Vactrol Cyanbox

Suss Müsik designed and built a weird instrument called the Vactrol Cyanbox. You’re obviously wondering what it does.

Cyanbox

Inside the box are two vactrols. What’s a vactrol? It’s another term for a photoresistive opto-isolator, which is an exceedingly fancy term to mean “a light that blinks into a sensor and turns something on and off.” The word vactrol is derived from a trademark by Vactec, Inc. Now you know.

So there are two vactrols, each a single white LED directly facing a photocell resistor and encased in a black rubber tube. Each vactrol controls its own voltage-controlled oscillator (VCO).

One VCO plays a continuous tone. The pitch is controlled by the rate at which the LED blinks, adjustable by two knobs with a single 1/4″ output. The other VCO can also play continuously or be controlled via pushbutton, with added knobs for pitch, modulation and density.

In the video below, a third (!) vactrol distorts the playback of a hacked cassette Walkman. Not shown are two Moog pedals that control filtration and a prerecorded glitch loop played via an offscreen iPad.

Yet to be announced: some live* (!!) Suss Müsik performances!

*Well, sort of live.

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