No-input mixing & feedback instruments

This module builds toward one whole task: turning a piece of routing hardware — a cheap, preferably old and noisy mixer, or a matrix/Benjolin circuit — into a self-oscillating instrument, and committing a single unrepeatable improvisation to tape. This is the practice of experimental noise and EAI (electroacoustic improvisation) sets, where the performer arrives with no sequencer, no laptop, and no safety net: the feedback loop itself is the instrument, and the recorder must be rolling because no fader position can ever be recreated.

The arc starts supported. First internalise why routing outputs back into inputs makes a mixer sing at all — the no-input mixing concept — then follow the setup procedure (“patches outputs back to inputs and records live because settings are unrepeatable”) as a just-in-time recipe for your first loop, minding the level warnings. Drill the sensitive gain-and-EQ moves until finding a tone, losing it, and finding it again is reflexive. Then widen the palette: the matrix-mixer atom shows how a grid of feedback pots becomes a many-parameter instrument in the Tudor lineage, and the Benjolin atom offers the self-playing alternative, where chaos is endogenous rather than hand-steered. The capstone requires both — first the plain mixer self-patch, then a reconfiguration as a matrix or Benjolin-style rig — so that all three objectives are jointly evidenced in a single take. Nakamura’s practice of treating the mixer as an equal partner frames the capstone’s reflection: you are not dictating an outcome but obeying what the system offers.

The five required atoms gate the capstone directly — without them you can neither build the loop, navigate its stable and unstable states, nor articulate the surrender the take demands. The supporting atoms enrich: constraint-as-catalyst reframes the poverty of controls as a gift, random-voltage modulation suggests hybrid extensions, and process-music thinking situates audible system behaviour in a longer tradition.

Runnable examples

Generated from the context/ instrument corpus by concept (redistributable idioms only). Do not edit — regenerate with gen-module-examples.mjs.

feedback-loop

{ CombN.ar(Impulse.ar(2) * 0.3, 0.2, 0.2, 3) }.play

_{supercollider-0015 · CC0}

s("cp").delay(0.5).delaytime(0.166).delayfeedback(0.7)

_{strudel-0018 · CC0}