umbilical

UMBILICAL is a switched jack. With nothing in it, it reads low. With a cable in it, it reads high, even with the cable's other end hanging loose, so the cable itself is the mains: while it's in, the module runs clean, IN L/R straight through to OUT L/R. Pull it and the module is on its reserve.

Patch a gate into it instead and the gate is the mains: high, it runs clean; low, it's on its reserve. A clock makes it breathe, draining and filling in turn.

TIME is how long a full reserve lasts at a normal pace: 10 seconds to 10 minutes, 5:00 at noon. The pace follows how hard IN L/R are working, and the digits count down at it:

• STOP while the input is silent. Silence costs nothing.
• SLOW when it's quiet: half speed.
• NORMAL: the digits count real seconds.
• RACING when it's loud: five times as fast. A five-minute reserve lasts a minute flat out.

On the mains the pace is still shown, as a meter. Plug back in and the reserve refills in about three seconds, the digits running up, and the sound comes back with it. POWER is the reserve as a CV, 0 to 8 V.

SAG sets how the sound fails as the reserve runs down. At zero it's a plain fade. Turned up, the pitch sags, a granular shifter falling as far as an octave; a starved fuzz cuts in, sputtering and gating the way a dying battery does; and a low-pass closes over the top. Most of it happens in the last third: fine, fine, fine, then going.

At zero it dies. The outputs go silent, and ZERO goes high (+5 V) and stays high for as long as it's dead. SAG and BERSERK each have a CV in beside them: ±5 V adds or takes half the knob.

BERSERK is the chance, decided the moment it dies, that it comes back. At zero it never does; fully up, it always does. After a second to six of silence it returns on its own, roaring: louder, driven hard, the filter wide open, a little sharp.

The BERSERK gate is high while it rages, and POWER flickers between 5 and 8 V. It ignores the cable, and stops when it decides to, after 5 to 40 seconds, longer the higher BERSERK is. Then it's dead again, or charging if it's plugged in.

There's no display. The panel is a circuit board, and every word, outline, bar, stripe, segment and colon on the screen is a window: no copper and no solder mask on either side, just the glass-cloth board, which glows when the LEDs behind it light. Between the windows the copper stays on both faces under black mask, so a lit window can't leak into its neighbour through the board. Every segment of the six digits has its own window, its own LED and its own cell of a black printed baffle behind the panel.

On the mains, EXTERNAL lights and the digits are amber. On the reserve, INTERNAL and its stripes go red and the digits count down. Dead, it's dark but for a dim 00:00:00 and INTERNAL's stripes, pulsing slowly. Berserk, all of it is red, flickering hard (this page softens the flicker). How the light looks through the board is the one thing a drawing can't settle, so a small test panel comes first.

One board sits right behind the panel: the jacks, the pots and 69 RGB LEDs on its front, an RP2350 and the converters on its back. IN L/R go through a 24-bit converter 46,875 times a second, and the same engine that runs on this page runs there, the page's copy checked against it bit for bit. The LEDs have their own supply, and the firmware caps their current so the whole module stays inside its power budget.