planchette: 20 HP, a sequencer that seems to move on its own, by daylight noise

The hands

The planchette is where the glow is: the letter under it burns near white, its neighbours amber. Whatever comes in at the two hands pushes it, and the pushes add up over time, so a jitter grows into a slow, deliberate-looking drift. It slows on the letters as it passes, and now and then stops on one.

LEFT HAND: its movement pushes the planchette across the board. A slow LFO sways it; audio or noise shakes it. Unpatched, it's an unsteady hand of its own.

RIGHT HAND: the same, up and down the board.

PULL: how hard the letters hold it, from a smooth glide over them to a lurch from letter to letter, stopping on each.

DRAG: how slow it goes, from a crawl, a letter every ten seconds or so, to a dash of several a second.

The spirit

Turn SPIRIT up and something takes hold of it. It steers from letter to letter, circling in and resting on each, and spells a word; the letters fade behind it slowly enough to read. Then it wanders a while before the next. Now and then, between words, it answers YES or NO. At the top it hurries, word after word, and before long slides to GOODBYE on its own.

SPIRIT: down, nothing steers it and it lands where chance leaves it. From about ten o'clock it spells, with less wandering between words the further up it goes.

SPIRIT CV: ±5 V adds or takes away half the knob.

What the board says

Every letter is a note: A to Z climb a minor scale from 0 V, a little over three and a half octaves, and the numbers are the root in whole octaves, 1 the lowest. Where it rests, the note is exact; between letters it steps, or with PULL down it slides.

LETTER: the letter it rests on, 1 V an octave, 0 to 8 V.

GATE: high from the moment it lands on a letter or a number until it moves off.

X and Y: where it is, 0 to 8 V across and up the board.

YES and NO: high while it rests on them.

Goodbye

When it slides to GOODBYE the sitting is over. Every output holds where it is and the board goes dark but the word, and nothing moves until it's summoned again.

GOODBYE: high from then until SUMMON.

SUMMON: the button glows while the sitting is over. Press it, or send its jack a trigger, and a new sitting starts with the planchette in the middle of the board.

The panel

Twenty HP, every part on the line's staggered grid and mirrored about the middle. The board takes the top half: the letters in two arcs, the numbers in a row under them, YES and NO in the top corners over their outputs and GOODBYE at the foot over its own. Each is a window of circuit board lit from behind, 41 LEDs in all. The art is gold smoke.

YES and NO at the top corners, then the board.

SPIRIT in the middle with PULL and DRAG either side, LEFT HAND and RIGHT HAND under them.

SUMMON's button on the middle, its jack and SPIRIT CV down the edges, X and Y under the hands.

LETTER and GATE at the bottom corners, GOODBYE at the foot.