manifest

20 HP · the ghost of what left, printed

A spirit photograph of the sound.

The MANIFEST panel: under the name, a face under a burial sheet drawn in faint dots of bare board down the middle of the black panel, two gold coins on the sheet over her eyes, the sheet falling toward the printer below. White labels for the big knobs LINGER (printed GONE to STAYS) and HAUNT (ALONE to TAKEN), the small knobs WHISPER (VOICE to BREATH) and FACE (DEAD to OTHER), and the jacks IN, SUMMON, OUT L and OUT R. The bottom half is a thermal receipt printer's face: its paper slot with tear teeth across the top and its FEED key in the corner. manifest at the top, daylight noise at the bottom.

Turn a knob: drag it, roll the wheel over it or use the arrow keys; a double click puts it back. Hold SUMMON down to call her, press FEED on the printer for blank paper, and pull the paper down (or click it) to tear it off.

Everything but the four spoken lines is made in the page as you listen. She only comes when something leaves, once in each patch. Headphones help: the ghost is wide.

example patches

The sound, the paper and the light here are MANIFEST's own firmware running in your browser, bit for bit: what it hears, when she comes, the ghost it sends back, every dot it prints and every LED behind her face. The drums, the bass, the pad, the lead and the voices are stand-ins for the rest of a rack.

She comes when something leaves

MANIFEST listens to IN and keeps track of what's been playing, in twelve bands from 60 Hz to 11 kHz. A part counts once it's played for three seconds. When it stops (the drums drop out for a breakdown, a voice finishes its line, a cable's pulled), she comes, about a second after its last sound. A part that's always left gaps of its own (a pluck every few seconds) has to be gone longer than its gaps.

She's made of what's missing and nothing else. MANIFEST keeps the last five seconds of IN, and she plays back the two seconds before the part left, slowed down, through only the bands that went quiet: if a voice stops and the pad under it plays on, the pad stays out of her. If the part returns while she's there, she goes.

A loop that keeps going never brings her. Neither does a chord change, a filter closing or a slow fade: she only comes when something stops.

The ghost

OUT L and OUT R send her back, wide across the stereo, with none of the dry sound in them, and they're silent until she comes. The rest of your case carries the dry sound.

LINGER, GONE to STAYS: how slowly she plays it back. At GONE she plays the two seconds at their own speed and is gone in two. Halfway she's four times slower and stays eight; at STAYS she's sixteen times slower and stays half a minute. She rises at the start and fades as she reaches the moment it left.
WHISPER, VOICE to BREATH: at VOICE the partials stay in tune however slowly she goes, so a voice or a chord is still itself. Turning up, their phases are thrown about and the spectrum blurs, until at BREATH no pitch is left: noise in the part's shape, a voice's words coming back as breath.

Her face

HAUNT sings a face into the ghost's spectrum, one line of the picture for each line of paper, across the same bands the printer prints. So she's in the sound, a hiss with a shape, and the printer draws her back out.

HAUNT, ALONE to TAKEN: at ALONE the ghost is only what left. Turning up, she comes through it, faint and then strong; at TAKEN she's most of it.
FACE, DEAD to OTHER: which face she sings, from the faces of the dead to things that never were. Between two, one wears away into the next.

Her face rises a quarter of a second after the ghost, chin first, 64 mm tall, once each time she comes. On the panel, her face lights while she's here, rising out of the printer.

The paper

A 58 mm thermal receipt printer fills the bottom half of the panel, and it only runs when she comes. Then it prints one plate: the spectrogram of IN and the ghost together, a line of 384 dots about every 11 ms, the lowest sounds on the left from 60 Hz and the highest on the right up to 11 kHz. Loud is black. It starts from just before the part left, catches up, and prints on while she sings until her face is out. Then it captions the plate with the time and DEPARTED, and feeds it out past the teeth.

It prints upside down, so the plate hangs the right way up: the caption, her face, and under her chin the moment it left. A plate is about 11 cm, and a song brings a few. The printer's own FEED key feeds blank paper, and the paper tears off at the teeth.

Summon

SUMMON is a gate in. When it rises she comes at once, made of everything she's heard in the last two seconds, whether anything has left or not, and the plate is captioned SUMMONED. While the gate's high she doesn't leave: she waits on one moment, breathing, as the sound moves on underneath. When it falls she fades and is gone. Held while she's there for something that left, it holds her too.

The panel

Twenty HP, every part on the line's staggered grid and mirrored about the middle. Down the spine is a face under a burial sheet, with a gold coin on the sheet over each eye. The coins are gold. Her face is a screen of bare board dots, faint until she comes; then it lights a pale green-white from behind, rising out of the printer, and the coins go dark in the glow.

IN and SUMMON in the top corners, SUMMON marked with a pulse.
LINGER and HAUNT, the big knobs, either side of her head; WHISPER and FACE under them.
OUT L and OUT R at the edges, between the two rows of knobs.
The printer in the bottom half, its FEED key and light in the corner. The jacks keep to the outer columns, so no cable ever hangs in front of the paper.

Inside

The printer clips into the panel and comes off with it. Behind the panel the main board sits over the printer's body, and on the board a black light box surrounds her face, fifteen LEDs at its foot. One RP2350 does it all: one core listens and plays, the other works out the ghost, her face and every line of paper.

The MANIFEST panel printing, her face lit, a plate hanging from the printer.

Drag to look around.

Specs

Format

Width: 20 HP
Depth: 42.1 mm from the panel's face: the printer
+12 V: about 140 mA standing by; about 640 mA while it prints (estimated)
−12 V: about 10 mA
+5 V: not used; 10-pin header
Panel: 1.6 mm FR4: ENIG gold through black mask, white labels, her face in bare board dots
Controls: 4 knobs, LINGER's and HAUNT's big

I/O and paper

IN: audio, ±5 V with room to ±9; 100 k
SUMMON: gate, high past about 1.2 V; 100 k
OUT L, OUT R: the ghost only, straight to 5 V, a soft knee to 8 V; 1 k
Paper: 58 mm thermal receipt paper, a 30 mm roll, loaded from the front
Printing: only when she comes: a plate of about 10 cm at 11 mm/s, 384 dots a line

Engine

Brain: RP2350, both cores, 46.875 kHz, 32-bit float
Converters: PCM1808 in, PCM5102A out, on one I2S clock
Memory: 8 MB PSRAM: the last five seconds of IN, her plate, the paper's queue; fourteen faces in flash
Light: 15 RGB LEDs behind her face, their current capped at 60 mA together
Firmware: over USB-C or the debug header, on the back