crush depth by daylight noise

The dive

Both sides are squeezed together, so the stereo picture holds. The gauge round DEPTH is the squeeze as it happens: the needle a lit segment, 30 dB across, the travel behind it glowing faintly.

DEPTH, the big knob: how deep it dives. Fully left is the surface, and the sound comes out exactly as it went in. Turned up, the squeeze starts lower and grips harder, and the quiet parts are brought up behind it: glued at noon, a roaring slab at full.

DIVE: how fast the squeeze moves. Fully left a slow glide; fully right a crash dive that grabs in a tenth of a millisecond, lets go in thirty and pumps the whole mix.

DEPTH and DIVE, the jacks: their CVs, added to the knobs.

The hull

Every hull has a line: the squeeze it was built to take, a lit segment on the gauge. Short of it the hull is silent. Past it the gauge lights red, the needle trembles, and the further past, the worse it gets: the steel creaks and groans, pitched by the hull and bent by the squeeze; the hits that push against the squeeze shoot rivets out, and past a few decibels they go by themselves; water sprays in where each went; now and then the hull buckles.

HULL: how old the boat is. Fully left a new boat, its line deep down the gauge; turned up the line comes up and the steel loosens and drops in pitch; fully right an old boat whose line is at the surface, so it creaks and pops rivets even in the shallows.

HULL, the jack: its CV.

The rivets: the ring round the gauge. Each one that goes flashes where it was, then glows like a leak until the water drains; you hear it from that side.

Charges and the surface

CHARGE, a lit button and its trigger: a depth charge goes off near the hull, nearer or further each time. Its wave slams the squeeze down and lets go over a third of a second, a deep boom under it, every light flickers, and if it takes the hull past its line, rivets go. Patch the kick for a slam on every one.

SURFACE, a lit button and its gate: blow the tanks. The squeeze lets go at once, smoothly, with a roar of air and a burst of bubbles, and the sound is up in the open, untouched. Held, it stays up; let go and it dives again at DIVE's speed, the hull groaning as the pressure comes back.

What comes out

PORT, STARBOARD: the squeezed sound, with the hull's: the rivets and the water where they went, the groans across, the booms in the middle, the roar wide.

PRESSURE: the squeeze as a voltage, 0 to 8 V across the gauge, so the rest of the rack can feel the dive.

RIVETS: a trigger for every rivet that goes.

Inside

One board sits 10 mm behind the panel with everything on its front: the jacks, the knobs, both buttons, the 90 LEDs and the whole circuit, the USB-C in a notch in its top edge. Each gauge segment has a white LED and a red one in its own cell of a black printed baffle, so the needle reads segment by segment and the gauge turns red past the hull's line; each rivet has a white one. An RP2350 squeezes the sound on one core and lets the rivets go on the other.

The CRUSH DEPTH panel at crush depth: the gauge round the big DEPTH knob lit red past the hull's line, rivets lit round it, its knobs and buttons 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 67 mA dark, 90 mA in usual play, 200 mA at crush depth, 215 mA at the most (estimated)
−12 V: about 4 mA (estimated)
+5 V: not used
Controls: a big knob, 2 knobs, 2 lit buttons

I/O

PORT, STARBOARD in: audio, 24-bit; ±10 V reaches the converter unclipped; STARBOARD takes PORT when it's empty
CVs: DEPTH, HULL, DIVE: added to the knobs, 5 V the whole way; −5 to +5 V, safe to ±12 V
CHARGE, SURFACE: trigger and gate, high past about 0.9 V; safe to ±12 V
PORT, STARBOARD out: audio, 24-bit, exact to ±7.5 V, a soft knee that never passes 8.75 V; about 3.5 ms in to out
PRESSURE: CV, 0 to 8 V across the gauge's 30 dB, 16-bit
RIVETS: trigger, 0/5 V, 10 ms

Engine

Brain: RP2350, both cores, at 46.875 kHz, 32-bit float
Light: 63 windows, 90 LEDs: a white under each, a red beside each gauge segment's; 200 frames a second
Power cycle: it wakes at the bottom, its hull new; only the calibration is kept