departure: 12 HP, an effect that hears one bar into the future, by daylight noise

One bar late

CLOCK takes quarter notes, and four of them are the bar it waits. Whatever goes in comes out exactly that long after, at full level and untouched, so a groove that repeats every bar lands where it always did. Change the tempo and it follows within a bar, without a click.

The page in the middle is the bar it has already heard: sixteen typed lines, a line a sixteenth, a paragraph a beat. Each hit is written on its line the moment it comes in, swells brighter as its warning plays, and flashes white as it lands.

IN L and IN R: the sound. R follows L when it's unpatched.
CLOCK: quarter notes. Unpatched, it keeps the last tempo (120 BPM at first).
OUT L and OUT R: the sound a bar late, the warnings in it.

The warning

Every hit it counts gets a warning that starts ahead of it and stops dead as the hit lands, so the hit itself comes through clean. The swell is a reversed reverb of the hit rising into it, the sound of a snare's reverb played backwards, made for every hit on its own.

DARK takes the warning over: the hit itself, pitched down, in pieces playing forwards and backwards, creeping in early and growing into the hit. Turned all the way, it's a voice under the floor.

AHEAD: how early each warning starts, in musical lengths from a sixteenth to the whole bar.
SWELL: none to a wash.
DARK: clean to muttering, an octave down at full.
SENSE: what counts as a hit. Down, only the loudest; at noon, the kick and the snare; up, every transient.

FORETOLD and RISE

The rest of the rack can hear the future too. FORETOLD fires as each warning starts: play a note an eighth before every snare. RISE climbs into every hit and falls the moment it lands: open a filter before the kick, or turn it over and duck a pad, already down when the kick lands.

FORETOLD: a 5 V trigger, 8 ms, at the start of each warning.
RISE: 0 to 8 V, from the start of each warning to its hit, back to 0 in 8 ms.

The panel

Twelve HP, every part on the line's staggered grid and mirrored about the middle. The page fills the middle: sixteen typed lines of circuit board lit from behind, every word its own window. The art is a typewriter in gold dots, the paper a sheet of gold.

IN L and IN R at the top corners; AHEAD and SWELL beside the page, SENSE and DARK below them.
FORETOLD and RISE down the edges, CLOCK under the page, OUT L and OUT R at the foot.

Inside

One four-layer board sits 10 mm behind the panel, with the jacks, the knobs and 32 RGB LEDs on its front and everything else on its back. Two lights sit under each line, in a channel of a printed black block that walls every line off from the next, so a written line glows beside a dark one. An RP2350 runs the engine on both its cores, 46,875 times a second, and keeps the bar it waits in 8 MB of PSRAM. RISE comes from a 16-bit DAC, calibrated over USB with a meter.

The DEPARTURE panel with a bar written on its page: lines lit in lamplight, the third beat's line swelling, with its knobs on.

Specs

Format

Width: 12 HP
Depth: about 21 mm behind the panel, to the top of the power header (estimated)
+12 V: about 130 mA with the page dark, about 160 mA in a busy bar, 205 mA at most (estimated)
−12 V: about 6 mA (estimated)
+5 V: not used; 10-pin header
Panel: 1.6 mm FR4: sixteen typed lines of bare board, lit from behind; gold through black mask
Controls: 4 knobs, AHEAD on eight steps

I/O

IN L, IN R: ±9 V full scale; R follows L unpatched
OUT L, OUT R: ±5 V full scale, soft-limited
CLOCK: quarter notes, 60 to 200 BPM; a rising edge through about 1.2 V
FORETOLD: 5 V, 8 ms, as each warning starts
RISE: 0 to 8 V into each hit, 16 bits

Engine

Brain: RP2350, both cores, 46.875 kHz, 32-bit float
The bar: 4.6 s at most (60 BPM), 16-bit, in 8 MB of PSRAM
Warnings: up to eight at once, each with its own reverb
Light: 32 RGB LEDs behind the page, their current capped
Firmware: over USB-C or the debug header, on the back