cernunnos

20 HP · an echo that grows antlers

A forking echo. Every echo of a hit splits in two, one branch pitched down and one up, three generations high: a pair of antlers across the stereo, every tine lit blood red as it sounds. SHED drops them all.

The CERNUNNOS panel: a stag's skull with a full head of antlers, from straight in front. The skull in gold dots hangs down the middle of the panel to the maker's mark; the antlers rise either side of the big knob GROW (printed SPIKE to CROWN) to the top corners, seven tines a side, every dot of them pale bone. IN at the top, SHED's round button under GROW. White labels for the small knobs REACH and SPREAD, and VELVET (SOFT to BONE) and RUT (SPAR to LOCKED), either side of the skull, and down the edges the jacks CLOCK and SHED (each marked with a pulse), GROW CV and SPREAD CV, OUT L and OUT R. cernunnos 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. Press SHED (a click, Space or Enter) and every tine falls.

Everything but the spoken lines is made in the page as you listen. Headphones help: the antlers spread across the stereo.

example patches

The sound and the lights here are CERNUNNOS's own engine, the module's firmware, running in your browser: every fork, its pitch, its place in the stereo and its light. The drums, the bass, the pad, the stab and the voices are stand-ins for the rest of a rack.

A hit grows antlers

Whatever comes into IN echoes, and every echo forks: one branch a SPREAD lower, one a SPREAD higher, three generations high, seven tines an antler. The left antler plays at OUT L, the right at OUT R, the dry hit in both. The further a tine grows, the further out it sits in pitch and in the stereo, and the quieter it is.

The panel

Twenty HP, every part on the line's staggered grid and mirrored about the middle. The art is a stag's skull with a full head of antlers in one hard light: the skull in gold dots down the spine, the antlers rising either side of GROW to the top corners. Every dot of the antlers is bare board, pale as bone in room light and lit blood red from behind, zone by zone as each tine sounds, so a hit climbs from the skull to the crown. Cernunnos is the old horned god, the god of death, whose antlers die every year and grow back.

Inside

Lift the panel: behind the antlers a black baffle holds fourteen cells, one a tine, each the shape of its zone, with 74 lights at their feet. One RP2350 runs it all on both cores, the last seven seconds kept in 8 MB of memory beside it.

The CERNUNNOS panel with its crown lit, the knobs on.

Drag to look around.

Specs

Format

Width
20 HP
Depth
about 21 mm behind the panel, its power header included
+12 V
about 140 mA, 225 mA at the most (the antlers at their cap, SHED lit)
−12 V
about 10 mA
+5 V
not used; 10-pin header
Panel
1.6 mm FR4: ENIG gold through black mask, white labels, the antlers bare board
Controls
5 knobs, GROW's big; SHED, a lit button

I/O

IN
audio, ±5 V with room to ±9; 100 k
CLOCK
a pulse a beat, high past about 1.1 V; 100 k
SHED
gate, the same
GROW CV, SPREAD CV
±5 V across half the knob's travel; 100 k
OUT L, OUT R
±5 V at most, 1 k; OUT R summed into OUT L while unpatched

Engine

Brain
RP2350, both cores, 46.875 kHz, 32-bit float
Converters
PCM1808 in, PCM5102A out, on one I2S clock
Memory
8 MB PSRAM: 7 s of what goes in, at four rates
Echoes
14 tines, 20 ms to 6 s, up to three octaves either way
Light
74 RGB LEDs behind the antlers, their current capped at 150 mA together
Firmware
over USB-C or the debug header, on the back