106 Nicolas Collins
Matrices
David Tudor, one of the pioneers in the field of live electronic music, used
matrices of relatively simple or common circuits to produce sound of great
richness and variation. Instead of simply mixing a handful of sound sources
down to a stereo signal, Tudor built up arrays of modules with multiple
feedback paths and output channels. The recent rise of the “no input mixing”
school of internal machine feedback has exposed a new generation of musicians
and listeners to the possibilities of matrix feedback.
You can set-up matrices with nothing more than patchcords and clip leads, but
the 3 x 3 matrix mixer shown below lets you adjust levels more easily.
You can expand this circuit with as many pots as you can afford.
Connect a few circuits, including both sound generating circuits, such as your
oscillators or toys, and some processing circuits, such as a photocell panner, a
fuzztone or an echo pedal. Send one output of the matrix to an amplifier for
listening, and the others can be sent to the inputs of your circuits. By adjusting
the levels of the various pots you can create a pretty straightforward signal path
(toy through fuzz to speaker) or a more devious one (toy through fuzz to
speaker, fuzz also to delay which goes both to speaker and back into its own
input.)