE 7	LEVEL 7	RATE 8	LEVEL 8
5	SUS: the stage the envelope holds while the key is down (OFF, 1–8)	END: its last stage (1–8)	–	–

Stages after END are drawn dim: they keep their settings but don't play until END reaches them (set END to 8 to use all eight).

• How an envelope runs: from step 1, each step moves at its RATE to its LEVEL, then the next step starts. At the SUS step it waits while the key is held; when you let go it goes on from the step after SUS. It stops at END. Rates and levels follow the CZ's own curves: rate 99 is a few milliseconds, rate 0 almost forever; DCA levels are on the CZ's logarithmic scale.
• DCO levels: up to 63 the pitch rises in 6.25-cent steps (63 is almost 4 semitones); from 64 it jumps in 2-semitone steps (64 is 8 semitones, 99 is 78). The DCO envelope can only raise the pitch, as on the CZ.
• Two waves on a line alternate cycle by cycle, so the note sounds an octave lower with a mix of both characters (the CZ's "cascade"). Two RESO waves cannot be combined, as on the CZ.
• RESO waves are a sine whose frequency rises with DCW, restarting every cycle under a falling window: like sweeping a resonant filter, with no filter.
• High notes narrow DCW automatically, as the CZ does, so thin pulses stay audible.
• The DCA is the level envelope. On a CZ track the ARTICULATION pages' shape knobs are greyed out; the envelope's DESTINATIONS and the influence routes follow the DCA instead; the filter has its own FILTER ENV.
• The pictures: LINE pages draw the line's two cycles at its brightest DCW. Envelope pages draw the 8 stages, the SUS and END points, the two stages on the knobs (white, numbered with their knobs) and where the playing note is (amber dots).
• Presets: CZ BRASS, CZ BELL (ring-modulated lines a twelfth apart), CZ STRINGS, RESO SWEEP, CZ BASS, NOISE HIT and FOAM.
• Projects from before the CZ load with each CZ track set to a plain CZ tone.

HYBRID FM: 4 operators, and after them a body of formants (after the Yamaha FS1R's formant synthesis). With FORM at OFF it is a plain four-operator FM synth.

SOURCE 1	SOURCE 2	SOURCE 3	SOURCE 4
ALGO: 12 routings (shown as 1>2>3>4 and so on; > means "modulates", + means "mixed")	RATIO3	LEVEL4	WAVE4
FEEDBK: operator 1 feedback	RATIO4	WAVE1	MOD DEC: how fast the modulators fade (the classic FM "pluck")
RATIO1	LEVEL2	WAVE2	TZFM: through-zero FM
RATIO2	LEVEL3	WAVE3	VEL MOD: velocity brightens the sound

Each operator can be SINE, TRI, SAW, SQUARE, HALF, ABS, QUART or BITS.

MOD ENV	FORMANTS	FSEQ
MOD ATK: how long the modulators take to rise at each note (0: at once)	FORM: OFF, or the spectral state the formants start from: OO, AH, EE (vowels), BOW (a cello-like wooden body), REED (a sax-like throat), METAL (narrow, ringing, inharmonic), HOLLOW (a tube), NASAL	FSEQ: OFF, or a formant sequence: WAH, TALK, BREATH, BLOOM, STUTTER, ORBIT, SCRAPE, DROP
MOD DEC (the same as on SOURCE 4): how fast they fall	MORPH: from FORM toward the next state (NASAL's next is OO)	F RATE: how long each of its eight frames lasts, on the tempo (2 BAR … 1/32), or SCRUB: MORPH moves through the sequence instead
MOD SUS: where they settle (32, a quarter, is the classic FM pluck; 127 holds them)	AIR: breath, scrape and hiss: noise through two bands that move with the formants	F DEPTH: how far the sequence moves the formants, and how much of its level and breath it adds
VEL MOD (the same as on SOURCE 4)	BODY: how much of the operators goes through the formants (0: none, only the breath)	–

How it works. The operators make the tone; three formants (resonant band passes at each state's frequencies, widths and levels) shape it, the way a mouth, a cello's body or a metal tube does; AIR adds noise through two more bands. Each state is a whole spectral identity, and moving between them (MORPH, the sequence) glides each formant to its partner in the next state, frequencies through octaves and levels through decibels, so the sound changes shape without jumping. The formants' level follows the operators', so turning FORM or MORPH doesn't make it jump in level, and a soft limit keeps narrow METAL resonances in hand. A formant sequence starts again at each note: its eight frames each move the formants (from FORM, as far as F DEPTH says), set a level and add breath; WAH, TALK, STUTTER and SCRAPE loop, BREATH, BLOOM and DROP play once a note, ORBIT goes back and forth through all eight states. The note, the amplitude envelope and the sequence each keep their own time, so a held note can travel from a bowed string to a throat to metal. FORM, MORPH, AIR and the rest are ordinary parameters: the matrix, the LFOs, the macros and step locks move them too (an LFO on MORPH is a slow vowel). Unlike some FM synths, Ravel never thins the modulation on high notes for you (neither the FS1R nor the DX7 does it on its own); turn the levels down as you play higher if it gets harsh.

Factory sounds (PRESETS): FM PIANO, FM BELLS and FM GROWL are plain FM; FM VOX (vowels that TALK in eighths), FM BOW (a bowed wooden body with SCRAPE), BREATH REED (a reed that starts as breath), STEEL TUBE (inharmonic ratios in a METAL body, slowly orbiting), ORGANISM (a hollow, slowly turning spectral creature) and FM STUTTER (a sequence that gates the voice in sixteenths) use the formants.

PHYS (physical modelling): a virtual instrument that you strike, bow or blow.

SOURCE 1	SOURCE 2
MODEL: STRING (plucked), BOWED, BLOWN, MEMBRAN (drum skin)	EXCITE: how hard it is played: pluck strength, bow speed, breath
BRIGHT: brightness of the excitation	INHARM: detunes the overtones (metallic); on BOWED, lighter bow pressure (scratchier, airier)
DAMP: how quickly highs die	BODY: resonance of the body (not MEMBRAN)
POSITN: where it is plucked or bowed (STRING, BOWED)	DECAY

BOWED and BLOWN keep sounding for as long as the key is held, like a violin or a clarinet. BLOWN speaks an octave lower in character (a clarinet's hollow, odd-harmonic tone) but plays the note you press.

FORMANT: vowels and voices.

SOURCE 1	SOURCE 2
VOWEL: sweeps A-E-I-O-U	BREATH: air in the voice
SHIFT: moves the formants (smaller or bigger "throat")	GLOTTAL: the shape of the pulse
WIDTH of the formants	SPREAD: stereo or choir spread
MODE: FILTER (a filter bank on a pulse) or FOF (grain-based, more vocal)	VIBRATO

PARTICLE: pulsars. Short bursts of a waveform at the note's pitch that can pull each other into sync.

SOURCE 1	SOURCE 2
TABLE: SINE, GLASS, REED, VOICE, BELL, BITS, NOISE, DROP	COUPLE: how strongly the emitters pull into sync
DUTY: burst length (short = buzzy, long = tonal)	MASK: drop bursts at random
EMIT: 1–3 emitters	FORMANT: the burst's own pitch
RATIO between emitters	SCATTER: timing randomness

CHIP: a glitchy chiptune voice, after the Syntakt's SY CHIP. A SID-style oscillator steps through the note you play and up to three offsets at RATE, so one voice plays a fast arpeggio, a chord or a "complex voice". A square sub oscillator sits under it, and a decompose stage after it reduces, crushes and breaks the sound apart.

SOURCE 1	SOURCE 2	SOURCE 3	SOURCE 4 (decompose)
WAVE: TRI, SAW, PULSE, NOISE (the SID's noise register), SAW&PUL (the SID's combined wave), RING (a ring-modulated triangle), PWM (the width sweeps by itself), KICK and SNARE (drum tables)	OF2: the arp's second note, in semitones	SUB: a square sub oscillator on the note you play (it does not follow the arp)	SRR: sample-rate reduction (aliasing, grit)
PW: pulse width (on RING, the ring partner's ratio; on PWM, how far it sweeps)	OF3: the third note	SUB OCT: the sub's octave, -3 to +1	CRUSH: bits, 16 (clean) down to 1
RATE: how fast the arp steps, 2–128 steps a second (classic chip arps are around 50)	OF4: the fourth note	SYNC: the main oscillator restarts with the sub (hard sync), so as the arp moves the notes, the timbre sweeps	DECOMP: how often the sound breaks
MODE: UP, DOWN, PINGPNG, RANDOM, ONCE (up through the notes, then stays)	STEPS: how many of the root, OF2, OF3 and OF4 the arp walks (1 = no arp)	OVER: overdrive	FRAG: the size of each piece, 1.5–46 ms

• The arp: for a minor chord, set OF2 +3, OF3 +7, OF4 +12 and STEPS 4. Multiples of 12 jump octaves. RATE, MODE and the offsets grey out while STEPS is 1.
• Sync: with SYNC on and SUB OCT at -1, the sub holds the root while the arp's notes become synced, tearing timbres over it (the SYNC ARP preset). SUB OCT greys out while SUB is 0 and SYNC is off.
• Decompose: the voice keeps its last 46 ms. At the end of each fragment, DECOMP is the chance that the next one breaks: the last fragment repeats, plays backwards, drops out, has its bits flipped, or plays at double speed. FRAG greys out while DECOMP is 0.
• Presets: CHIP ARP, SID BASS (through the MS-20 filter), CHIP KICK, CHIP SNARE, DECOMPOSED and SYNC ARP.

WAVE: a wavetable synth after the PPG Wave and the Waldorf Microwave. Two oscillators each read a wavetable: 8 key waves, with POS moving through 64 positions between them. Osc 1 can sync, ring-modulate or frequency-modulate osc 2, both read through a phase warp (after Serum's), and a mixer adds a sweet saturation as you push it. The wave envelope sweeps the positions in a loop, as the Microwave's does. ASIC dials in the hardware: from smooth to the PPG's stepping to the early Microwave's sizzle. The 20 tables are Ravel's own, built in the families the PPG made famous; none come from a PPG or Waldorf ROM.

SOURCE 1	SOURCE 2	SOURCE 3	SOURCE 4
TABLE 1: osc 1's wavetable	SEMI 2: osc 2's interval, ±24 semitones	XMOD: OFF, SYNC (osc 2 restarts with osc 1), RING, FM (osc 1 bends osc 2's phase), SYNC+FM	WAVE ENV: OFF, or one of 32 shapes (PLUCK, SWELL, STAIRS and the rest) that sweeps both positions
POS 1: where in the table (0–63)	DETUNE: osc 2 a little sharp	XM AMT: how much	WE AMT: how far it sweeps (±63 positions)
TABLE 2: osc 2's wavetable	MIX: osc 1 to osc 2 (0 = osc 1 alone)	WARP: OFF, SYNC, BEND, PWM, MIRROR, REMAP 2, REMAP 4, SQUEEZE, FLIP, QUANT	WE TIME: one pass of the wave envelope
POS 2	SAT: the mixer's saturation	WARP AMT	VELO: velocity sensitivity (on WAVE it lives here; its place on SOUND holds MIX)

• The tables: PPG SWEEP (sine to saw, harmonic by harmonic), RESONANT (a resonant peak climbing), PULSE (wide to thin), SYNC (a synced sweep), VOICES (vowels), ORGAN (drawbar settings), BELLS, FORMANT, DIGITAL (bit patterns), SQR TO SAW, PARTIALS (one harmonic walking up), OCTAVES, FM (an index sweep), BRASS, STRINGS, PPG HARD, RANDOM, CHOIR, E-PIANO and WAVEFOLD.
• The warps: SYNC squeezes several cycles into one; BEND leans the wave left or right; PWM squeezes its first half; MIRROR plays it forward then back; REMAP 2 and 4 blend in the wave read two or four times a cycle; SQUEEZE pinches it toward the middle; FLIP turns the end of the cycle upside down; QUANT steps the phase (bit-crushed reading).
• The wave envelope loops while the key is held, then finishes its pass. Pair it with a slow WE TIME for evolving pads, or a fast one with STUTTER or STAIRS UP for rhythmic wave sequences. POS 1 and POS 2 are modulation destinations too: an LFO on POS is the classic PPG sweep.
• Greyed knobs: osc 2 is only heard through MIX (or RING, which multiplies it into osc 1), so osc 2's knobs grey out while MIX is 0 and XMOD isn't RING, and so does XM AMT for SYNC and FM, which change osc 2: turn MIX up to hear them. XM AMT also greys while XMOD is off; WARP AMT while WARP is off; WE AMT and WE TIME while WAVE ENV is off.
• Where MIX, VELO and ASIC sit: on a WAVE track, SOUND's fourth knob is MIX (so bringing in table 2 is one turn from the first page), VELO moves to SOURCE 4's fourth knob, and ASIC sits on OSC MIX beside LEVEL 1: 0 smooth; 1–63 the positions step through 64 whole waves (the PPG's zipper); 64–127 raw, unsmoothed reading, a truncated phase and a coarser output (sizzle). MIX also stays on SOURCE 2.
• The picture: table 1's waves stacked back to front, the one playing lit in POS 1's knob colour. With MIX up, table 2 is drawn below it the same way, lit in POS 2's colour, each stack half as deep.
• Presets: PPG PAD, WAVE BELLS, MW SYNC, DIGI BASS, VOX SWEEP and REMAP STEP.

LOGIC: oscillators built out of function blocks, after Kurzweil's VAST, whose FUNs compute a function of two signals, and E-mu's patch-cord functions. Three simple sources play: A on the note, B and C at musical ratios of it. OP 1 combines A and B, then OP 2 combines that with C. The functions range from arithmetic to bit logic, so the result can be anything from a soft sum to a broken digital pattern that repeats at the sources' common period. A pitch-synchronous grain stage can then turn it into a granular wave: every cycle it plays a grain of the voice's own last few milliseconds.

SOURCE 1	SOURCE 2	SOURCE 3	SOURCE 4
A WAVE: SAW, TRI, SQUARE, SINE, PULSE, NOISE	C WAVE	BITS: the word size the bit operators and QUANT work in, 1–12 (fewer is cruder)	SMOOTH: rounds off the hard edges (the engine also runs at twice the rate to keep them cleaner)
B RATIO: 1/4 to 16 times A	OP 1: how A and B combine	PW: the width of any PULSE source	GRAIN: 0 off; short grains leave gaps (pulsar-like), long ones overlap into a cloud
B WAVE	OP 2: how OP 1's result and C combine	B DRIFT: B up to 30 cents off its ratio, so the pattern slowly turns	G SPRAY: how far back, at random, each grain starts
C RATIO	OP 2 AMT: how much of OP 2 (0 = OP 1 alone)	DRY A: mixes A itself back in	G PITCH: the grains' content transposed, ±24 semitones (the period stays on the note)

• The functions: A+B (a sum), A*B (ring modulation), MIN and MAX (the lower or higher of the two), AND, OR, XOR and NAND (the two as BITS-bit numbers, combined bit by bit), A>B (a comparator: high where A is above B, so two slightly detuned sources make a pulse whose width sweeps), GATE (A only while B is high), DIFF (how far apart they are), QUANT (A in steps that B sets), MOD (A wrapped around a size B sets), SIN(A+B) (a sine of the sum: phase modulation) and A(B) (A's wave read at the position B gives: waveshaping).
• Where to start: XOR or NAND between a SAW and a TRI at a ratio of 3/2 or 2, then fewer BITS for a cruder pattern. A>B between a SINE and a TRI at ratio 1 with a little B DRIFT gives a slowly breathing pulse. Ratios that aren't whole numbers make the pattern repeat at a lower common period, so the pitch can drop: 3/2 sounds an octave down, for example.
• Greyed knobs: C, OP 2 and C RATIO grey out while OP 2 AMT is 0; BITS while no bit operator or QUANT is in use; PW while no source is PULSE; G SPRAY and G PITCH while GRAIN is 0.
• Presets: LOGIC XOR, COMPARATOR, GRAIN VOX and BIT CRUNCH.

ORGAN: a pipe organ played like a synthesizer, after the euphoric, breathing organ records of Maxime Denuc (Nachthorn, made on a computer-controlled church organ). Seven ranks of pipes, one per footage, sound together over one stop family, and each pipe behaves like a pipe: it speaks a moment after the key, comes in slightly flat and with a puff of air (the chiff), and the wind that feeds it is never quite steady. The pipe spectra are Ravel's own, from harmonic recipes; there are no samples. The church is the SPACE bus: set its MODE to CLOUDS and turn DECAY up for the long, stone-room tail, and give the track plenty of SPACE send (the ORGAN presets do).

SOURCE 1	SOURCE 2	SOURCE 3	SOURCE 4
STOP: FLUTE (stopped, nearly pure), NACHTHORN (a wide open flute, hollow and soft), PRINCIPAL (the bright, even organ tone), GAMBA (a string stop), TRUMPET (a reed)	2 2/3': the twelfth (a fifth over the 4')	CHIFF: the puff of air as each pipe starts	WIND: the air supply wavers, pitch and level, and pipes sit a few cents apart
16': an octave down	2': two octaves up	SPEECH: how long a pipe takes to speak, 10 to 150 ms	TREMLNT: the tremulant, a throb in level and pitch
8': the pitch you play	1 3/5': the tierce (two octaves and a third up)	SPREAD: how far apart the ranks start, up to 35 ms	TREM RT: its speed, 3 to 9 Hz
4': an octave up	1': three octaves up	AIR: a breath under the tone	CELESTE: a second 8' rank tuned sharp, so it beats (a voix céleste)

• Registration: the seven footage knobs are the drawstops: pull out 8' and 4' for a clear voice, add 2 2/3' and 2' for a bright, singing mixture, 16' for weight. Ranks too high for a note fall silent, as real pipes run out.
• Playing it: organs don't respond to how hard you play, so VELO starts at 0. The track's ENV is the swell around it all: leave ATTACK short and let SPEECH do the onset; RELEASE about 100 ms is a pipe letting go. The sequencer's interlocking patterns (two playheads in GRAPH mode, INTERVAL, scenes changing registration via the macros) do what the record's pattern-based organ playing does.
• Presets: INFINITE, PLENUM, VOX CELESTE, FLUTE 4' and TROMPETTE.

MONO: a monosynth after the Roland SH-101, played like a wind or bowed instrument, after the way Dorian Concept phrases it. One oscillator, as on the 101: saw, pulse and sub all come from the same source, so nothing detunes or thickens. Choosing MONO sets the track up as the 101 does it: one voice, the SH-101 filter, key tracking full, cutoff about 1.1 kHz, resonance about 12%, the envelope opening the filter by about half, and a bowed-or-plucked envelope (22 ms attack, 260 ms decay, sustain about half, 120 ms release).

SOURCE 1	SOURCE 2	SOURCE 3	SOURCE 4
SAW: its level	NOISE	SCOOP T: how quickly the scoop arrives	VEL>CUT: a harder note opens the filter further
PULSE	PW: the pulse's width	VIBRATO: depth, up to 50 cents	DRIFT: the pitch breathes a few cents
SUB: the sub oscillator's level	PWM: the vibrato's LFO moves the width	VIB RATE: 1 to 9 Hz	RETRIG: LEGATO (overlapping notes slur: the envelope carries on and GLIDE slides) or ALWAYS (every note starts again)
SUB OCT: -1 OCT, -2 OCT, -2 PULSE (a quarter-width pulse, as on the 101)	SCOOP: a detached note starts below and bends up into pitch, up to 3 semitones	VIB DLY: the vibrato fades in after this long, up to 1.5 s	DRIVE: pushes the oscillator into the filter

• Playing it: overlap notes for slurred phrases (the envelope doesn't restart and GLIDE carries the pitch), lift between notes to articulate them (each starts again, with its scoop). A little vibrato that waits before it starts, and VELO with VEL>CUT, make held notes feel blown or bowed. For layered parts, record one mono line, then another on a second MONO track, as Dorian Concept builds his from many single passes.
• Presets: ORGANIC SAW (the settings above with a hint of vibrato), WOODWIND, CELLO LINE, RUBBER BASS and SCOOP LEAD.

RESIN: a bowed string or a reed, built to be played hard. Where PHYS models a well-behaved instrument, RESIN is about the edges: the bow pressed until it scrapes, a harmonic touched lightly, a reed overblown into a growl or a split multiphonic. Each note is one player, with vibrato built in, and the QUAKE knob shakes the player's hand: the pressure and pitch waver more and more, and at the top the note squeals and breaks. MODEL chooses BOW (a bowed string: the bow sticks and slips on the string, and a wooden body rings with it) or HORN (a reed on a bore: the breath pushes the reed, which opens and closes the tube). Changing MODEL sets the other knobs to that model's defaults; their names change with it.

	SOURCE 1	SOURCE 2	SOURCE 3	SOURCE 4
BOW	MODEL	SCRAPE: noise and grit as the bow slips, more with pressure	VIB RT: vibrato rate, 3 to 9 Hz	QUAKE: the hand shakes; pressure and pitch waver, then squeal
	PRESS: bow pressure; past about three quarters, the tone breaks into a raw crunch	HARMON: touch the string lightly at its middle, for the flageolet an octave up	VIB DP: vibrato depth, up to 60 cents	BOW ATK: how quickly the bow gets moving
	SPEED: bow speed, the loudness and brightness	BODY: how much the wooden body rings	ONSET: how long the vibrato takes to arrive, up to 2.5 s	ROSIN: grip; more rosin bites harder
	POSITN: where the bow meets the string, from the bridge (glassy) to over the fingerboard (soft)	SIZE: violin to cello to bass, the body's resonances	DRIFT: the pitch wanders a few cents	HISS: the bow hair's noise
HORN	MODEL	GROWL: singing into the horn; the breath beats at half the pitch	(as BOW)	QUAKE
	PRESS: breath pressure; more overblows	MULTI: a second reflection in the bore, which splits the note into a multiphonic		ATTACK: how quickly the breath arrives
	REED: the reed's stiffness, soft and buzzy to hard and pure	THROAT: the player's throat, a resonance from 250 Hz to 2 kHz		KEYS: the click of the keys at each note
	BORE: where along the bore the reed sits, which colours the tone	SIZE: the bore, small and bright to large and dark		AIR: breath noise

• Playing it: the filter is open by default; shape the note with the volume envelope (a slow attack and long release for a bowed line) and VELO. Use one voice and GLIDE for a single player sliding between notes. QUAKE is the performance knob: put it on an LFO, the matrix or a step envelope (STEP ENV) for a hand that gives out on certain steps.
• Presets: WRAITH (a low cello, pressed hard, with wide slow vibrato and drift), UPSTAIRS (a frantic, scraping violin line, one voice gliding), RESIN VIOLIN (a cleaner violin), FOGHORN (a low, overblown reed) and THROAT SAX (a growling, sung-into reed).

TINE: things that are struck or plucked and then ring: metal tines and wooden bars. Each note is a handful of resonant modes (the bar's or tine's own overtones, which are not the harmonics of a string) set ringing by a short strike; a harder PLUCK, MALLET or HAMMER is a shorter strike, which reaches the higher modes. Choosing TINE opens the track up for it: four voices, the filter open, the envelope held at full sustain so the instrument decays by itself, and velocity at 100. MODEL chooses KALIMBA, MARIMBA or EPIANO; changing it sets the other knobs to that model's defaults, and their names change with it.

	SOURCE 1	SOURCE 2	SOURCE 3	SOURCE 4
KALIMBA	MODEL	RUST: old iron tines, out of true: stray partials that die fast, grit in the pluck, a slow beat between the tine's two swings	BOX: the wooden box's resonance	DETUNE: each note a little off, as hand-tuned tines are, up to 40 cents
	PLUCK: how sharply the thumb lets go	BUZZ: the metal rings (or bottle caps) on the tines, rattling	HOLE: the sound hole, covered (lower, darker) to open	BEND: a hard pluck starts sharp and settles
	DECAY: how long the tines ring	RATTLE: how readily the rings rattle; low, only on hard plucks	WAH: a hand opening and closing the hole, 1 to 8 Hz (0 off)	DAMP: how fast a released note stops (0 lets it ring)
	TONE: how long the high partials last	THICK: thick tines, fuller and lower in their overtones	THUMB: the thumbnail's click	DRIFT: the pitch wanders a few cents
MARIMBA	MODEL	POSITN: where the mallet lands, from the centre (pure) toward the end (more overtones)	ROLL: held notes are rolled, struck again and again (0 off)	DETUNE
	MALLET: soft yarn to hard	TUBE: the resonator tube under each bar, which carries the fundamental	ROLL RT: 5 to 24 strokes a second	HUMAN: an uneven roll
	DECAY	WOOD: the bar's wood, darker to brighter	BUZZ: a balafon's gourds, their membranes buzzing	DAMP
	TONE	STICK: the mallet's click	RATTLE: how readily the gourds buzz	DRIFT
EPIANO	MODEL	BELL: the tine's bright, quick high partial	TREM: tremolo depth (0 off)	DETUNE
	HAMMER: felt soft to hard	BARK: how hard a hard note drives the pickup, for the growl	TREM RT: 1.5 to 9 Hz	KEY OFF: the dampers' noise as a key is let go
	DECAY	PICKUP: how far off centre the tine swings past its pickup: more of the second harmonic	DRIVE: the amp breaking up	DAMP: how fast the dampers stop a released note
	TONE

• Playing it: TINE answers velocity: harder notes are brighter, a kalimba's rings rattle and an electric piano barks. With DAMP at 0 notes ring on after release, like a kalimba or a marimba without dampers; raise it for an electric piano's dampers.
• Presets: THUMB PIANO, NAIL KALIMBA (thick, rusty tines with loud rings, an octave down), HAND WAH, MARIMBA, MARIMBA ROLL, BALAFON, SUITCASE (an electric piano with tremolo), GLASS TINE (all bell, little bark) and BARKING EP.

Strike tracks (SOURCE pages)

A strike is an exciter (what hits) and a body (what rings).

SOURCE 1	SOURCE 2	SOURCE 3	SOURCE 4
EXCITER: CLICK, NOISE, METAL, FM, DUST, RAIN, BOW, BLOW, EXT (only from outside; DUST and RAIN can take the LFO section's DUST instead, below)	DAMP	ORDER: how the modes are laid out	RING F: ring-mod frequency
BODY: PING (filters), MODAL (bars and bells), DISC (cymbals, plates), STRINGS (coupled strings)	INHARM: how un-harmonic the modes are	RATE: for DUST and RAIN, how often grains fall	RING amount
DECAY	GEOMTRY: the shape of the body	TRANS: level of the attack transient	P DROP: pitch drop at the hit (toms, kicks)
TONE: brightness	MODES: 2–8 resonances	T DECAY: length of the transient	SEED: a different random variation

With EXT as the exciter, the track makes no strike of its own: the body rings only from what comes in from outside. That is another track's sound through an EXCITE route (HOME › INFLUENCE), the feedback bus returning into this track, or, in the emulator, a file under Audio in. If nothing is coming in, the SOURCE page says so, and you will hear only the attack layer and the inserts, the same on every note. The body's pitch still follows the notes, so a track exciting it through an EXCITE route rings at the note you play.

Perc tracks (SOURCE pages)

A PERC track is a drum machine after the Elektron Machinedrum. Its 33 machines come from the Machinedrum's four synthesis families. Elektron never published how the Machinedrum makes its sounds, so these are Ravel's own designs, built from what the Machinedrum's manual documents: each machine has the manual's parameters, in its order, doing what the manual says they do. They are not sample-perfect copies; the sampled E12 and ROM machines are left out.

A PERC track has two MODEs (EDIT › SOUND, KNOB 2). It starts as a KIT: six machines in lanes, sequenced together on the one track (see Kits below). SINGLE is one machine played by notes, on the SOURCE pages:

• SOURCE 1, KNOB 1: MACHINE. Choosing a machine loads its own defaults.
• The rest of SOURCE 1 and SOURCE 2: the machine's own eight parameters (A–H on the Machinedrum). A machine with fewer leaves the rest greyed out.
• SOURCE 3 and 4: the Machinedrum's track effects. AMD and AMF (amplitude modulation: depth and rate, up to audio rates), EQF and EQG (a one-band EQ: frequency and boost or cut), FLTF, FLTW and FLTQ (the band filter: a high-pass at FLTF and a low-pass FLTW above it; FLTF at 0 turns the high-pass off, FLTW at 127 the low-pass, FLTQ adds resonance to both). The Machinedrum's SRR and DIST are the track's own DEREZ and DRIVE on EDIT › SKIN.
• Playing it: the key you play transposes every pitched machine (C4 plays it at its PTCH setting). VELO sets how much velocity changes the level. The machines make their own envelopes, so the ENV pages grey out; a hit plays out whatever the key does. VOICES: MONO (each hit chokes the last, as on the Machinedrum) or 2.

Family	Machines	What they are
TRX	BD, B2, SD, XT, CP, RS, CB, CH, OH, CY, MA, CL, XC	Analog-style drums in the TR tradition: sines with pitch ramps, filtered noise, square-wave metal
EFM	BD, SD, XT, CP, RS, CB, HH, CY	Two-operator FM with feedback: from realistic drums to clangs and chaos
P-I	BD, SD, MT, RS, ML, MA, HH, RC, CC	Physical models: membranes, bars and cymbals, ringing as resonators struck by a mallet
GND	SN, NS, IM	A sine with a pitch ramp, noise, and a programmable impulse

The machines and their parameters

Machine	A	B	C	D	E	F	G	H
TRX-BD bass drum	PTCH	DEC	RAMP	RDEC	STRT	NOIS	HARM	CLIP
TRX-B2 bass drum 2	PTCH	DEC	RAMP	HOLD	TICK	NOIS	DIRT	DIST
TRX-SD snare	PTCH	DEC	BUMP	BENV	SNAP	TONE	TUNE	CLIP
TRX-XT tom	PTCH	DEC	RAMP	RDEC	DAMP	DIST	DTYP	–
TRX-CP clap	CLPY	TONE	HARD	RICH	RATE	ROOM	RSIZ	RTUN
TRX-RS rim shot	PTCH	DEC	DIST	–	–	–	–	–
TRX-CB cow bell	PTCH	DEC	ENH	DAMP	TONE	BUMP	–	–
TRX-CH / OH hihats	GAP	DEC	HPF	LPF	MTAL	–	–	–
TRX-CY cymbal	RICH	DEC	TOP	TTUN	SIZE	PEAK	–	–
TRX-MA maracas	ATT	SUS	REV	DAMP	RATL	RTYP	TONE	HARD
TRX-CL claves	PTCH	DEC	DUAL	ENH	TUNE	CLIC	–	–
TRX-XC conga	PTCH	DEC	RAMP	RDEC	DAMP	DIST	DTYP	–
EFM-BD	PTCH	DEC	RAMP	RDEC	MOD

• What they mean: PTCH pitch, DEC decay, RAMP and RDEC a pitch drop and how fast it falls, BUMP and BENV a pitch kick at the start and its length, STRT, TICK, CLIC and SNAP a harder start, NOIS noise at the start, HOLD how long the level holds, HARM extra harmonics, CLIP, DIST and DTYP distortion and its hardness, DIRT fewer bits, TONE and TUNE the colour and detune, DAMP a shorter tail. Clap: CLPY how many claps, HARD sharper ones, RICH a wider band, RATE their spacing, ROOM, RSIZ and RTUN a room after them. Hats: GAP how far apart the metal's tones sit, HPF and LPF the filters, MTAL more metal than noise. Cymbal: RICH, TOP and TTUN the top end and its tuning, SIZE, PEAK an edge. Maracas: ATT and SUS the shake, REV backwards, RATL and RTYP the rattle and its colour.
• EFM: MOD is the FM depth, MFRQ the modulator's frequency (low ratios are tonal, high and odd ones clang), MDEC how quickly the FM fades, MFB and FB feedback (grit, then noise). NOIS and NDEC add noise (snare), CLPS and CDEC repeat the hit (clap), SNAR, SPTC, SDEC and SMOD a second FM pair for a snare timbre (rim shot), TREM and TFRQ a tremolo.
• P-I: HARD a harder hit, HAMR a softer mallet, TENS the pitch bend of a tight skin hit hard, DAMP damping, TUNE how the skin is tuned, SIZE the drum's size, POS where it is struck (centre to edge), RING metal that rings on, RVOL and RDEC the snare wires, GRNS and GLEN the maracas' grains and their length, CLSN the two hats touching, AG and AU more or fewer highs, BR the lows, CLOS and GRAB when the hat closes or a hand grabs the cymbal (127: never).

Kits: six drums on one track

A PERC track starts as a KIT: six lanes, each its own machine with its own sound, all sequenced together on that one track, so a full rhythm takes one track and leaves the others free. The kit's six sounds live inside the track: they are its lanes, not other tracks. (MODE SINGLE turns the track back into one machine played by notes. Changing MODE, or turning a track into or out of a kit by KIND or a preset, starts its steps clean, since notes and lane hits can't read each other; if the track has steps, the first turn only warns, and turning again after a moment does it.)

Editing a kit: one page per lane. Each of the six sounds is edited like a track of its own, on EDIT › LANE 1 to LANE 6. On EDIT, black keys 3–8 jump straight to lanes 1–6 (in other sections they do nothing on a kit) (black keys 1 and 2 stay patterns A and B). A LANE page shows tabs for the six lanes, the lane's machine and family, and every setting it has, in one list like a file browser's details view: the machine's eight parameters, then LEVEL, CHANCE, LENGTH and RATE, each with its bar and value.

• PRESETS chooses the lane's machine (any of the 33; each loads its own defaults).
• The knobs work through the list a row at a time: OCT- and OCT+ move the knobs to the next group (parameters 1–4, parameters 5–8, then LEVEL, CHANCE, LENGTH and RATE). The rows the knobs are on are lit and numbered 1–4 in the list.
• LEVEL is the lane's level in the kit. CHANCE is how likely the lane plays its hits. LENGTH is the lane's own loop (TRK follows the track's LENGTH; any other length runs against it: a 12-step hat over a 16-step kick shifts every bar).
• RATE is the lane's own speed against the track's: X1/4, X1/3, X1/2, X2/3, TRK (the track's), X3/2, X2, X3 or X4. A hat at X2 runs through its steps twice as fast as the kick (sixteenths over eighths, or 32nds as rolls); a lane at X2/3 or X3/2 plays triplets against straight steps; X1/2 stretches a lane's pattern over twice the time. Each lane keeps its own place, wrapping at its own LENGTH, and its hits fall between the track's steps where the rate puts them. Lanes at a rate of their own play forward. The DRUM page marks a lane's rate under its name when it isn't TRK.
• Shared by the whole kit: EDIT › KIT FX (AMD, AMF, EQF, EQG) and KIT FILTER (FLTF, FLTW, FLTQ), SKIN (DEREZ is the Machinedrum's SRR), INSERT, MIX and SENDS. A kit has no PITCH or synth FILTER page: each machine has its own pitch and tone.

SEQ is the drum sequencer, and the only place the lanes are drawn as steps. On a kit track SEQ opens on the DRUM page instead of STEPS: all six lanes over sixteen steps, the chosen lane in red, accents white, ratchets marked above, locked steps marked with a dot, each lane's playhead in teal. The note pages (STEPS, STEP SHAPE, the graphs) are hidden on a kit, since a drum hit has no note or length. Every kit SEQ page draws the lanes: STEP TIMING keeps MICRO, R CURVE and CONDITN (a step's timing is shared by the lanes on it), and TRACK keeps LENGTH, RATE and CLOCK. A kit's ratchets are set per lane on DRUM STEP only.

• In SEQ, black keys 3–8 choose the lane you are sequencing, and the white keys are its sixteen steps: one tap puts a hit there, the next tap clears it (and its locks). OCT- and OCT+ page through longer patterns.
• The DRUM pages:

Page	KNOB 1	KNOB 2	KNOB 3	KNOB 4
DRUM	LANE	LENGTH of the lane's loop (as on its LANE page)	RATE of the lane, against the track's (as on its LANE page)	CHANCE
DRUM STEP (hold a step)	ACCENT: the chosen lane's hit on this step plays at full force	VELO	CHANCE	RATCHET: the chosen lane rolls on this step (1 = no roll; lanes rolling on one step share the count)

• Parameter locks. Go to a lane's LANE page, hold SEQ and a step key, and turn a knob: that value (a machine parameter, or LEVEL) is locked for that lane on that step only, and the knob shows the locked value while the step is held. A teal dot marks the step on DRUM. A lock on an empty step puts the lane's hit there. Each kit holds 48 locks; clearing a hit clears its locks. The kit-wide sound (KIT FX, KIT FILTER, SKIN, the insert) locks the usual way.

• Playing it live: outside SEQ, the white keys play the lanes, 1–6 and again (key 7 is lane 1). With REC armed, what you play is recorded into the lanes.

• A step's velocity, chance, timing and condition are shared by the lanes that play on it; each lane adds its own CHANCE. Each lane is one voice: a new hit cuts its last.

• SWING is on GLO › CLOCK (it was DRUM's fourth knob before lanes had their own RATE).

• EUCLID (the last SEQ page) writes evenly spread hits into the chosen lane; R CURVE and R MOVE (STEP TIMING) shape its rolls.

• Presets: TRX KIT (kick, snare, hats, clap, rim; the kit a new PERC track starts with), EFM KIT, PI KIT and MD MIX KIT (machines from every family).

• Presets: TRX KICK, TRX SNARE, TRX CLAP, TRX HAT, TRX OPEN HAT, TRX COWBELL, EFM KICK, EFM SNARE, EFM HAT, EFM BELL, PI KICK, PI SNARE, PI TOM, PI RIDE, PI SHAKER, METALLICA, GND SUB and IMPULSE.

7. ENV: articulation

Each track has two envelopes. The volume envelope (ENVELOPE, ONSET, LOOP / TAIL, DESTINATIONS) shapes the level and can move two more parameters. The FILTER ENV (three pages after it) opens and closes the filter.

The volume envelope is in three stages, named after how speech is described: the onset (how a sound starts), the continuant (how it holds) and the termination (how it ends). The first page holds the four times and the level you reach for most, attack, decay, sustain and release; the pages after it shape them. The picture draws the shape as you turn the knobs.

Page	KNOB 1	KNOB 2	KNOB 3	KNOB 4
ENVELOPE	ATTACK time (0.5 ms to 8 s)	DECAY time	SUSTAIN level	RELEASE time
ONSET	CURVE: − is a fast swell, + a slow one	OVERSHT: the attack overshoots and settles (a "bite")	GIVE: a spring in the level. It lags and bounces instead of moving straight.	–
LOOP / TAIL	LOOP: repeats the attack and decay while held (a rhythmic flutter; higher is faster)	TAIL: a quiet tail after the release (room for reverbs to bloom)	–	–

(VELO, velocity sensitivity, is on EDIT › SOUND.) | DESTINATIONS | DEST 1: any parameter of this track | AMOUNT 1 (±) | DEST 2 | AMOUNT 2 (±) |

DESTINATIONS lets the envelope move up to two more parameters, such as FM's LEVEL2 or CZ's DCW +-, so the timbre changes with the note.

FILTER ENV

The filter has its own envelope: delay, attack, hold, decay, sustain and release, with a bend on the attack and one on the falls, a loop and a speed. ENV>CUT sets how far it moves the cutoff, up or down (+40 on a new track). It is the same setting as on EDIT › FILTER, so turning either moves both. The envelope can also move one more thing of the track's, F DEST, by F AMT: with F LOOP on it is an LFO of the track's own, started by each note, where the two LFOS are shared by all tracks.

Page	KNOB 1	KNOB 2	KNOB 3	KNOB 4
FILTER ENV	F ATK: attack time (0.5 ms to 8 s)	F DEC: decay time	F SUS: sustain level	F REL: release time
FENV SHAPE	F DELAY: a wait before the attack	F HOLD: how long it stays at the top before the decay	A BEND: the attack's curve, + exponential (slow, then a rush), − logarithmic (a rush, then slow)	D BEND: the decay's and release's curve, + exponential (a fast fall, a long tail), − logarithmic
FENV LOOP	F LOOP: ON runs delay, attack, hold and decay round again while the key is held (with SUSTAIN at 0 it is a filter LFO that starts with the note)	F RATE: every stage faster (+) or slower (−), up to 16 times	–	–
FENV ROUTE	ENV>CUT: how far it moves the cutoff (±)	F DEST: a second destination, any of the track's modulation destinations (pitch, pan, drive, an engine's knobs, the volume envelope's times…)	F AMT: how far it moves F DEST (±; 0 off)	VCF KEY (also on PITCH)

• The picture draws the whole envelope with its bends, marks the loop when it is on, and shows the playing note as a dot.
• Which tracks: synth tracks. With the LPG the filter follows the volume envelope instead, so these pages grey out there, unless F AMT sends the envelope somewhere: then it runs for F DEST. The CZ engine uses it like any other.
• F DEST and F AMT: the newest note's envelope, 0 to its peak, moves F DEST up by F AMT (or down, with F AMT below 0), as the volume envelope's DEST 1 and 2 do. The picture shows where it goes (INTO PAN +20, say). F DEST steps only through what can be moved.
• Moving it: F ATK, F DEC, F SUS, F REL, F RATE, ENV>CUT and F AMT are modulation destinations, so an LFO or the matrix can deepen the track's own one.
• Older projects and sounds load with a FILTER ENV copied from their volume envelope, so they sound as they did (the one envelope used to drive both). The factory presets do the same. The SHAPE envelopes of earlier versions are gone; a project that used one plays the classic volume envelope.

STEP ENV and the LIBRARY

The LIBRARY holds 32 step envelopes: shapes a step starts, that move one parameter across that step and on through the steps after it. A filter blip on one step, a fold that climbs over four, a pitch that drops on the last step of a bar. One number on a step calls up a whole motion, and envelopes can chain into each other for longer, more complicated moves.

STEP ENV says where they go, one destination per track:

Page	KNOB 1	KNOB 2	KNOB 3	KNOB 4
STEP ENV	SE DEST: the parameter it moves (any modulation destination of the track)	SE DEPTH: how far (±)	SE NOTE: OFF, or an envelope every note starts when its step names none	–

• Starting one: set a step's ENV on SEQ › STEP SHAPE (or hold SEQ and ENV, hold the step's key and turn KNOB 1). When that step plays, its envelope starts from the beginning and replaces the one running.
• Carrying on: steps without an ENV leave the running envelope alone, so a long envelope or a chain moves through them. Set SE NOTE to have every such note start an envelope instead.
• At the end an envelope loops back to one of its segments, or hands over to its NEXT (a chain: the next one starts from where the last ended), or holds its last level. Stopping the sequencer puts the parameter back where its knob is.
• The picture on STEP ENV draws the envelope playing on the track, with a dot where it is.

Editing an envelope (LIBRARY): PRESETS picks the envelope (1–32). OCT− / OCT+ step through its rows; the picture marks the segment on the knobs.

Row	KNOB 1	KNOB 2	KNOB 3	KNOB 4
Segment 1–8	LEVEL it goes to (0–127)	TIME it takes: in steps, to an eighth of a step (0 = a jump), or 0.5 ms to 8 s in FREE time	BEND: + exponential (slow, then a rush), − logarithmic (a rush, then slow)	SEGS: how many segments it has (1–8)
The envelope's own	START level	TIME: STEPS (synced to the track, the default) or FREE	LOOP: OFF, or back to segment 1–8 at the end	NEXT: NONE, or the envelope (1–32) that takes over

Editing a segment past the last one adds it. The twelve factory envelopes, all synced:

#	Name	What it does
1	RAMP UP	rises over four steps and stays
2	RAMP DOWN	falls over four steps
3	BLIP	up at once, down in half a step
4	SWELL	in and out over four steps
5	DOUBLE	two blips half a step apart
6	STAIRS	four stairs, a step each
7	TRIANGLE	a two-step cycle, looping
8	S CURVE	slow, quick, slow, over four steps
9	DROP	holds a step, then falls
10	WOBBLE	a quarter-step flutter, looping
11	BUILD	eight steps up, then chains to 12
12	FALL	down in a step (BUILD's ending)

13 to 32 start empty. Projects made before this version get the twelve factory envelopes, and their steps' old library numbers are cleared (the old library swapped a step's volume envelope; set SE DEST to LEVEL for something like it).

8. LFO: modulation and macros

Page	KNOB 1	KNOB 2	KNOB 3	KNOB 4	PRESETS
MATRIX	SOURCE	TRACK (1–8, GLOBAL, or MATRIX: another row)	PARAM (with MATRIX: ROW 1–8, that row's AMOUNT)	AMOUNT (±)	slot 1–8
LFOS	L1 RATE	L1 SHAPE: SINE, TRI, RAMP, SAW, SQUARE, S&H, DRIFT	L2 RATE	L2 SHAPE	–
LFO SHAPE (OCT- / OCT+: LFO 1 or LFO 2)	SYM: skews the wave either way (± 64)	PHASE: where the wave starts, 0–359°	MODE: LOOP, RETRIG, 1 SHOT	–	–
DUST	RATE: how often random spikes happen, on average	DECAY: how long each spike lasts	SCATTER: how they fall. 0 random, like rain; up, spread out more and more evenly (+63: clockwork); down, in clumps, bursts of quick grains with long gaps between (−64: the most)	STRIKE: OWN, or DUST: strike tracks on the DUST or RAIN exciter take their grains from this source instead of their own RATE and ORDER (see below)	–
MACRO	DEST: what this slot moves	START value (±)	END value (±)	CURVE: LINEAR, EXP, LOG, S	which macro and slot
MACRO WINDOW	FROM %: where on the macro's travel this slot starts moving	TO %: where it stops	MACRO 1	MACRO 2	which macro and slot

• SYM moves the middle of the cycle from 5% to 95%, so each half of the wave speeds up or slows down: a sine leans, a triangle turns into a rising or falling ramp, a square becomes a narrow or wide pulse. The matrix can move it (target GLOBAL › L1 SYM or L2 SYM), so another LFO, dust or an envelope can reshape an LFO as it runs.
• A row can move another row: set TRACK to MATRIX and PARAM picks a row (ROW 1 AMT to ROW 8 AMT, any but its own). This row's source then moves that row's AMOUNT, by up to this row's AMOUNT either way, on top of what it is set to. For example, row 1 is LFO 1 into a cutoff at 0, and row 2 is MACRO 1 into ROW 1 AMT at +63: the macro fades the LFO's sweep in. Rows can chain (row 3 moving row 2 moving row 1). On the MATRIX picture a moved row's amount turns bone and its bar shows the amount as it is now.
• PHASE is where the cycle starts. In LOOP it offsets the wave; in RETRIG and 1 SHOT it is where a note restarts it.
• MODE: LOOP (the default) runs freely. RETRIG starts the cycle over on every note, on any track. 1 SHOT plays one cycle from each note, then rests at the cycle's end: an extra envelope.
• The LFOS and LFO SHAPE pages draw both waves as SYM and PHASE make them; on LFO SHAPE the one on the knobs is lit.

Matrix sources:

• LFO1, LFO2;
• DUST: random impulses, like crackle, shaped by SCATTER;
• ENV and VELO: the target track's own envelope and velocity;
• MACRO1–4;
• CLOCK: a pulse on every clock tick;
• KEY: the note the target track is playing, centred on C4. At AMOUNT +63 the parameter follows the keyboard exactly, one semitone per key (see below);
• WHEEL: MIDI CC 1 (the mod wheel) from MIDI in;
• TOUCH: aftertouch from MIDI in: channel pressure, or a keyboard's poly pressure (the latest key's). How hard you keep pressing a held key, for vibrato, a filter opening up, a swell;
• WEFT: a WEFT patch's MOD OUT block (the lowest track with one), anything you patch into it, from smoothed dust to a feedback network's wander;
• BEND: the pitch bend wheel from MIDI in, −1 to +1, centred at rest. Its AMOUNT is the bend's range in semitones: BEND › the track's PITCH at +2 bends a whole tone each way, +12 an octave (on CUTOFF it follows the keyboard's scale the same way; on other knobs, a step of the knob per unit). The matrix row names its track, so to bend several tracks, give each its own row.

The FM-1's own keys are switches: they play every note at the same velocity and have no pressure. VELO and TOUCH come alive with a MIDI keyboard that sends them (GLO › MIDI IN). For movement under your fingers on the FM-1 itself, map MACRO1–4 to the knobs you want and ride them, or record the knob moves.

Dust that plays. On LFO › DUST, turn STRIKE to DUST and every strike track on the DUST or RAIN exciter is struck by the DUST source's own grains, at its RATE and SCATTER, rather than by its own RATE and ORDER (which grey out). The same grains spike the matrix's DUST source and step a track clocked by DUST, so a body ringing, a filter jumping and a track stepping all happen together. A held note gets one grain as it starts, then only the source's. DUST's RATE tops out at about 50 grains a second; for denser rain, leave STRIKE at OWN.

The matrix: 8 slots, each "this source moves that parameter by this much".

1. Turn PRESETS to pick a slot.
2. Turn KNOB 1 to pick the source.
3. Turn KNOB 2 to pick the track.
4. Turn KNOB 3 to pick the parameter (only parameters that can move smoothly are offered).
5. Turn KNOB 4 to set the amount.

Key tracking with KEY. At AMOUNT +63, KEY moves these parameters by exactly one semitone a key: the INSERT TUNE of a COMB insert, CUTOFF, PITCH and FINE. Any other parameter moves one step a key. Smaller amounts track part of the way, and negative amounts turn the keyboard upside down. KEY reads the target track's newest note, so with several voices the comb follows the last key played.

Example: a strike track whose comb rings in tune with the keys.

1. On T5's INSERT page (EDIT), set INSERT to COMB. Leave TUNE at C4, its default. AMOUNT sets how strongly the comb rings (try 90–127), and MIX how much of it you hear (try 127).
2. Press LFO for the MATRIX page (not HOME › INFLUENCE: influence routes move a parameter by another track's envelope, not by the keys). Set SOURCE KEY, TRACK T5, PARAM TUNE, AMOUNT +63.
3. Play: the comb now rings in unison with every key. Turn TUNE to C5 for an octave above, or G4 for a fifth.

The comb reaches down to about F3; notes below that stop there.

Macros: 4 macros, each moving up to 8 destinations at once. Each destination has its own start and end values, curve, and window (FROM % / TO %).

• The window lets one knob turn do several things in sequence. For example, macro 1 from 0 to 50 % opens a filter, and from 50 to 100 % adds feedback.
• PRESETS walks through 32 slots: macro 1's eight destinations, then macro 2's, and so on.
• To play the macros, hold LFO and turn KNOB 1–4: they are macros 1–4 on any page.

9. FX: the buses

Each track can send part of its sound into three shared effects (buses): the delay, the space and the feedback loop. Their outputs go back into the mix.

How the sends work.

• On every FX page, one knob is called T1 SEND (or T2, T3…): that is how much of the current track goes into this bus.
• Turn ALGORITHM to set another track's send without leaving the page.
• The other knobs on the page set the bus itself, which is shared by every track.
• The same sends are also on EDIT › MIX and EDIT › SENDS.
• Every effect starts off. A new project's sends are all 0 and MASTER DRIVE is 0. Picking a sound with PRESETS leaves the track's sends where you had them, so no effect starts running because of a preset. The demos are the exception: they come with their own sends. A bus with nothing sent into it stops running once its tail has died away, so it costs nothing.

Page	KNOB 1	KNOB 2	KNOB 3	KNOB 4
DELAY	T SEND	TIME: free below the middle (10 ms to 0.5 s), tempo-synced divisions above	FEEDBK	LEVEL
DELAY 2	TONE: darker or brighter repeats	SPREAD: stereo ping-pong width (and how widely grains scatter)	DOUBLE: double tracking, a second wavering copy close behind	FREEZE: ON holds the repeats forever
TAPE WEAR	WOW: a slow, drifting sway of the tape's speed	FLUTTER: a fast waver	SATURAT: the tape driven, warm then gritty	AGE: darker repeats, hiss, dropouts
GRAINS	GRAINS: how much of the delay is a grain cloud (0: none)	DENSITY: how often grains start	SIZE: each grain, 20 ms to 0.4 s	PITCH: ±24 semitones
SPACE	T SEND	DECAY: how long it rings	DAMP: darker tail	LEVEL
SPACE 2	MOTION: a little chorus in the tail	CRUNCH: the stored samples from 12 bits down to 8	LOW CUT: keeps the tail out of the bass	–
BED	LEVEL (0: off)	DENSITY: how often its dust falls	TONE: wood (left) to metal (right)	SHIMMER: the body an octave and two up, slowly beating
BED 2	DUCK: how far busy tracks hold it down	DECAY: how long the body rings	SPACE: how much of it goes into the space reverb	–
FEEDBACK	T SEND	TIME of the loop	REGEN: how much goes round again	LEVEL
FEEDBACK 2	PROCESS inside the loop: FILTER, COMB, SMEAR, SHIFT, FOLD, CRUSH	AMOUNT of the process	TUNE of the process	CUTOFF of the loop's filter
FEEDBACK 3	EDGE: a guard that keeps the loop from running away	RETURN: to the MASTER, or into a track (T1–T8)	BASE: a high pass in the loop, over the lower half of the range (20 Hz, off, to about 600 Hz)	WIDTH: a low pass over the upper half (20 kHz, off, down to about 650 Hz); with BASE, a band that narrows as they meet

The delay is a tape. One short loop of tape, written at half rate and 12 bits (about half a second), driven on the way in (SATURAT). The echoes read it at TIME while the tape's speed sways (WOW, slow and drifting) and wavers (FLUTTER, fast and shallow); each pass goes through TONE, the tape's AGE (darker, a little hiss, and now and then a dropout, more as it ages) and the saturation again, so the repeats wear down like an old tape echo's. DOUBLE adds two copies of what comes in, 18 and 27 ms behind and wavering apart: double tracking, one knob. GRAINS mixes in a cloud of up to eight grains read from the same tape around the echo (after Mutable Instruments' Beads, kept lofi): DENSITY, SIZE and PITCH shape them, WOW scatters them, SPREAD widens them, and the cloud feeds back into the tape with the echoes. FREEZE stops the tape recording, so the echoes and the cloud play what it holds: freeze a phrase, then turn GRAINS, SIZE and PITCH.

The buses follow the matrix and the macros. On LFO › MATRIX, TRACK = GLOBAL, the PARAM knob walks the settings that can be moved: the clock, the LFOs and dust, and each bus's main settings (delay time, feedback, tone, level, wow, grains; space decay, damp, level, motion; the feedback bus and its BASE and WIDTH; the BED; master drive and cut mix). The macros reach the same ones.

The space is 12-BIT, a bright, metallic plate in the manner of late-1980s rack reverbs such as the Alesis Quadraverb: combs and allpasses run at half rate and kept in 12 bits, with the output held step by step, so the tail lisps, grains and aliases as it fades. DECAY is how long it rings and CRUNCH takes the stored samples from 12 bits down to 8. DAMP darkens it and MOTION adds a little chorus in the combs. (The FM-1 build keeps this one space; ROOM and CLOUDS, the filter pair, BANDS and the vocoder are in Ravel Software, the full version for the browser.)

The feedback bus is a delay loop with an effect inside. Each pass goes through the effect again, so a comb rises into a ringing pitch, a shift climbs or falls, and a fold grows harsher.

• Send it into a track (RETURN T1–T8) and the loop feeds back through that track's own filter and skin.
• If it gets too loud, turn down REGEN or turn EDGE on.
• BASE and WIDTH (FEEDBACK 3) are a band filter inside the loop, no resonance: BASE raises a high pass from the bottom, WIDTH lowers a low pass from the top, and turned all the way they nearly meet near 600 Hz, so each pass keeps only a narrow band. At BASE 0 and WIDTH full the loop is open.

The BED is a quiet layer under everything: grains of dust, and a breath of soft noise, falling on a small body tuned to the scale's root (SCL › ROOT). At TONE's left the body is wood, its modes spread like a marimba bar's and short; at the right it is metal, its modes clustered and inharmonic, and it rings long. SHIMMER adds its two lowest modes an octave and two octaves up, beating slowly. DUCK lets the tracks hold it down, quickly when they play and slowly letting go, so the bed comes up in the gaps between hits. SPACE sends it into the space reverb: with a long DECAY it becomes a grainy floor under the clicks. The picture shows the body's modes, the shimmer, the dust as it falls and, with DUCK up, how far it is held down. The dust is random, as dust is; the bed plays no notes and changes nothing in the patterns.

Microcuts (MASTER page) are slivers of the master output, looped, reversed or stuttered. Trigger them from steps (SEQ › STEP SHAPE › CUT, with their own shape and size on STEP CUT) or with the FX punch-ins (their shape: MASTER 2 › C SHAPE).

Punch-in effects: hold FX and press white keys 1–8:

Key	1	2	3	4	5	6	7	8
Effect	LOOP (microcut)	REVERSE	STUTTER	FREEZE the delay	LOW PASS sweep	HIGH PASS sweep	THROW: everything into delay and space	FILL: steps set to FILL play

The effects last while the key is held. Letting go of FX releases them all.

10. SCL: scale

KNOB 1	KNOB 2	KNOB 3	KNOB 4
ROOT: C to B	SCALE: CHROMA (off), MAJOR, MINOR, DORIAN, PHRYG, LYDIAN, MIXO, PENTA, MINPENT, WHOLE, HIRAJO, IWATO	TRANSPS: transposes everything that plays from steps (±24)	INTERVAL: this track plays only notes this many semitones apart from the root (1–12)

• The keys fold into the scale (like Elektron's fold mode). With a scale set, every key plays: the lowest key plays the first scale note at or above F, and each key after it plays the next note of the scale, so the keyboard runs up through the scale across several octaves and no key is wrong or dead. With CHROMA the keys are chromatic again. Notes you record from the keys are recorded as played.
• The sequencer snaps each step's note to the nearest scale note (a note exactly between two goes down).
• INTERVAL (per track): a track with interval N only plays notes that are a multiple of N semitones from the root; other notes are skipped. INTERVAL 1 plays everything, 12 only the roots, 7 the root and the notes a fifth apart (stacked fifths: the fifth, the ninth…), 2 every other semitone. Give two tracks the same notes with different intervals and they split them between them.
• Set the root from the keys: hold SCL and press a key.

11. ARP: the arpeggiator

ARP opens the arpeggiator of the current track. Each track has its own, off until you turn ARP (KNOB 1) away from OFF. Then every note the track gets (the keys you hold, its own steps, an influence's TRIG) is held instead of played, and the arpeggiator plays the held notes one at a time on the master clock, whether the transport runs or not. Let go of the keys and it stops.

Page	KNOB 1	KNOB 2	KNOB 3	KNOB 4
ARP	ARP: OFF, UP, DOWN, UP-DN, DN-UP (both turn at the ends without playing the end twice), PLAYED (the order the keys came), RANDOM	RATE: 1/4 (a beat), 1/8, 1/8T (triplets), 1/16 (a step), 1/16T, 1/32	OCTAVES: 1–4, the notes again an octave up each round	HOLD: the notes stay after the keys let go, until you play a new chord (see below)
ARP 2	GATE: 5–100 % of its step (100: each note runs into the next, legato, so a mono synth with GLIDE slides)	REPEAT: each note 1–4 times	CHANCE: 0–100 % that a step plays (else a rest)	–

HOLD works with the arpeggiator off too. Then it is a sustain for the keys: the notes you play keep sounding after you let go, until the first key of your next chord (which then sounds on in their place), or until you turn HOLD off. Switching HOLD on while you're already holding a note or chord holds that too: let go and it keeps sounding. It holds what you play on the keys (or a MIDI keyboard), not the track's steps.

The picture shows the notes it holds, in the order they came, and one round of the pattern they make: a column a step, as high as its note, the step it just played lit.

• With the sequencer: a step's chord (X2 to X4) or overlapping notes arpeggiate for as long as they last; when the transport starts, the arpeggiator lines up with the bar.
• Recording: with REC armed, what you play is recorded as you play it (the chord, not the arpeggio), so the arpeggio comes back the same on playback.
• A kit has no arpeggiator (its keys are lanes); a single PERC drum does.

12. SEQ: steps and the graph

Every track has its own sequencer, with two patterns (A and B) of up to 64 steps.

• PRESETS switches pattern while on SEQ pages, and so do black keys 1 and 2.
• Black key 9 (COPY) picks the current pattern as the source. Black key 10 (PASTE) copies that pattern, as it is at that moment and with a kit's locks, into the current one: switch to the other pattern, or to another track, first. A kit's pattern pastes only into a kit, and a note pattern only into a note track. Pasting over steps asks first: press it twice. The pattern's steps are copied; the track's LENGTH and RATE stay the target's own.
• Black key 11 clears the pattern: press it twice (the first press asks).
• A pattern launched while playing waits for the current one to finish (its LENGTH, at its RATE), then starts from its first step, so patterns of any length change cleanly. (A GRAPH track has no end, so it changes on the next bar.) Scenes change on the next bar.

The step keys

While you are on any SEQ page, or while you hold SEQ on any other page, the 16 white keys are steps.

Action	Result
Tap a key	The step toggles on/off
Hold a key, turn a knob	Edits that step's value (on STEPS, STEP TIMING, STEP SHAPE, GRAPH)
Hold a key, turn a knob on a non-SEQ page (with SEQ held)	A parameter lock: that step plays with that value (cutoff, drive, a source value…). Up to two locks per step.
OCT− / OCT+	Step page 1–16, 17–32, 33–48, 49–64

Editing a held empty step switches it on.

Page	KNOB 1	KNOB 2	KNOB 3	KNOB 4
STEPS	NOTE	VELO	LENGTH: how long the note holds, in eighths of a step to 16 steps ("7 1/2"), then in half steps up to 64 steps	CHANCE: 0–100 % that it plays
TEMPO (right after STEPS; on a kit, after DRUM)	TEMPO (30–240): the master clock's, the same value as GLO › CLOCK, so turning either moves both	SWING (shared with GLO › CLOCK too)	LENGTH: the track's (as on TRACK)	RATE: the track's (as on TRACK)
STEP TIMING	MICRO: nudge −6 to +12 (in 24ths of a step)	RATCHET: 1–8 repeats within the step	R CURVE: EVEN, FASTER, SLOWER, BOUNCE (see below); "-F" versions fade out	CONDITN, see below
STEP SHAPE	ENV: the LIBRARY envelope this step starts (– = none; see ENV › STEP ENV)	CUT: NONE, LOOP, REVERSE, STUTTER (a master microcut on this step)	TIE: ON holds the note until the track's next note starts	R MOVE: what each repeat of a ratchet does (see below)
STEP CUT	CUT (as on STEP SHAPE)	C SHAPE: EVEN, BOUNCE, DRAG	C SIZE: MASTER (the MASTER page's CUT SIZE), or 1/32 to 1/2 of a step	–
TRACK	MODE: STEPS or GRAPH	LENGTH: 1–64	RATE: ¼× to 4× the master clock	CLOCK: MASTER, LFO1, LFO2, DUST, WEFT (a WEFT patch's CLK OUT)
DIRECTION (steps mode)	FWD, REV, PINGPONG, SNAKE (rows of four, walked back and forth)	STEP REC: NEXT (step recording moves on after each note) or STAY (it stays on the step: note input, see Recording). Kept through power-off	–	–
EUCLID (the last SEQ page)	HITS	ROTATE	LENGTH (the track's)	–

STEP: PRESETS picks the step. On the step pages (STEPS, STEP TIMING, STEP SHAPE, STEP CUT; DRUM STEP on a kit), turn PRESETS to move through the steps, 1 to LENGTH: the knobs edit that step (ringed on screen, STEP 23 at the bottom right), and the keys jump to its 16. Holding a step key still works as before, and the black keys 1 and 2 still switch patterns A and B.

EUCLID spreads HITS as evenly as they go over the track's LENGTH (5 over 16 is x..x..x..x..x...., the first on step 1) and ROTATE turns the pattern round. It writes ordinary steps as you turn: the steps it lights are steps like any others, with their notes, locks and ratchets, and you can edit them by hand from there. HITS starts from how many steps play now. Each turn rewrites which steps play (up to LENGTH), so turn it to find a rhythm, then leave it. On a kit the page is LANE, HITS, ROTATE and the lane's LENGTH, and it writes the chosen lane only: give each lane its own length and hits for rhythms that interlock and drift. The picture is the pattern as a ring, E(hits, length) in the middle.

Ratchets that move. A ratchet repeats the step's note within the step. Two settings change how the repeats fall and sound:

• R CURVE BOUNCE spaces the repeats like a ball dropped on a table: the gaps shrink and each repeat is softer than the last. (EVEN, FASTER and SLOWER place them evenly, closing up or opening out; their "-F" versions fade.)
• R MOVE changes each repeat: UP and DOWN climb or fall a step of the scale per repeat (on a kit lane, two semitones); DARK closes each repeat down, darker, quieter and shorter than the one before, so a metal hit turns to wood as it rolls.

Together they give the bouncing, tumbling bursts of IDM: a hat on RATCHET 6, BOUNCE, DARK falls like a coin; a snare on 4, FASTER, UP rises into the next bar. On a kit, R CURVE and R MOVE are on STEP TIMING (KNOB 2 and KNOB 4) and act on the lanes that roll on that step.

Cuts with a shape. A step's CUT is a microcut of the whole mix (see FX › MASTER). On STEP CUT:

• C SHAPE EVEN repeats the sliver as it is; BOUNCE makes each repeat shorter and a little higher, like a ball settling (it adds a few repeats to settle in); DRAG plays each slower and lower, a tape winding down.
• C SIZE sets the sliver against the step, from 1/32 to 1/2 of a step (at most 93 ms), so it follows the tempo; MASTER uses CUT SIZE.

While a cut plays its sliver is held, so every repeat is of the same moment.

Conditions (CONDITN) decide on which passes through the pattern a step plays:

• ALWAYS;
• FIRST (only the first time) and NOT 1ST;
• 1:2, 2:2 (first or second of every two passes);
• 1:3 … 3:3;
• 1:4 … 4:4;
• FILL (only while the FILL punch-in is held) and NO FILL.

CLOCK lets a track step by something other than the master clock:

• LFO1/LFO2 step on each LFO cycle;
• DUST steps at random;
• an influence CLOCK route steps on another track's notes.

All of these give rhythms that drift against the grid.

On the STEPS picture:

• the top strip is the whole pattern, with the playing step bright;
• the grid is the current page of 16;
• each box shows the note and a velocity bar;
• outlined boxes are where the playheads are.

GRAPH mode (Silt's sequencer)

Set SEQ › TRACK › MODE to GRAPH. Now the steps sit in a circle, and each step has cords that say where a playhead goes next, instead of always moving to the following step. The pages after TRACK change to GRAPH, HEAD 1, HEAD 1 MOTION (and HEAD 2, HEAD 2 MOTION when head 2 is on).

GRAPH drives the same steps. It is not a second sequencer: the steps you set on the STEPS pages (which are on, their notes, velocity, length, locks, ratchets and the rest) are exactly what plays in GRAPH mode too. GRAPH only changes the order the playhead visits them, and adds a second playhead. Edit the steps on STEPS, STEP TIMING and STEP SHAPE in either mode; draw the cords on GRAPH.

Page	KNOB 1	KNOB 2	KNOB 3	KNOB 4	PRESETS
GRAPH	CORD A: the step to go to next, 1 to LENGTH (NEXT = just the following step)	CORD B: a second choice (NONE = no branch)	BRANCH: how to choose between A and B	HEAD 2: OFF, NOTES, RHYTHM, MELODY	step to edit
HEAD 1	TRANSP: head 1's transpose	–	–	–	–
HEAD 1 MOTION	SHAPE	DEPTH (±)	CYCLE: 2–64 steps	COMBINE: × CLOCK or + CLOCK	–
HEAD 2	PLAYS: THIS track, or T1–T8	H2 RATE	H2 START: the step it starts on (1 to LENGTH)	TRANSP	step
HEAD 2 MOTION	SHAPE	DEPTH	CYCLE	COMBINE	–

Making a graph:

1. Go to the GRAPH page.
2. Pick a step with PRESETS, or hold its white key. With more than 16 steps (TRACK › LENGTH), the white keys hold 16 at a time: OCT+ and OCT− move them to steps 17–32, 33–48 and 49–64 (and put that page's first step on the knobs). The steps on the keys turn slate on the circle, the step on the knobs keeps its colour with a slate edge, the footer says which steps the keys hold (KEYS: 17-32), and the step on the knobs is named (STEP 17).
3. Set CORD A (where it goes) and, if you want a branch, CORD B. The cords are drawn on the circle. A cord can only point at a step that exists (1 to the track's LENGTH). If you shorten LENGTH later, cords to steps past the end are ignored: they read NEXT or NONE until LENGTH grows again.
4. Choose BRANCH, which decides between A and B at a fork:
   • CHANCE: a coin toss;
   • TURNS: alternate each visit;
   • LFO1/LFO2: by the LFO's sign;
   • MOTION: by the head's function generator (above half way takes B).

Two playheads walk the same graph at once.

• Head 1 plays this track.
• Head 2 is off until you choose what it does with HEAD 2 on the GRAPH page. It has its own rate and start step, and can play another track (HEAD 2 › PLAYS).

HEAD 2 chooses how the two heads share the work. Head 1 always takes the other half, so no setting leaves the track silent:

HEAD 2	Head 2	Head 1
OFF	–	plays the steps it visits
NOTES	plays the steps it visits too: two voices on one graph	plays the steps it visits
MELODY	picks the notes, plays nothing itself	plays the rhythm, with head 2's latest note
RHYTHM	plays the rhythm, with head 1's latest note	picks the notes, plays nothing itself

With MELODY or RHYTHM, rhythm and melody walk two different paths at two different speeds, so they never quite line up the same way twice. The picture shows each head's job at the top (H1 and H2).

MOTION (Silt's function generators) moves a head's speed as it travels.

• SHAPE:
  • RISE, FALL, ARCH, DECAY or SWELL, traced once every CYCLE steps;
  • or LFO 1, LFO 2 or DUST, followed live.
• DEPTH sets how far it pushes; negative reverses the effect.
• COMBINE sets how it meets the clock:
  • × CLOCK multiplies or divides the clock (up to two octaves faster or slower), so it accelerates and decelerates musically;
  • + CLOCK adds to the clock's rate (from slowing to a near halt up to racing).
• The MOTION picture draws the shape, where the head is on it, and its current speed in steps per pulse.

13. GLO: song, scenes and clock

Page	KNOB 1	KNOB 2	KNOB 3	KNOB 4	PRESETS
MIXER 1-4	T1 LEVEL	T2 LEVEL	T3 LEVEL	T4 LEVEL	–
MIXER 5-8	T5 LEVEL	T6 LEVEL	T7 LEVEL	T8 LEVEL	–
MUTE / SOLO	– (the keys, below)				–
CLOCK	TEMPO (30–240)	SWING: 50 % is straight, 66 % a triplet shuffle, up to 100 % (every second 16th pushed late)	B DOES: how oscillator B bends the clock	DEPTH of that bending	–
CLOCK B	A SHAPE: the main clock's wave	B RATE	B SHAPE	THRESH: where a pulse fires	–
CLOCK FEEL	TEMPO IS: LOCKED (keeps the average tempo) or FREE (drifts)	QUANTZE: pulls microtiming back to the grid (0–100 %)	METRO: the metronome, OFF, QUIET or LOUD (a click on each beat, higher on the bar's first)	COUNT-IN: OFF, 1 BAR (the default) or 2 BARS	–
MIDI IN	MIDI CH: OMNI (any channel plays the current track), 1–16 (only that one), or MULTI (channels 1–8 play T1–T8, for a sequencer driving every track)	CLOCK IN: RAVEL (its own clock) or MIDI (24 clocks a beat from USB or the TRS jack; the picture shows the tempo measured, or that none is coming)	START/STP: FOLLOW (MIDI Start and Continue start the transport, Stop stops it) or IGNORE	–	–
MIDI LEARN	LEARN: turn it right to arm, then turn any knob on any page, then move a control on your controller	DELETE: turn twice to delete the one PRESETS picked	CLEAR ALL: turn twice	–	which learned control
SCENES	PLAYS: PATTERN (you launch) or SONG (the arrangement runs)	S1 TEMPO … S16 TEMPO: the tempo the current scene sets when it launches, or KEEP (turn fully left) to leave the tempo alone	TEMPO: the tempo now	GLIDE: JUMP, or 1–8 bars (see below)	scene
ARRANGE	SCENE for this row, or END (past 16): the song stops when it gets there

CPU: where the audio's time goes. The bars show how much of the time the audio has each part of the render takes: CONTROL (the sequencer, modulation, the knobs), SYNTH, STRIKE, PERC, WEFT, TRACK FX, BED, FEEDBACK, DELAY, SPACE and MASTER. A bar's full length is 50 %. RENDER is the total on the first core (the one that must keep up); past about 90 % the FM-1 falls behind. VIEW TRACKS shows each track instead: what its voices and its own effects cost (the voices' share is the time they last took, on whichever core played them; the buses and the master are shared, shown below the tracks, and in no track's bar). A track whose voices SKIP SILENT has stopped reads SKIP. PEAK is the busiest single audio block lately (all of it, the screen's share included): when it nears 100 %, that block was nearly late. CORE 2 is the second core's share: the effects and the voices it plays (a part's bar counts its time on whichever core runs it); WAIT is how much of the first core's time went on waiting for it. XRUNS counts the blocks that came too late: each one is a crackle, and a steady stream of them is the loud noise an overloaded FM-1 makes. Measured on the FM-1 and the desktop simulator; the browser has no clock for it.

The overload guard. When the render takes more than 80 % of the time it has, the guard fades out a voice over about 3 ms: a released one first, then a note of the track with the most voices sounding (a chord loses a note before a lone line goes quiet), then the oldest; more than one at once when the load is far over. Its reading rises at once and falls slowly, so a chord landing on the last one's release is met in the block it comes. It then holds the voice count there (a new note past the limit makes room the same way) until the load has stayed under 76 % for a moment, and lets it back up a voice at a time. The CPU page shows it (GUARD: 6 VOICES, and how many it has faded). It never acts in the browser.

When fewer voices are not enough (the guard is down to two voices, or the voices are not what costs: a big WEFT patch, the GRAINS, the effects), the guard eases the rest a step at a time rather than fall behind into noise, and shows it (EASED 1–3):

Step	What eases
EASED 1	the delay's GRAINS: half as many new grains, six at most at once
EASED 2	a quarter as many grains, four at most; WEFT new notes take one voice
EASED 3	two grains at most; the guard may go down to one voice

Grains already playing finish as they were, and sounding WEFT voices play on: nothing is cut off, the texture just thins while the FM-1 is overloaded. Once the load has stayed under 76 % for about a quarter second it steps back, one step at a time, and then gives the voices back. If EASED stays up, the patch is more than the FM-1 can play: lower the GRAINS mix or density, the sends, or the WEFT patch's size.

SKIP SILENT. A track you can't hear (muted, or its LEVEL at 0) still costs its voices. With SILENT on SKIP (the default), once a track has been unheard for half a second, its voices stop and new notes on it play nothing; as soon as you unmute it or raise its level, its next notes play as ever (a note held across the unmute does not come back: play it again). It is skipped only when nothing else uses its sound: not when an influence route goes from it, the GLITCH LOOPER records it, the COMP's SIDECHAIN listens to it, its WEFT patch has an output (CLK, MOD or SEQ OUT, or RUN ALWAYS), or (T1) its envelope moves a global knob in the matrix. VIEW TRACKS shows which tracks are skipped. SILENT PLAY keeps every voice playing, as before; it is not saved with the project.

Two cores. The FM-1's chip has two cores, and Ravel starts the second at power-on. It runs the effect buses (the BED, FEEDBACK, DELAY and SPACE), and it takes a share of the sounding voices (synth, strike, drum or WEFT), while the first core plays the rest and every track's chain. The voices are shared out by what each one cost a moment ago, the dearest first, so that both cores finish at the same time: a heavy WEFT patch goes to whichever core has room, and when the effects are heavy the second core takes fewer voices. The CPU page shows its share (CORE 2 40 %), and WAIT how long the first core waited for it. For this the buses play one control step behind the tracks: the effects come about 3 ms after the dry sound, with one core or two, so the sound is the same either way. On some units the second core misreads memory, so it is watched: if it ever reads a wrong job or doesn't finish one in time, the first core takes the work back at once (CORE 2 FAILED on the CPU page), and after a crash or a hang with it running it stays off until the FM-1 is switched off and on (the top bar says ONE CORE: POWER OFF AND ON FOR TWO at start, and CORES reads 1). Installing an update is not counted: the second core comes back on its own afterwards. CORES 1 turns it off by hand.

MIDI control of the knobs. Two ways, and both follow MIDI IN's channel:

• CC 70–73: the knobs on screen. On any page, CC 70 turns KNOB 1, 71 KNOB 2, 72 KNOB 3 and 73 KNOB 4, whatever they are on that page (a sound's knobs on EDIT, a step's while one is held, the mixer on GLO). Any controller with four knobs set to send 70–73 plays the whole instrument, page by page.
• MIDI LEARN: one control, one parameter. On GLO › MIDI LEARN, turn KNOB 1 (LEARN) right; the footer says LEARN: TURN A KNOB. Go to any page and turn the knob you want (a track's or a global one, such as T3's CUTOFF or the delay's FEEDBACK); the footer says LEARN: MOVE A CONTROL. Move the control on your controller: it's tied ("CC 21 CH1 > T3 CUTOFF") and moves that parameter from then on, wherever you are. Up to 16; the page lists them. PRESETS picks one, KNOB 2 (DELETE) turned twice deletes it, KNOB 3 (CLEAR ALL) turned twice clears them all. Learning a control that's tied already moves it to the new parameter; a learned control wins over 70–73.
• Pickup. A control only takes hold once it reaches the value the parameter already has (or passes it), so changing page, project or sound never makes a value jump. Turn it through the value shown and it follows.
• The learned controls, like MIDI IN's settings and the backlight, belong to the FM-1, not to a project: they stay through power-off and whatever you load.

PANEL. The FM-1's buttons and keys glow dimly, so you can find them in the dark; what's lit (the page's button, a step, a key held) stays lit fully, so the two never get mixed up. BACKLIGHT sets how dim: OFF, LOW, MID or HIGH. The glow comes from the panel's own scanning (each unlit LED is lit on one scan in a few), so it costs the sound nothing and the keys are read as before. It's kept through power-off.

FLASH. The page after STRESS shows how the FM-1's boot set its flash up: the chip, its status (QE: whether its four-wire mode is allowed), the flash controller's read mode and clock divider. It is read once at start and nothing on it writes the flash. A photo of it tells whether a faster read is possible on that unit.

FLASH WAIT. The FM-1 runs Ravel's code straight from its flash memory, through a cache. When the code the render needs is not in the cache, the core waits for the flash. FLASH WT ON counts those waits and shows them as a share of the render (FLASH WAIT 30 %). The busiest audio code already runs from the chip's RAM (the delay, the space, the feedback loop, the BED, every synth voice's filter and amplifier, the VA oscillator, the master's limiter, the modulation step, the voices' envelopes and their hand-off between the cores, and, in the RAM the tape left free, every synth engine, the strike voices and the 33 drum machines); a high number says more of it should. The counters are not verified on hardware yet, so it is off by default.

STRESS: how much this FM-1 takes. The stress test replaces the project in memory (save yours first; it asks twice), builds a project that adds load a step at a time, and plays it, with the overload guard off so you see the real edge:

Step	Adds	Step	Adds
1	nothing (the idle cost)	9	every track into the DELAY
2	1 voice of ENGINE, held	10	the delay's GRAINS, busy
3	2 voices	11	TAPE WEAR: wow, flutter, age
4	4 voices	12	every track into the SPACE
5	8 voices	13	the FEEDBACK bus
6	2 strike voices, hit on every other step	14	the feedback's PROCESS (a frequency shift) and its band
7	a drum kit, a hit on every step	15	the BED, with SHIMMER and a send to the space
8	a second drum kit, a hit on every step	16	MASTER DRIVE

Each step is measured from its first second to its third; the table shows the RENDER % for each step (and the second core's after a /, when it works), red with a ! where XRUNS started. Each effect step's rise over the one before is what that effect costs. AUTO RUN walks all sixteen in under a minute and leaves the table on screen: a photo of it says exactly what this FM-1 can do. Change ENGINE to compare engines (STEP 5 is 8 voices of it). Turn STEP to OFF to stop. Loading any project or demo ends the test.

MIDI in. Notes from a keyboard or a sequencer, over USB or the TRS jack, play a track as its keys do, and are recorded when it is armed (with their timing, as the keys are). Velocity comes through as played. CC 1 is the matrix's WHEEL, aftertouch (channel or poly pressure) its TOUCH and pitch bend its BEND; CC 120 and 123 stop every note. With CLOCK IN at MIDI, Ravel follows the incoming clock (every 6th of its 24 a beat is a step) and its own TEMPO waits; Start starts from the top. Steps are counted from the clocks themselves, so Ravel never drifts from the sender, however long it runs. On the FM-1 each clock is timed as it comes in, and its step lands one audio block (2.9 ms) later at the same spacing, so the steps keep the sender's timing rather than snapping to the blocks. MIDI notes step-record too (below). Controllers: CC 70, 71, 72 and 73 always move KNOB 1–4 of the page on screen, as if you turned them, with nothing to set up; and GLO › MIDI LEARN ties any control to one parameter, wherever you are (below). The MIDI IN settings belong to the FM-1, not to a project: they stay as you set them through power-off and whatever project you load (on the FM-1 they are written to the flash a second after a change, or as soon as you leave the page, playing or not, which can leave a moment's gap in the sound once; the page's last line says KEPT THROUGH POWER-OFF when they are). In the emulator, Listen to MIDI (left panel) takes every MIDI input on the computer.

Metronome and count-in. METRO clicks while the sequencer plays; the click goes straight to the output and is never recorded. With REC armed, PLAY first counts in (the clicks sound even with METRO off, and the screen shows COUNT-IN with the beats left), then starts at step 1. Notes played during the count-in are not recorded, except one played just before step 1, which lands on it. Without REC, PLAY starts at once.

Scenes are snapshots of every track's pattern (A/B), levels, influence routes, mutes and macros.

• Store: hold SAVE and press a white key (1–16). Over a stored scene, the first press asks: press again to overwrite.
• Launch: on the SCENES page, press a white key. It changes on the next bar. Black keys 1–2 there switch the current track's pattern.
• Glide: with GLIDE set to 1–8 bars, a launched scene (or an arrangement row) changes its patterns and mutes on the bar as before, but the track levels, the macros and the influence routes' amounts travel to the scene's over that many bars, easing in and out. A route the new scene adds grows from nothing; a route it drops fades, then goes. GLIDE JUMP switches everything at once, as before. Stopping mid-glide lands on the scene.

Arrangement: a list of up to 32 rows, each "play scene S for B bars".

1. Set ROWS to the number of rows the song needs.
2. Pick each row with PRESETS and set its SCENE and BARS.
3. Set PLAYS to SONG and press PLAY.

Without an END row the song loops back to row 1. Give the last row the scene END to have the transport stop there. A scene with its own tempo (S TEMPO) changes the tempo when its row starts.

Density arcs. For each track, draw 16 points of density, each lasting SPAN bars (1, 2 or 4: an arc of 16, 32 or 64 bars, so a part can stay quiet for a long stretch and open up once).

• At 100 % every step plays. Lower values thin the part out, off-beats first and downbeats last.
• One pattern can then breathe across a phrase without writing new patterns.
• Pick the bar with PRESETS and the track with ALGORITHM.

The clock (after Silt's two-oscillator clock).

• Oscillator A is the tempo. B DOES lets a second, slower oscillator bend it:

  B DOES	Effect
  STEADY	No bending
  RATE	Speeds up and slows down
  SHAPE	Changes the swing-like shape
  PHASE	Pushes and pulls the pulses
  SUM	Adds the waves
  AND, OR, XOR	Logic rhythms between the two

• With DEPTH at 0 the clock is straight.

• TEMPO IS: FREE lets it drift like an old drum machine.

• Tap tempo: hold GLO and tap black key 1.

• Mute and solo: hold GLO and press white keys 1–8 to mute tracks 1–8, or 9–16 to solo tracks 1–8. From any page.

• The MUTE / SOLO page (GLO, after the mixers) lays the eight tracks out for bringing parts in and out by hand, no button held: white keys 1–8 mute and unmute tracks 1–8, and 9–16 solo them (or hold GLO and press 1–8). Black key 1 unmutes every track, black key 2 ends the solo. Each track's tile and its key light while you hear it; a muted track's tile goes dark with MUTE in red and its key goes out, and while anything is soloed the tracks left out go dark too (the soloed ones are outlined, and keys 9–16 light for them). Mutes and solos change at once; scenes store and recall the mutes as before.

14. SAVE: projects and sounds

SAVE has two pages: PROJECT (the whole song) and SOUNDS (one track's sound at a time). Turn SELECT to go from one to the other.

Projects

1. Press SAVE to open the page.

2. Turn PRESETS to choose a slot (1–32). The picture shows eight at a time around the chosen one, which are used and their names, and on the FM-1 how much room the projects have left (ROOM).

3. Turn KNOB 1 (ACTION):

   Action	What it does
   SAVE	Saves the project to the slot
   LOAD	Loads the slot
   DEMO 1	The Ravel demo
   DEMO 2	Dust
   DEMO 3	The graph demo
   INIT	A new, blank project
   CLEAR	Empties the slot, so it shows EMPTY and its room is free again (the project you have open stays as it is)

4. To name the project, use KNOB 2 (CURSOR) to pick a letter's place (1–11) and KNOB 3 (LETTER) to choose it (A–Z, 0–9, space and - + # & ' .), as on SOUNDS. The name shows on the right, with a mark under the letter on the cursor. It belongs to the project you are working on, so name it before you SAVE; LOAD brings back the name it was saved with.

5. Press SAVE once: the footer says "PRESS SAVE AGAIN TO CONFIRM".

6. Press SAVE again to do it.

Ravel starts on a blank project every time it is switched on (or the emulator is opened). Saved projects stay in their slots: load one with LOAD.

There are 32 project slots. On the FM-1 a project is kept compressed (most fit in one 4 KB block of the flash, a very busy one in a few), so they share the room: ROOM on the page says how much is left, and if a save doesn't fit, it says NO ROOM: SAVE OVER ANOTHER and nothing is lost. Projects saved in slots 1–7 by an earlier version are still there; the first save after updating compresses them too, which takes a second or two once.

A project holds everything: all eight tracks and their patterns, influence, modulation, buses, scenes, the arrangement, arcs and the LIBRARY of step envelopes. A project saved before the tape was removed still loads: its tape tracks come back as blank VA synths with empty patterns, and influence TAPE routes are switched off.

Sounds: your own bank

Four banks (A–D) of 32 slots for your own sounds, 128 in all, of any kind: a synth on any engine, a strike, a perc machine or a whole kit. Each has a name, and its kind is shown on the right of the list (SYNTH, STRIKE, PERC, KIT; a synth also shows its engine). The banks are shared by every project and stay when you load another project or switch off.

A sound is the track's voice: its kind and engine, every sound setting (source, filter, skin, envelopes, insert, sends, the CZ patch, a kit's lanes). It is not the track's steps, sequencer settings or pan.

1. Press SAVE, then turn SELECT to SOUNDS.

2. Turn KNOB 4 (BANK) to a bank, then PRESETS to a slot. Slots are named by bank and number (A1 … D32), and PRESETS runs on from one bank into the next (A32, then B1).

3. Turn KNOB 1 (ACTION):

   Action	What pressing SAVE does
   LOAD	Puts the sound on the current track. A sound of another kind turns the track into that kind (a PERC sound on a synth track makes it a perc track).
   SAVE	Keeps the current track's sound in the slot. An empty slot saves at once, named after the factory preset it came from (or its engine and slot, like VA B3). Over a used slot, press SAVE twice; the slot keeps its name.
   CLEAR	Empties the slot (press SAVE twice)

4. Name it: on a used slot, KNOB 2 (CURSOR) picks a letter position (1–11) and KNOB 3 (LETTER) changes the letter (A–Z, 0–9, space and - + # & ' .). The cursor is the amber line under the name. The name is kept a moment after you stop turning.

Loading a sound that changes a track between a kit and notes (lanes and notes don't read each other's steps) clears that track's steps, so it asks first: press SAVE again.

From PRESETS: on any EDIT page, turning PRESETS walks the factory sounds of the track's kind and then your own of that kind, from the bank chosen here (knob 4): the footer and the top bar name each one (A3 MY BASS). So a sound you keep is a turn of PRESETS away on any track.

In the emulator, your sounds are at the top of the sound menu under My sounds, one group per bank, each with its slot (A1 … D32) before the name and its kind in brackets after it. Choosing one loads it into the current track, switching its kind if needed. Save sound… keeps the current track's sound (it asks for a slot such as B5, offering the first empty one, and a name), and Delete sound… removes one. The panel's SAVE › SOUNDS page works too.

Moving projects and sounds to an FM-1 (and back)

Everything you have saved, the projects in slots 1–32 and the sound banks A–D, can leave the emulator as a file and go onto an FM-1 running Ravel, and the other way. The FM-1's own update leaves its saved projects and banks alone, so install the firmware first, then bring your work over.

In the emulator (the Projects & sounds panel on the left):

Button	What it does
Export file	Every saved project and sound bank, as one .ravel file to keep
Import file	A .ravel file into the emulator's slots (it asks before replacing used ones)
Send to FM-1	This page's saved projects and banks straight onto an FM-1 connected by USB with Ravel running (Chrome or Edge: allow MIDI when asked; it asks before replacing slots on the FM-1)
Get from FM-1	The FM-1's saved projects and banks, read into a .ravel file (Import file then brings them into the emulator)

From the command line (pip3 install mido python-rtmidi), with the FM-1 connected and Ravel running:

python3 tools/fm1_data.py info                      # what the FM-1 holds
python3 tools/fm1_data.py restore my-work.ravel     # the file's projects and banks onto the FM-1
python3 tools/fm1_data.py backup fm1-work.ravel     # the FM-1's, into a file
python3 tools/fm1_data.py restore my-work.ravel --only project3,bankB

Each project and bank goes to the same slot it came from (project 3 to project 3, bank B to bank B) and replaces what was there; slots not in the file are left as they are. Every piece is checked as it arrives (a CRC over the whole slot), and a slot only becomes valid on the FM-1 once all of it has arrived intact; the screen says RECEIVED PROJECT 3 or RECEIVED BANK B as each one lands. Load a project afterwards with SAVE › PROJECT › LOAD.

15. Hold layers

Hold a button (in the emulator: right-click or shift-click to latch it) and the keys or knobs do something else. The footer always shows the layer's hint.

Hold	Then	Does
SEQ	white keys	Steps, from any page. Hold a step and turn a knob to lock that value on that step.
SEQ + ENV	hold a step, turn KNOB 1	The step's LIBRARY envelope
LFO	KNOB 1–4	Macros 1–4
FX	white keys 1–8	Punch-ins: loop, reverse, stutter, freeze, low pass, high pass, throw, fill
GLO	white keys 1–8 / 9–16, black 1	Mute / solo, tap tempo
SAVE	white key	Store scene 1–16
SCL	any key	Set the root

16. Recording

1. Choose the track with ALGORITHM.
2. Tap REC. "RECORDING ARMED" flashes and a red dot appears in the footer.
3. Press PLAY.
4. Now, while it plays:
   • notes you play are written into the steps, with their timing kept as microtiming; chords too: keys pressed together land on one step as a chord of up to four notes (the step's note and up to three more), and play back together. A note played on a step while none of its keys is still down replaces what was there;
   • knobs you turn are written as parameter locks on the playing step;
5. Tap REC again to stop recording.

Turning ALGORITHM while armed moves recording to the new track.

Step recording. With the transport stopped, open a SEQ page and tap REC: the keys play notes, and a red cursor sits on the step after the last note (STEP REC 5 on the screen; its key blinks).

• Play a note, or hold a chord (up to four keys together): it goes on the cursor's step, replacing what was there (the step's locks and tricks stay). When you let go of the last key, the cursor moves to the next step.
• OCT+ leaves a rest (empties the step) and moves on. OCT− goes back a step, to play it again.
• PRESETS moves the cursor, a step a click, or hold SEQ and tap a step to put it there, for instance to change one chord in the middle of a pattern.
• Length as you go: on STEPS the knobs edit the cursor's step, so turn KNOB 3 (LENGTH), before or while you hold the keys: the notes take that length, and so do the ones after it until you change it. Letting go moves the cursor past the note, so a note two steps long moves it on two (and leaves the step between as it was).
• Hold REC and press OCT− or OCT+ to change the keys' octave.
• Note input (STAY): set SEQ › DIRECTION's STEP REC to STAY and the cursor stays where it is: PRESETS picks a step, and the keys play and write notes into it as often as you like (try a few, the last one stays), then PRESETS on to the next. NEXT (the default) moves on after each note. The setting belongs to the FM-1 and stays through power-off.
• Notes from a MIDI keyboard step-record too.
• Press PLAY to hear it: recording carries on live as usual. Stop, and step recording picks up after the last note. Tap REC to finish.

Step recording is for synth and strike tracks; a kit's keys stay its steps (tap them in).

TAKE: keep what you just played. While the transport runs and you're not recording, Ravel quietly listens to what you play on the track you're on (the keys or a MIDI keyboard), as recording would write it. If you played something you like, hold REC and tap SAVE: the last loop's worth of it (the track's LENGTH, back from now) goes into the pattern, chords, timing and lengths as played, over what's there; the screen says how many steps it kept. It works after you stop, too. Changing track starts it afresh.

Chords on steps. A step with a chord shows X2, X3 or X4 (how many notes) under its note on the STEPS page. NOTE moves the whole chord, its shape kept; transposition, the scale and INTERVAL apply to each note. The chord's notes share the step's velocity, length, ratchets and timing. To make a step a single note again, record one note over it. Chords need the voices: a synth track plays up to four notes at once (VOICES on EDIT › SOUND).

Recording from a SEQ page. On the SEQ pages the keys are normally the steps. With REC armed on a synth or strike track they play notes instead, so you can watch the steps fill in as you play (the footer says REC: KEYS PLAY); OCT- and OCT+ change the octave rather than the step page (while it plays; stopped, they are step recording's rest and back). Hold SEQ for the keys to be steps again for a moment: tap one to add or remove a step, then let go and keep playing. Tap REC to stop, and the keys are steps again. A kit keeps its keys as steps on SEQ pages; play its lanes from any other page.

17. Recipes, step by step

Make a first sound

1. Turn ALGORITHM to T1.
2. Press EDIT (SOUND page). Turn KNOB 2 to CZ.
3. Turn PRESETS to hear the CZ sounds (CZ BRASS, CZ BELL, CZ STRINGS…); play the keys.
4. Turn SELECT to DCW 1. Turn PRESETS to step 1 and turn KNOB 2 (LEVEL) up to make the attack brighter.
5. SELECT to DCA 1. On step 1, turn KNOB 1 (RATE) down for a slow swell.

Loop what's playing (the GLITCH LOOPER)

1. Press PLAY with something going. Turn ALGORITHM to a spare track (T8).
2. EDIT (SOUND page): turn KNOB 1 (KIND) to GLITCH. SELECT one page on to GLITCH LEVEL.
3. Tap black key 1: lane 1 records. After a bar, tap it again: it loops.
4. Mute the tracks you recorded (GLO › MUTE / SOLO) and play with GLITCH PITCH and GLITCH SPEED, or hold white keys 1–4 to play its quarters.
5. When you're done, GLITCH INPUT › LOOPER to OFF brings every effect back.

The full walkthrough is GLITCH LOOPER, step by step.

Write a beat

1. Turn ALGORITHM to T5 (strike).
2. Press SEQ. Tap white keys 1, 5, 9, 13. Press PLAY.
3. Hold key 13 and turn KNOB 2 (VELO) down for a softer hit.
4. SELECT to STEP TIMING. Hold key 9 and turn KNOB 2 (RATCHET) to 3 for a roll.
5. To lock a sound change on one step:
   1. Press EDIT, SELECT to SOURCE 1.
   2. Hold SEQ, hold key 5, turn KNOB 4 (TONE).
   3. Let go. Only step 5 is brighter.

Two-headed graph melody

1. ALGORITHM to T1. SEQ, switch some steps on with different NOTEs (hold a key, turn KNOB 1).
2. SELECT to TRACK, MODE = GRAPH.
3. GRAPH page: pick step 4 with PRESETS, set CORD A = 1 (it loops back), CORD B = 8 (or branches ahead), BRANCH = TURNS.
4. HEAD 1: ROLE = GATE, HEAD 2 = PITCH.
5. HEAD 2: H2 RATE = 2/3, H2 START = 5.
6. HEAD 1 MOTION: SHAPE = ARCH, DEPTH = +32, CYCLE = 16. The rhythm speeds up and slows down over 16 steps while the melody walks its own path.

Put reverb on just one track

1. ALGORITHM to the track. Press FX, SELECT to SPACE.
2. KNOB 4 (T3 SEND, for example) up. The other tracks' sends stay where they were.
3. SPACE 2: raise MOTION for a moving tail and LOW CUT to keep it out of the bass.

One track plays another

1. ALGORITHM to T5 (the source). Press HOME, SELECT to INFLUENCE.
2. PRESETS to column 2, T2 (the target). KNOB 1 = TRIG, KNOB 3 (DELAY) = 2, KNOB 4 (CHANCE) = 60.
3. Now 60 % of T5's hits also play T2 two steps later.

Save your work

1. SAVE, PRESETS to a slot, KNOB 1 = SAVE.
2. Press SAVE, then SAVE again.

Keep a sound and use it on another track

1. Pick the track with the sound. SAVE, SELECT to SOUNDS.
2. PRESETS to an empty slot, KNOB 1 = SAVE, press SAVE.
3. Name it with KNOB 2 (position) and KNOB 3 (letter).
4. ALGORITHM to another track, KNOB 1 = LOAD, press SAVE. The track becomes the sound's kind if it wasn't already.

18. Quick reference

I want to…	Press / turn
Pick a track	ALGORITHM (emulator: 1–8)
Next page	SELECT, or tap the section button again (FX: the next bus)
Change a sound	PRESETS on any EDIT page
Start / stop	PLAY (emulator: Space)
Turn steps on	SEQ, tap white keys
Edit one step	Hold its key, turn knobs
Lock a value on a step	Hold SEQ + step, turn a knob on any page
Pattern A / B	Black key 1 / 2 on SEQ, or PRESETS
Mute / solo	Hold GLO + white 1–8 / 9–16, or the MUTE / SOLO page: white 1–8 / 9–16
Tap tempo	Hold GLO + black 1
Change the tempo	SEQ › TEMPO (or GLO › CLOCK), KNOB 1
Arpeggiate a chord	ARP, KNOB 1 to UP (or another mode), hold the keys
Glue the whole mix	T8: HOME › TRACKS, KIND = COMP; EDIT › COMP
Loop what's playing	A spare track: EDIT › SOUND, KNOB 1 (KIND) = GLITCH; black key 1 to record lane 1, again to stop
Loop: play, slices, clear	Black 5–8 play lanes 1–4; hold white keys for slices; hold black 9 + black 1–4 clears a lane
Loop: sequence it	SEQ › GLITCH TRIGS: KNOB 2 = REC or PLAY, tap a step; hold a step + tap another for a section
Effects back from the looper	GLITCH INPUT, KNOB 4 (LOOPER) = OFF, or KIND back
Patch a voice from blocks	EDIT › SOUND, KIND = WEFT; WEFT PATCH: KNOB 1 block, 2 type, 3–4 input A; WEFT BLOCK: input B, settings
Load, save, delete WEFT patches	WEFT LIBRARY: KNOB 1 picks, black key 1 load, 2 save (into a new slot unless on one of yours), 3 delete, 4 INIT, 5 CLEAR (twice each); KNOB 3–4 rename
WEFT: input B moves a setting	WEFT BLOCK: black key 1
WEFT: a sequential switch	SW 1>4 (outs SW 1–4 in the input menus) or SW 4>1 (A: the first of four in a row)
A WEFT patch clocks a sequencer	CLK OUT in the patch; that track's TRACK › CLOCK = WEFT
A WEFT patch moves another track's steps	SEQ OUT: TRACK, MODE (STEP, JUMP, RESTART, GATE, PATTERN), A its trigger

19. Questions people ask

A page I saw before is gone.

• It only shows when it applies. SOURCE 3 and 4 depend on the engine. The graph's HEAD pages appear only in GRAPH mode, HEAD 2's only when head 2 is on.
• Holding LFO does not change pages: it puts the macros on the knobs.

The FX page changes a value for every track.

• Only the knob named T_ SEND is per track. Everything else on a bus page is the shared effect.

The graph doesn't seem to do anything.

• Check SEQ › TRACK › MODE is GRAPH.
• Steps need to be on (tap them).
• With no cords, each step just goes to the next one, so it sounds like a normal sequence until you add cords or branches.

The FM-1 crackles, or makes a loud noise.

• The audio is taking longer than it has. Open GLO › CPU: if RENDER is near or over 90 % and XRUNS is counting, that's it. The bars show which part costs most.
• Fewer voices (EDIT › SOUND › VOICES), fewer tracks playing at once, or lower effect sends bring it down. The overload guard fades out voices on its own and then thins the delay's grains and WEFT (EASED on the CPU page); muted tracks stop costing after half a second (SKIP SILENT). VIEW TRACKS on the CPU page shows which track costs most.
• To know this unit's limits, run GLO › STRESS with AUTO.

A long note gets cut off when other tracks play.

• Synth tracks share eight voices between them (strike tracks have four of their own, perc tracks twelve). When every one is sounding, a new note takes one: a voice that is already releasing first, then a note of the track holding the most voices (a chord loses a note before a lone line), the oldest of those. So a held note on a mono track keeps its voice unless every track is down to one.
• If GLO › CPU shows GUARD: n VOICES in red, it is the overload guard, not the voice count: the FM-1 is near its limit and the guard is fading voices to keep up. Lower VOICES on chord tracks (each voice costs, held or releasing), shorten long RELEASE times, or lower effect sends.

Something got loud or stuck.

• Press Panic / stop all (emulator), or stop and start.
• High FEEDBACK REGEN and delay FEEDBK can build up; the master limiter stops it reaching your speakers.

---

Installing on the FM-1

Installing any custom firmware is at your own risk. The installer never touches the FM-1's boot area, and M-VAVE's own firmware can always go back on (below).

1. Open Ravel's site (the repository's GitHub Pages: the emulator) in Chrome or Edge on a computer, and press Install on FM-1 at the top.
2. Connect the FM-1, switched on, directly to the computer with a USB data cable.
3. Press Install, allow MIDI when the browser asks, and wait until it says it is done. Don't unplug part way. The FM-1 restarts into Ravel.

The installer page shows the latest release at the top and installs it unless you choose otherwise: its Version to install list also has the ten most recent releases (an older one warns that projects saved with a newer version may not open in it, so export them first) and, when main has moved on since the last release, the newest test build (dev- and the commit, with its date). The Install button names the version it writes. The FM-1 shows the version it runs on its start screen and on GLO › FLASH.

From the command line instead (pip3 install mido python-rtmidi): python3 tools/fm1_install.py Ravel-FM1.fwsc. The .fwsc is on the site (firmware/Ravel-FM1.fwsc) and on the repository's releases.

The installer works from M-VAVE's own firmware, from Ravel, and from the other community firmwares. To go back, the same page writes M-VAVE's own FM-1 firmware (which you download from M-VAVE) back over the same cable; M-VAVE's own updater, M-UPGRADE, works too.

If the FM-1 will not start

• Hold OCT− and OCT+ for 5 seconds while Ravel runs: the FM-1 goes into its update mode, and the installer can write any firmware.
• Safe mode: if Ravel crashes twice while starting, it starts in a safe mode instead: no sound, USB on, so the web installer can reach it. PLAY tries Ravel again.
• Calibration: hold OCT− and OCT+ while switching on to teach Ravel which button and knob is which, if the panel seems mixed up.
• Last resort: if nothing shows on the screen but the FM-1 appears on USB in the chip's update mode, tools/fm1_rescue.sh (from X0X) puts M-VAVE's firmware back from a Mac. Beyond that, recovery needs the FM-1-transporter.

What's here

Path	What
firmware/app/	Ravel: the engine (rv_engine.c), synth engines (rv_synth.c), strike (rv_strike.c), buses (rv_bus.c), sequencer (rv_seq.c), modulation and clock (rv_mod.c), parameters, presets, projects, and the interface (rv_ui.c, rv_gfx.c). Portable C99, single-precision float, no C library.
firmware/fm1/	The FM-1 side, bare metal: Felucca's hardware layer (hal/), start-up and memory map, the update loader (loader/), and in src/: USB, LCD, storage, the update entry, the panel map, Ravel's platform (plat_fm1.c) and the boot, audio interrupt and main loop (main_fm1.c)
host/	The simulator: the whole app on a desktop, driven by scripts, writing screenshots and WAV files
web/emu/	The browser emulator: the same code compiled to WebAssembly, on a drawn FM-1 panel
tests/scenarios/	Simulator scripts that play the firmware and check it (tour.rvl visits every page; manual.rvl takes the manual's screenshots)
docs/	The signal-flow diagram, and docs/manual/: the panel drawing and the screenshots used in this manual
tools/	The FM-1 build (build_fm1.py, fm1pkg_make.py), the installer and rescue tools, the site assembler (make_site.py), toolchain and SDK-file downloads, font and table generators
web/installer/	The web installer (Web MIDI), from Felucca and X0X
tests/fm1/	Felucca's update-path tests, run against Ravel's package; projstore_test.c, the compressed project store on a simulated flash (power cut at every write)

Building

The simulator (any Unix with a C compiler, and Python with Pillow):

sh host/build_host.sh
./build/host/ravel_host tests/scenarios/tour.rvl build/out    # screenshots and audio in build/out

The browser emulator (clang with the wasm32 target and wasm-ld; no emscripten):

sh web/emu/build.sh          # web/emu/ravel.wasm
node web/emu/test.mjs        # smoke test
python3 web/emu/bundle.py    # build/web/ravel-emulator.html, one file to open in a browser

The FM-1 firmware, on Linux x86-64 (JieLi's clang for the AC791N; on a Mac, X0X's build runs it in Docker):

sh tools/get_toolchain.sh ~/.jieli                     # JieLi's Linux toolchain
sh tools/get_ac79_files.sh ~/ac79                      # three files of JieLi's AC79 SDK the package contains
JIELI_TOOLCHAIN=~/.jieli/toolchain AC79_SDK=~/ac79 python3 tools/build_fm1.py [--release 0.3]

build_fm1.py builds Felucca's update loader and the app (the platform at -Os, the instrument at -O2), checks the image (entry point, no calls from RAM code into flash, no ROM references, no double-precision code, register access only in hal/, the RAM and pool budgets) and packages build/fm1/Ravel-FM1.fwsc. A release build's identity is FM-1_82 and the version as two digits each (0.4.1 is FM-1_82000401); a build without a version is FM-1_82. 82 ("R") is Ravel's own: no other firmware uses an identity starting with it. (0.4.0 and earlier were FM-1_96….)

The site (what the Pages workflow publishes): python3 tools/make_site.py _site build/web/ravel-emulator.html build/fm1/Ravel-FM1.fwsc VERSION.

Publishing: every push to main rebuilds the site (enable it once under Settings → Pages → Source: GitHub Actions); pushing a tag such as v0.3 also makes a release with the firmware and the emulator.

The FM-1 build

Ravel runs bare metal on the FM-1's JieLi AC791N, on the open hardware layer that Felucca wrote and X0X carried on: no vendor SDK, no RTOS. A 10 kHz timer scans the keys, encoders and LEDs and runs USB; the codec's DMA interrupt asks Ravel for 512 frames at a time (two calls of 256), and the main loop draws the interface about 30 times a second.

• Flash: the app is about 200 KB of the 568 KB app slot.
• RAM: the platform uses about 45 KB of the 96 KB main RAM; the instrument's state (voices, buses; the 120 KB the tape used is free) about 280 KB of the 336 KB pool.
• Storage: eight project slots of 32 KB in the flash's data area; the panel calibration beside them.
• USB: MIDI, and USB audio to the computer (Ravel's output, recordable): a class-compliant stereo input, 16-bit at 44.1 kHz, that needs no setting on the FM-1 or driver on the computer. On a Mac it is Ravel FM-1 in Audio MIDI Setup and in any recording app's input list (set the app to 44.1 kHz); on Windows a recording device of that name. One stereo pair, the main mix: no separate tracks over USB. MIDI in on the TRS jack too: notes, CC 1, clock, start and stop (GLO › MIDI IN).
• Not checked on hardware: everything. In particular the CPU load of a dense project (the render runs inside the DMA's deadline; an overrun drops a block; the CPU meter in the top bar shows it, and the TINE and PHYS engines cost the most), and moving projects and sounds over USB (tools/fm1_data.py and the emulator's Send to FM-1).
• Not in this version: Bluetooth, audio input.

Ravel Software

The FM-1 has to fit everything into a small chip, so this firmware keeps only what runs well on it. The fuller version, with every engine and effect it had before (ROOM and CLOUDS spaces, the filter pair, BANDS and the vocoder), lives on as Ravel Software, for the browser: play it here (its manual). The emulator's Software button opens it. It is kept on the software branch and doesn't run on the FM-1.

Licence

GPL-3.0 only (see LICENSE). The FM-1 platform layer, loader, installer and tools are Felucca's and X0X's (GPL-3.0). A firmware package also contains three files of JieLi's AC79 SDK (Apache-2.0). The CZ engine is a port of MAME's uPD933 emulation (BSD-3-Clause). Third-party code is listed in THIRD_PARTY.md.

Credits

• Mutable Instruments (Émilie Gillet) for Beads, whose grains the delay's GRAINS follows (Ravel Software also follows Clouds' reverb in its CLOUDS mode).
• Felucca by Leo Kuroshita (@kurogedelic), Hügelton Instruments: the FM-1's open hardware layer, USB, storage, update loader and web installer that Ravel runs on.
• X0X, a Felucca fork, for the platform as Ravel takes it, the simulator's design, its PNG writer and the build, install and rescue tools.
• The authors of JIANT, SLOOP and sloopDX, and everyone who mapped the FM-1.
• XAOC Devices' Zadar, whose library of morphing shapes the WAVE engine's WAVE ENV follows (the shapes are Ravel's own).
• The screen is set in Ravel's own runic stroke alphabet (tools/runic_glyphs.py: straight strokes only, curves turned into points), drawn at eight times the size and brought down to the screen at 16 levels. The palette is black and greys with bone and verdigris accents; tracks are told apart by colour: synth white, strike slate, tape verdigris, perc maroon.
• Moog's MF-105 MuRF, whose fixed resonant bands and patterns Ravel Software's BANDS bus follows.
• E-mu Systems, whose Z-plane filters the Z filters follow in spirit (the frames are Ravel's own designs).
• Maxime Denuc's Nachthorn and Dorian Concept's SH-101 playing, which the ORGAN and MONO engines are made to sound like (Ravel's own synthesis; no recordings used).
• Elektron's Machinedrum, whose synthesis machines and their documented parameters the PERC tracks are built from (Ravel's own designs; no Elektron code or data).
• Kurzweil's VAST and E-mu's patch-cord functions, whose idea of building sound from function blocks the LOGIC engine follows.
• Wolfgang Palm's PPG Wave and Waldorf's Microwave, whose wavetables, stepping and wave envelope the WAVE engine follows, and Xfer's Serum, whose phase warps it borrows the idea of (the tables are Ravel's own).
• Devin Acker and MAME, whose uPD933 emulation shows how the Casio CZ's sound chip works (the CZ engine follows it; BSD-3-Clause, see THIRD_PARTY.md).