Stencilcuts held sound into rhythm

Feed Stencil something that holds still: a pad, a string section, a drone, a noise wash. It opens and closes a gate in a repeating pattern, so the held sound comes out as rhythm. Where the pattern says open, you hear the sound. Where it says closed, you hear the gap.

Every opening has a shape, the slice envelope: how fast it opens (ATTACK), how long it stays open (GATE), how slowly it closes (RELEASE). Short, hard slices give the staccato trance gate. A long release that spills into the next step gives the loose, breathing pump of sidechain compression. Turn on DUCK and the level dips on each step instead of rising.

The gate doesn't have to be a volume control. Turn up FILTER and the gaps become a lowpass filter closing down, carving the highs away rather than muting, so the rhythm is in the brightness.

The pattern can come from a bank of sixteen, from an even Euclidean spread, or from a word. Type a word on the web page and Stencil spells it in Morse code: a dit is a short opening, a dah a long one. FIT sets it on the bar, so a name loops as a one-bar or two-bar phrase.

Bank (amber). PATTERN picks one of sixteen factory patterns or the user pattern at the far right. STEPS on the Shift page sets the loop length from 1 to 32; patterns repeat to fill it. The user pattern keeps its own length, set on the web page.

Euclid (green). PATTERN is the number of hits, from none to STEPS. The hits spread as evenly as they can and always start on the one.

Morse (cyan). PATTERN picks one of the eight stored words, and STEPS becomes FIT. See Morse.

R OFFSET (Shift) delays the right channel's pattern by up to eight steps either way, so the two sides answer each other. At zero they match.

PATTERN's ring shows the pattern: one LED per step, open steps lit in the source's colour, the playhead white. A pattern longer than the ring is shown a ring's length at a time.

Every open step starts the same shape. The level rises for ATTACK, holds until GATE of the way through the step, then falls for RELEASE. All three are fractions of one step, so they scale with RATE and tempo. RELEASE runs to 400%: a slice can take four steps to fade, overlapping the next ones. That overlap is what makes the pumping feel loose instead of chopped.

DEPTH is how far the closed parts close: 100% is silence, 50% halves the level. CURVE (Settings) bends the slope: Snappy rises fast and falls slow, Slow the other way.

DUCK turns the shape upside down: each open step pulls the level down, and RELEASE is how it climbs back. Pattern 4 (quarter notes) with a short GATE and a long RELEASE is four-on-the-floor sidechain.

FILTER (Shift) moves the gate from volume (0%) to a 12 dB-per-octave lowpass that sweeps between 30 Hz and 18 kHz with the envelope (100%). Halfway, each does half the work.

In Morse, every letter is short and long openings: a dit is one step open, a dah three. There's one step closed between the parts of a letter, three between letters, and seven between words and at the end of the loop. A run of open steps (a dah) holds open as one slice, even with a short GATE.

A word spells to whatever length it spells. PARIS is 50 steps, twelve and a half beats, so on its own it would drift against the bar. FIT fixes that. In Morse, the STEPS knob on the Shift page is FIT, and its ring shows six zones:

The words page is how words get onto the module. Type into one of eight slots and it shows the spelling, the tape and the loop length. Pick a FIT and press Play to hear it gate a pad in the browser. Then send it.

With nothing in J3, Stencil runs at TEMPO (40–240 BPM, Shift page), or at the tempo you tap on B2. A clock in J3 takes over: Stencil measures the tempo from the pulses and lines every step up with them, so it stays on the grid even when the clock wanders. Two seconds without a pulse and it goes back to TEMPO.

Tell it how many pulses make a beat in Settings → Clock In: 1 (quarter notes), 2, 4 (sixteenths, what most sequencers send) or 24 (MIDI-rate clock).

A pulse into J4 puts the pattern back to step 1. If it arrives within 5 ms after a clock pulse, that clock pulse becomes step 1, because a sequencer's clock and reset rarely land on the same instant. Later than that, the pattern waits at step 1 until the next clock pulse. In Morse with FIT set to bars, reset is what puts the word on the downbeat.

RATE sets the step length: 1/32, 1/16T, 1/16, 1/8T, 1/8, 1/4T, 1/4, 1/2 or a whole bar. SWING (Shift) delays every second step by up to half a step.

The screen shows the source and its pattern, the tempo (bpm free, clk locked), the pattern as a strip of cells with the playhead, the word in Morse mode, and two envelope bars. Under that is the menu: turn the encoder to move, push and turn to change. The rows are Source, Word, Fit, Rate, Steps, Attack, Curve, Filter, Reso, Mode (Gate/Duck), Swing, R Off, Mix, Tempo, ClkIn, Input and Mods.

Typing a word on the Patch. Click (push and let go) on the Word row. Turn to change the letter under the cursor, click to move to the next letter, push and turn to move the cursor back, hold for a second to finish. Its Morse shows under it as you go.

Settings and words save themselves two seconds after the last change. Mods (push and turn) opens the module picker to switch to another firmware on the card.

Settings: hold B2 and B3 together for two seconds. P1 is brightness, P2 Curve, P3 and P4 the preset slot and save/load, P5 Clock In, P6 Input (Stereo / Mono L). B1 moves to the next settings page, the SD firmware picker.

Stencil saves itself: five seconds after you stop changing things (sooner if you keep going for half a minute) everything goes into its own preset slot, slot 4 on the module (3 counting from zero). That covers both pages, the settings, the eight words, the user pattern, the source, Gate/Duck and the tempo. Switching to another firmware on the card and back brings it all back.

Download stencil_alchemy.bin (Alchemy Lab) or stencil_patch.bin (Daisy Patch): an early build, not yet played on a module. To install, put stencil_alchemy.bin in the card's /alchemy folder and pick it with the SD picker of whatever firmware is running. See Get it on your module. On the Patch, stencil_patch.bin goes in /modules.

Stencil has been written and tested on a computer: hundreds of automatic checks on the timing, the Morse spelling, FIT, the clock, reset and the filter, and a test that the words page spells every word exactly as the module will. It has not yet been played on a module. Until it has, these are the things most likely to need a fix: