drawn

draw the patch

20 HP

A matrix mixer you patch with a pencil. Graphite conducts, so a line drawn across a box joins that row to that column, and how dark it is sets how loud. Rub it out and it's gone. Pull the cables and draw a loop, and it sings.

The DRAWN panel: black, gold swipes all over it, and in the middle a black card with sixteen small windows of bare board in four rows and four columns, a gold rail over each row and a gold bar under each window. Eight jacks down the sides, a jack over the card, PITCH under it, four GAIN knobs and a big SLOW knob at the foot.

Draw on the card: a line from a gold rail to the bar under it joins them, and every pass adds. A tap in a box is a whole stroke. Or tab to a box: up and right draw, down and left rub. 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. The patches step on by themselves until you touch anything.

Four dark parts wait in the rack. Listen plays the patch from its top, on a fresh card.

example patches

Everything here runs in your browser. The module has no code in it, so this is a model of its circuit, and of pencil on board from measurements of pencil on paper. A real line will be its own. The rack is a stand-in.

The card

Sixteen boxes of bare board, four rows by four columns. Row A's rail runs along the top of its boxes; the gold bar under the third box is column 3. Draw across box A3 and A goes to 3. The line's a real resistor, so it's a real fader, and audio and CV go through alike, DC and all.

The card lifts out. Draw one at a desk, keep a stack, swap a patch in a second, post one to a friend.

The pencil: a soft one. One light pass may not join at all. Go over it and it comes in. Two lines side by side are twice as loud as one.
The rubber is a mute, or a fader going down. It leaves a ghost.
A thumb smears a line and bridges a gap while it's there. On the gold it adds the room's hum.
A faint line is a dirty line: it crackles, and the quietest of a sound falls through it.

Four into four

A, B, C, D: the four rows, audio or CV.
GAIN 1 to 4: what a line in that column is worth. At noon a line gone over four times is about unity. Fully left a dark box is. Fully right a faint line is, and anything darker hits the rails.
The windows glow with what's coming out of their column. A line is silver on a dark window and black on a bright one, so a drawing turns over as the sound comes through it.

A row with no cable

A row with no cable hears its own column: A hears 1, B 2, C 3, D 4. Every box is then a wire from one column to another, and every column turns what it's given upside down. So the shape of the drawing is what it does.

One line on the diagonal (A1, B2, C3, D4): a column holding itself back.
Two lines facing (A2, B1): each holds the other down, one stuck high, one low: a bit of memory. A hit down a darker line flips it.
Three round a loop (A2, B3, C1): it can't settle, so it sings, one note a third of a cycle apart on three outs. Dark lines are high, light ones low. GAIN is whether it sings at all. Rub a line too thin and it stops.
Four round a loop (A2, B3, C4, D1): it stands still. Most drawings do. A loop has to be meant.

SLOW

SLOW, the big knob: the whole drawing's time scale, thirteen octaves of it. Fully left it's a plain mixer. Turned up, every column closes down together, and a loop falls from a whistle through a bass note to a slow breath. At full, only a slow swell gets through.
PITCH, 1 V/oct: moves SLOW, so a sequencer can play what you've drawn. Rough, as pencil is.

What comes out

1, 2, 3, 4: the four columns.
SUM: every column with no cable in it, added. Past the rails it clips.

Specs

Format

Width: 20 HP
Controls: 1 big knob, 4 knobs, a card of 16 boxes, a pencil, a rubber

Inputs

A, B, C, D: audio or CV, DC coupled, ±10 V. With no cable, the row hears its own column
PITCH: 1 V/oct, on SLOW

Outputs

1, 2, 3, 4: audio or CV, DC coupled, to about ±10 V
SUM: the columns with no cable in them