sentinel

it hangs there

20 HP

A real chrome ball in an open window, nothing touching it, and its height is your CV. It doesn't follow you: it swings, overshoots and settles, as a real thing does. Push it too far and it falls, you hear it land, and everything it was moving goes with it.

The SENTINEL panel: black, a shaft of light in gold dots falling down a stone wall to a round-headed window on the spine, and down the middle of it a thin gold line from a ring under the name, which stops, cut, just above the window. LIFT and KICK, a lit button and a black one, at the top with their jacks, GRIP and RING, WEIGHT and DRAUGHT down the sides, PASS and FELL beside the window, HEIGHT and SPEED under them, WARD and POSITION's jack, KEPT and CLATTER in the bottom corners, the big POSITION knob at the foot. sentinel at the top, daylight noise at the bottom.

The ball: there's no glass, so put your pointer or a finger on it. Hold it, drag it, let go and it flicks. Knock it out of the air. Lift it out of its cup, let go, and it stays. On a keyboard, tab to it and use the arrow keys, Shift to knock it out, Enter to throw it. 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. LIFT and KICK are buttons. The patches step on by themselves until you touch anything.

A bass, a pad and drums in F minor at 122 BPM round SENTINEL. Listen plays the patch from its top.

example patches

Everything SENTINEL does here is its engine as designed, running in your browser: a model of the ball, and the loop that holds it. Your pointer stands in for your finger, and the rack round it is a stand-in.

It hangs there

A coil overhead pulls, a sensor under the floor reads the height four thousand times a second, and the loop between them holds a chrome ball in the air. Nothing touches it. There's no glass, so nothing stops you touching it either. Hold it and the coil pulls against your finger. Lift it from its cup, let go, and it stays.

POSITION, the big knob, and its jack: where it's asked to hang, the band of light in the window. At noon the magnet does nearly all the lifting. Further out the coil works, and warms, and can only hold it so long. At the very ends it can't hold at all.
GRIP and its jack: the spring it hangs on. Fully right it's held tight and quick. Down near the bottom nothing much holds it: it hunts, it trembles, and it goes.
WEIGHT: how heavy it feels. Fully right it swings wide and slow, under a hertz, and it's a long way back.

How it moves

It's a real thing with a real weight, so it can't jump: ask it to move and it swings up, goes past, comes back and settles. It has a tempo of its own, about 2 Hz at noon, and you set it. Kick it near that tempo and each kick catches it on the way back.

KICK, the black button, and its gate: the coil lets go for a moment, as long as the hit is big, and it drops. A sphere can't be pushed down, only let go of. A negative hit pulls it up.
RING and its jack: fully left it's dead, a dip and back. Noon rings for a couple of seconds. At 3 o'clock it swings by itself for ever, a real weight being a real LFO. Further and every swing is bigger than the last.
DRAUGHT: a slow push of no one's making, so it moves with nothing patched. Fully right it's a gale.

When it goes

There's no timer and no dice. Up to a point the coil can stop it; past that point it's gone, and it lands in a brass cup at the foot of the window with a clatter you can hear in the room. HEIGHT goes to nothing, and whatever it was moving goes with it. Too near the coil and it goes the other way: it jumps up and clings to the ceiling.

LIFT, the lit button, and its gate: a second coil in the floor throws it up and the one overhead catches it in the air. Usually. The cap pulses while it's down. Held, it keeps throwing until it's caught. In the air it's a tug up. On the ceiling, LIFT or KICK lets it go.
The light is a band at the height it's asked for, so the ball gleams on its mark and goes dull off it. As the coil warms the light goes down.

Down, it's a drum

In the cup, KICK hops it. A harder hit hops it higher and it rattles for longer, real chrome on real brass. A piezo under the cup is CLATTER, straight to its jack, so every bounce is in your rack, and patched into a gate input each one fires it.

What comes out

HEIGHT: where it is. Nothing in the cup, 10 V on the ceiling, about 7 V at noon.
SPEED: how fast it's going, up or down: a quarter turn behind HEIGHT.
PASS: a trigger each time it comes up past its mark, so it clocks at its own swing.
FELL: a gate from the moment it's out of reach until it's caught.
WARD in and KEPT out: your sound, as loud as the ball is high. Kick it and the sound ducks, overshoots and rings. Let it fall and the sound's gone.
CLATTER: the ball in its cup.

Specs

Format

Width: 20 HP
Controls: a big knob, 4 knobs, a lit button, a black button, the ball

Inputs

WARD: audio, ±5 V
POSITION: CV, ±5 V half its travel, added to the knob
GRIP, RING: CV, added to their knobs, 10 V the whole way
KICK, LIFT: gates

Outputs

KEPT, CLATTER: audio, ±5 V
HEIGHT: CV, 0 to 10 V
SPEED: CV, ±5 V
PASS: trigger, 5 V
FELL: gate, 5 V