GLTCH: stutter and glitch effect

GLTCH is a tempo-synced stutter and glitch effect for TheRaK, in the spirit of Sugar Bytes Effectrix and Ableton's Beat Repeat. You draw blocks on a step grid, one row per effect, and each block switches its effect on for those steps. GLTCH has 11 lanes: five that play with time (Repeat, Reverse, Tape Stop, Scratch, Stretch), four that color the sound (Crush, Filter, Gate, Pitch Shift) and two throws (a delay and a reverb). A Beat Repeat engine (the BEAT REPEAT tab) adds repeats of its own. A bank holds 12 patterns. You switch patterns from the panel, with MIDI keys or with automation, and every switch lands in time.

The repeat grid goes down to 1/256, with triplets (1/256T).

In this version GLTCH lives inside TheRaK only; in a game it plays inside a saved rack, through the TheRaK Performer component (see TheRaK Performer (gameplay)) or a printed track. Add it from + Add Device > EFFECTS > GLTCH, or type GLTCH.Open in the console. That command opens TheRaK and, when the rack has no GLTCH, adds one at the end of the last chain. If the rack has no chain yet, it first adds a DrumKing with an STPR-1 in Drum mode (or an Afterglow with an STPR-1).

A GLTCH processes the chain it sits in, like any other TheRaK effect: select an instrument, add GLTCH, and it lands directly below that instrument. It follows the chain's clock, so every block, repeat and gate is sample-accurate on the rack's tempo, in the jam and in a printed track alike.

Each GLTCH also gets a number, counted across the whole rack: GLTCH1, GLTCH2 and so on. The number names its automation controls (see Automation) and is kept when you move the device; the card itself shows the device's name, GLTCH until you rename it.

A new GLTCH starts with a copy of the Subtle Stutter factory bank. Every bank in a rack is the device's own copy: editing it never changes the bank asset you loaded it from.

Unfold the GLTCH card to see its panel, from top to bottom:

• Pattern slots [1] .. [12]. Teal marks the pattern you edit, which is also the one the jam plays; orange marks the pattern that is playing now. A switch waiting for its quantize point blinks. The ... button next to the pattern name copies the edited pattern to another slot or clears it.
• Header row: switch quantize, run mode, master mix and mix law, output level, smooth, seed, the MIDI select root note, and GLTCH's own CPU readout (see CPU and memory).
• Tab row: the LANES and BEAT REPEAT tabs choose the page below; a light next to them shows while Beat Repeat or the REPEAT button repeats; then the status line (hints and refusals); the REPEAT button sits at the right end, so it works from either page.
• The LANES page:
  • Loop bar above the grid: loop start and end handles, the number of steps, the step rate and swing.
  • Lane grid: the 11 lanes in three groups, TIME, TONE and SPACE, with the steps of the pattern across. A lane header shows the lane's name, an on/off switch, the lane's mix bar and an activity light.
  • Mod strip: the knobs of the selected block's lane, its chance and mute, and one modulator row per knob.
  • Dice: lane toggles, an intensity knob and the Dice button.
• The BEAT REPEAT page: the Beat Repeat settings (see Beat Repeat).

• Paint: drag across empty cells of a lane. Each drag paints one block in the lane where you started it.
• Erase: right-drag, or Alt-drag, over blocks of one lane.
• Move a block by dragging its body; resize it by dragging an edge.
• Select a block with a click; its knobs appear in the mod strip. Delete erases the selected block (a click in the grid gives it keyboard focus). Without a selected block Delete does nothing in the grid: to delete the GLTCH device itself, click its card in TheRaK's device list and press Delete there.
• Escape during a drag cancels it; a lane mix drag goes back to where it started.
• Lane on/off: click a lane header. An off lane keeps its blocks and plays none of them.
• TONE order: drag a TONE lane header up or down to change the order the TONE lanes process in. TIME and SPACE lanes keep their places.

Every gesture is one Undo step, and so is every knob drag from start to finish. A new Filter block starts with a sweep from 18 kHz down to 400 Hz; blocks on other lanes start with the lane's settings.

A pattern has 1 to 64 steps. The step rate is 1/32, 1/16T, 1/16 (the default), 1/8T, 1/8 or 1/4. The loop bar selects the steps that repeat: a pattern plays steps loop start to loop end over and over, and blocks outside the loop are kept but not played. Swing delays every odd step by up to half a step. It follows the same rule as STPR-1 and SQLCH, so a swung GLTCH lines up with a swung sequence.

Blocks on different lanes can overlap; blocks on the same lane never do.

TIME lanes read GLTCH's recording of the recent input (its history). Only one of them drives the sound at a time, in this order of priority: Tape Stop > Scratch > Stretch > Repeat (a drawn block) > Repeat (the REPEAT button) > Beat Repeat > the live input. When the highest active one ends, the next one takes over with a crossfade. Reverse is special: it flips the direction of whichever TIME lane drives the sound. When no other TIME lane is active, Reverse plays on its own.

TONE lanes process the output of the TIME stage inside their blocks. The default order is Pitch Shift, Crush, Filter, Gate. Each block fades its lane in and out over 2 ms.

SPACE lanes are throws: a block opens the send to the delay or the reverb for its steps. The echoes and the reverb tail keep ringing after the block ends.

Each lane also has a Mix (0–100 %: the wet amount of a TIME or TONE lane, the return level of a SPACE lane) and a law (the four mix laws). Parameters you do not set on a block use the lane's default, else the default below.

Repeats a slice of the audio at the block's grid. The first slice of a block plays live, and every following slice repeats it, so the attack you hear first is always the real one.

A Retrigger repeat keeps replaying the audio captured at its start, and so do Beat Repeat captures and the REPEAT button. GLTCH's history holds about 10.9 seconds at 48 kHz, so a capture held longer than that (a long block or a held REPEAT at a slow tempo) fades out when its audio leaves the history; its repeats are then silent (Insert, Gate) or leave the live sound alone (Mix). Rolling repeats always use fresh audio.

Over another TIME lane, Reverse plays that lane's repeats, grains or tape backwards instead; the live first slice of a repeat stays forward. A Mirror longer than GLTCH's history fades to silence instead of wrapping around.

The sound fades out over 5 ms once the tape is nearly stopped, and the block's end returns to the live sound over 10 ms. A tape falls further behind the live sound as it plays (reversed, about twice as fast); if a very long block takes it past the start of GLTCH's history (or, reversed, back to where playback started), it fades out there instead of cutting off.

A scratch never moves past the start of GLTCH's history.

A freeze (Factor 0) loops the audio just before the block. It holds for about 10 seconds at 48 kHz, the length of GLTCH's history, and then fades to silence.

Even at Drive 0 % the saturation stage rounds the signal slightly: quiet sounds come out about 2 dB louder, and full scale stays full scale.

Frequency changes are smoothed, so sweeps never zipper.

The shifted sound is about half a Window late (25 ms at the default 50 ms). A Pitch Shift block starts with sound, because the shifter keeps listening between blocks. Short windows suit high sounds: below about 250 Hz the 10 ms Window cannot hold the pitch steady, so use 50 ms or more for bass.

A frozen reverb stops taking in new sound. Put a throw block right before a Freeze block, so the freeze has something to hold (the Frozen Space bank does this).

The Repeat grid, the Beat Repeat grid, the Gate rate, Reverse slices, the Scratch rate and synced delay times all use one list of grid values:

• straight: 1/1, 1/2, 1/4, 1/8, 1/16, 1/32, 1/64, 1/128, 1/256;
• triplet: 1/2T, 1/4T, 1/8T, 1/16T, 1/32T, 1/64T, 1/128T, 1/256T;
• dotted: 1/2D, 1/4D, 1/8D, 1/16D, 1/32D, 1/64D.

A grid value is 4/n quarter notes: 2/3 of that for a triplet, 1.5 times for a dotted value. The finest grids are only a few milliseconds long:

At these rates a repeat is a pitched buzz, not a rhythm. Blocks at 1/128 and finer (1/128, 1/128T, 1/256, 1/256T) show a buzz icon in the grid. Repeat and Gate onsets are placed exactly: at 1/256T and 174 BPM, a thousand slices drift by less than one sample. Every change of slice crossfades over the Smooth time (1 ms by default, 0.1–5 ms in the header). The crossfade is at most a quarter of a slice and at least 16 samples, so even 1/256T repeats do not click.

Chance. Every block has a chance, 0–100 %. On each pass of the pattern, a block with a chance below 100 % plays or rests by a seeded roll. The roll depends only on the bank's Seed (header row), the pass number and the block, so the same seed plays the same sequence every time: in the jam, in a print and in PIE. Change the seed for another sequence. Mute silences a block without deleting it.

Modulators. Every knob of a block can have one modulator (the mod strip's rows), and a block plays at most 8 of them: the mod strip refuses a ninth and says so. A bank made elsewhere (a JSON import, or a script) can still carry more: such a block plays its first 8, in list order, and DAWntless logs one warning per bank when the bank loads or is imported, naming each such block ("GLTCH bank <path>: <n> block(s) carry more than 8 modulators; each plays its first 8: ..."). The warning never repeats while the bank plays.

• Raw: no modulation;
• From → To: moves from the block's value to Target over the block. Slope bends the curve: 0 is straight, above 0 starts slowly, below 0 starts fast. Frequencies and times move evenly on a musical (logarithmic) scale. A grid moves by note length and stays in its own kind (straight, triplet or dotted): 1/16 → 1/64 passes 1/32, and a 1/16 heading for 1/64D ends on the straight grid nearest in length (1/32);
• LFO: swings around the block's value by Amount (a fraction of the knob's range) at Rate (in quarter notes per cycle, 1/64 to 16), starting at Offset into the cycle, with a Sine, Triangle, Saw Up, Saw Down, Square or Random shape (a new seeded value each cycle). A grid swings through the grids of its own kind only.

When a modulated value takes effect depends on the knob:

• once per slice, cycle or grain, held until the next one: the Repeat lane's Grid, Pitch, Pitch Decay, Volume Decay, Slice Gate, Direction, Capture, Size and Pan Jump (per slice); the Reverse Slice length (per slice); the Scratch Shape, Rate, Fader and Skew (per stroke); the Stretch Grain and Jitter (per grain). The Tape Stop knobs and the Reverse Mode are read once, at the block's start. A Repeat Grid that changes at a slice starts a new grid from that slice on;
• continuously (every 16 samples, smoothed): the Repeat band filter, the Scratch Depth, the Stretch Factor, every Delay Throw and Reverb Throw knob (Send included), and every TONE knob.

A TIME block only starts at its start. When playback begins in the middle of a Repeat, Reverse, Tape Stop, Scratch or Stretch block (after a seek, a pattern switch or a loop), that block waits for its next pass rather than repeating audio from before you started. TONE and SPACE blocks join at once.

Beat Repeat captures and repeats audio on its own schedule, without drawn blocks:

A capture happens at the song position origin + n × Interval + Offset, and the origin is where the jam started, or where a print starts. With the classic settings, Interval 1 Bar, Offset 12, Grid 1/16, Gate 4, each bar the last beat is replaced by repeats of its first sixteenth. The first slice of every capture is live; the slices after it repeat it. A drawn Repeat block always wins over Beat Repeat.

REPEAT (the button at the right end of the tab row) is a momentary Beat Repeat. While you hold it, GLTCH captures at the next grid point and repeats with the Beat Repeat settings' grid, pitch, decays and mode. It ignores On, Chance, Interval and Variation. It works while the rack is stopped too, on a free-running clock at the jam tempo.

Switch quantize (header row) decides when a new pattern takes over:

• NextStep: at the next step of the playing pattern (the default);
• Beat or Bar: at the next beat or bar of the song;
• PatternEnd: when the playing pattern finishes its loop.

A switch changes which pattern is read, not where you are in the song. The new pattern plays from the point the song has reached in it, counted from the origin, as if it had been running all along. So a pattern designed around the bar stays on the bar, and a print, a seek or a loop sound the same as playing straight through.

Run mode (header row):

• Host: the pattern runs while the rack or the sequence plays (the default);
• Manual: a pattern plays only while you hold its MIDI key, starting at the next step;
• Hold: a key starts or switches a pattern; the same key again stops it.

In Manual and Hold, keys work while the rack is stopped too, on a free-running clock at the jam tempo.

MIDI select. Give the GLTCH focus with its K key (or by selecting it, when focus follows selection). Twelve keys then select patterns 1 to 12: the select root note in the header row selects pattern 1, the key above it pattern 2, and so on. The root is 48 (C3) by default, in the naming where middle C is C4 = 60, so C3 to B3 select patterns 1 to 12. Other keys do nothing. A key selection switches on the bank's quantize. Clicking a slot in the panel brings back the pattern you edit.

A printed chain's track lists GLTCH's controls under Add MetaSound Automation, named after the device's number:

Bypass is an on/off switch, not a lane, so the automation menu does not offer it. Bypass GLTCH with the card's (o).

These controls are read once per audio block, and the Sequencer sends them at game-tick time. An automated switch on NextStep can therefore land one step apart between two playbacks. Automate Pattern and Repeat with the bank's quantize on Beat or Bar and every playback switches at the same point.

The header row's master mix (0–100 %, scaled by GLTCHn_Mix), law and output (−24 to +12 dB) apply to everything GLTCH outputs. That includes audio GLTCH did not change, and it applies the same way whether a block plays or not:

At the default settings (Equal power, 100 %, 0 dB) GLTCH passes audio through untouched between blocks, bit for bit. Choose Linear when you want a partial mix without a level change.

(o) on the card bypasses GLTCH with a 10 ms crossfade. While bypassed, no block, capture or repeat starts, and the throw echoes and reverb ring out. Once they are silent, the output is exactly the input. Bypass never rebuilds audio.

Echoes and reverb tails also ring past the end of their blocks, past a pattern switch and past a stop. A seek or a loop ends TIME effects with a 2 ms fade; the history is kept.

When a structural edit rebuilds a chain while it plays (a generation swap), the old chain fades out over 1.5 s while the new one fades in. The old GLTCH starts no new repeats during that fade. The new GLTCH starts on the bank's pattern: a pattern you selected with a MIDI key does not carry over. If you are holding REPEAT, the panel applies it to the new chain again.

GLTCH prints as part of its chain: the printed track holds a snapshot of the bank and plays it sample-accurately.

• Jam bar n is printed bar n. The pattern and Beat Repeat count from the print's start, just as the jam counts from its launch.
• GLTCH never reads audio from before that origin. A repeat, reverse, scratch or stretch at the very start plays silence rather than whatever the arrangement played before the print, and a Pitch Shift block at the very start opens with about half its Window of silence. So a print sounds like the jam even when the arrangement plays other material before it.
• Re-roll in the Print dialog (STPR-1 Drum Mode probability) does not change GLTCH. GLTCH's chance comes from the bank's Seed, so the print plays the jam's rolls. Change the Seed to hear other rolls.
• Latency. DAWntless reports no latency to the host and does no delay compensation. GLTCH adds none, except that the Pitch Shift lane's shifted sound is about half its Window late.

The dice replace the blocks of the lanes you toggle on with a random, seeded set; other lanes, the pattern length, the loop and the Beat Repeat settings stay as they are. Intensity runs from subtle to extreme:

• at 0 the toggled lanes are cleared;
• above 0, blocks of 1, 2 or 4 steps cover about 15 % + 60 % × intensity of each lane's steps;
• higher intensity picks wilder values: Repeat grids from 1/8 down to 1/256T, pitches up to ±12 st × intensity, and chances down to 100 % − 50 % × intensity.

The same seed and intensity always give the same pattern, and a roll is one Undo step.

The banks are in DAWntless Content > Examples > GLTCH > Presets (DA_GLTCH_*). Each has 12 patterns, from 01 Subtle to 12 Extreme: slot 1 is the bank's basic idea and every slot after it pushes further. Load one from the card header's preset browser; Save As stores your version under /Game/DAWntless/GLTCH/Presets.

The banks are plain data and reference no other asset, so they cook in every configuration.

Two example racks in DAWntless Content > Examples > Rack use GLTCH:

• DA_Rack_BloomBeat (120 BPM): Drums, a DrumKing with the Bloom Studio kit (−3 dB) played by an STPR-1 in Drum mode (pattern A2), into a GLTCH with the Glitch Grid bank; and Keys, an Afterglow with the Glass Drift sound (−8 dB) played by an STPR-1 (D5, Basement progression), into a Stereo Delay (a dotted eighth, 0.375 s, feedback 0.3, mix 0.2). The rack's GLTCH plays its own copy of Glitch Grid, made before the bank's crush ramp and dice were re-voiced: its pattern 1, the one it plays, is the same as the bank's; load the bank again from the preset browser to get the current patterns 2–12.
• DA_Rack_ThumprAcid (128 BPM): Thumpr, the Thumpr FM Drum into GLTCH1 with the Beat Repeat Classic bank; and Acid, SQLCH into a Stereo Delay (a dotted eighth, 0.352 s, feedback 0.35, mix 0.18).

Load one, press Play jam, and unfold the GLTCH card to watch its pattern play. Like every factory rack, they are never overwritten: Save as stores your version.

• CPU. With every lane busy, GLTCH stays within 250 µs per 480-sample audio block (measured as the 95th percentile) and uses almost nothing while idle or bypassed. Echo and reverb tails count as busy until they have died away: a reverb at Size 70 % rings for about 10 seconds after its throw. The panel's header shows GLTCH's own CPU time, and it turns orange above 250 µs. The card header's CPU readout appears on instruments only and covers the whole chain.
• Memory. Each GLTCH holds about 6 MiB: about 11 seconds of stereo history at 48 kHz (4 MiB), the 4-second throw delay and the reverb. The memory is released about 2 seconds after its chain's graph stops, when a structural edit replaces the graph or the rack powers off.

• GLTCH is available inside TheRaK only: there is no standalone GLTCH window, and a game plays it inside a rack (the TheRaK Performer, or a printed track).
• A MIDI pattern selection does not survive a chain rebuild while playing: the new chain starts on the bank's pattern.
• Pattern and Repeat automation is read once per audio block: quantize switches to Beat or Bar for repeatable results.
• Perform keys and a latching REPEAT come in a later update.