barrels

something's down there

20 HP

Audio in, three CVs out. Whatever you patch in is the thing under the water: you never hear it here, you see it by three barrels on lines harpooned into it, each one's height a voltage that rides it with a body of its own. When it dives it takes all three under, and they burst back up.

The BARRELS panel: black, gold dots of the sea seen from under the water, the lit surface overhead round the name. Three barrels across the top are windows of bare circuit board, each cut by its hoops into seven bands, on a row of short lit dashes for the waterline, and from each a rope runs down and in to meet the others at the foot. DEEP and DOWN's jack under the barrels with the DOWN button between them, LINE and DIVE either side of the big WEIGHT, the CV jacks, SWELL under WEIGHT, HEAD, BACK and TAIL at the foot of the barrels' columns, UNDER and SPLASH in the corners. barrels at the top, daylight noise at the bottom.

Turn a knob: drag it or tap either side of it, roll the wheel over it or use the arrow keys; a double click puts it back. DOWN is a button: hold it down and the thing takes them under. The patches step on by themselves until you touch anything.

A rack round BARRELS: a drum machine and a bass into DEEP; the barrels move the bass's filter, a pad's swell, the hats' pan and how far the whole mix sinks. Listen plays the patch from its top.

example patches

The barrels, the sea, the pull and every out and light here are BARRELS's engine, the module's own code, running in your browser. The drums, the bass and the rest are a stand-in rack.

Something's down there

Three barrels are on lines into the thing, each listening its own way, and each one floats: buoyancy, weight, drag, a line that pulls only when it's taut, and a sea under it. So they don't follow the sound, they ride it.

DEEP: audio in, anything: a kick, a bass line, the whole mix. It isn't passed through.
The barrels: each lights from the top as far as it rides over the calm sea, goes dark under the water and flashes as it bursts back up. The waterline glimmers with the swell and goes dark while they're under.

The barrels and the sea

WEIGHT: fully left the barrels are light: they ride high, bob quickly and burst clear of the water. Fully right they're heavy: they ride low, the everyday pull hardly moves them, and after a dive they come back up one at a time over seconds.
LINE: fully left the lines are tight and every pull is straight down. Fully right they're slack and stretchy and pulled twice as far: every pull comes late, snatches the line taut and bounces the barrel on it.
SWELL: fully left a flat calm, so with nothing in DEEP nothing moves. Turned up, a swell rolls under them from left to right; fully right a heavy sea with a chop of its own throws them about, crests washing over them.

Going under

Three barrels can hold it up, and an ordinary pull can't keep one under. When it dives, they all go.

DIVE: how readily it goes down. Fully left never; at noon on a big surge of the lows, a drop after a breakdown or a hit out of quiet; fully right on every hit, as soon as they're back up.
DOWN, a lit button and its gate: hold either and the thing takes them under for as long as it's held. The cap glows while it pulls.
WEIGHT, LINE, SWELL, DIVE, the CV jacks: each added to its knob, 5 V half its travel.

What comes out

HEAD: the barrel on the short line to its head, listening to the lows: it ducks on the kick and springs back with a bounce.
BACK: the cask on the long line to its back: it sinks with the weight of the lows and lags behind them.
TAIL: the keg on its tail, listening to the highs: it jitters.
Each is its barrel's height: 5 V afloat on a calm sea, about 0 V at the bottom of a dive, up to 8 V thrown clear.
UNDER: high while it has all three under.
SPLASH: a trigger as each one bursts back up through the surface; after a dive, three in a row.

Inside

One board sits 10 mm behind the panel with everything on its front: the jacks, the knobs, DOWN's button, the 52 LEDs and the whole circuit, the USB-C in a notch in its left edge. Each band of a barrel has two white LEDs in its own cell of a black printed baffle, so a barrel lights band by band from the top; each dash of the waterline has one. An RP2350 listens to DEEP and runs the sea and the barrels on one core.

The BARRELS panel riding a groove: the head's barrel ducked, the cask lower, the keg riding high, the waterline lit, its knobs and button on.

Drag it or use the arrow keys to turn it; click it to take it apart.

Specs

Format

Width: 20 HP
Depth: 20.8 mm behind the panel
+12 V: about 45 mA dark, 170 mA in play, 200 mA with light barrels, 245 mA at the most (estimated)
−12 V: about 5 mA (estimated)
+5 V: not used
Controls: a big knob, 3 knobs, a lit button

I/O

DEEP: audio in, 24-bit; ±9 V reaches the converter unclipped; never passed through
DOWN: gate, held while high, past about 0.9 V; safe to ±12 V
CVs in: WEIGHT, LINE, SWELL, DIVE: added to the knobs, 5 V half the travel; −5 to +5 V, safe to ±12 V
CVs out: HEAD, BACK, TAIL: 0 to 8 V, 16-bit, each barrel's height; 5 V afloat on a calm sea
UNDER: gate, 0/5 V, while all three are under
SPLASH: trigger, 0/5 V, 10 ms, as each one surfaces

Engine

Brain: RP2350, one core, at 46.875 kHz, 32-bit float; the barrels 4,000 steps a second
Light: 31 windows, 52 white LEDs, 100 frames a second
Power cycle: the barrels wake at rest on a calm sea; only the calibration is kept