A Multi-Voiced Theremin

John Rigg has taken the idea of the simple theremin to a new height. His versatile multi-voiced theremin, shown to the right, is capable of producing up to 12 tones at once! The unique design seems to have been inspired by the mad scientist-style inventions from popular 50's and 60's Sci-Fi movies.

The switches on front panel allow the theremin to be used by either left or right-handed players. Each of the two brass antennas can control either pitch or volume. The two rows of knobs below the antennas vary the tone produced by the unit. Each side of the instrument can produce sinusoidal or square wave tones in the fundamental, one octave higher, one octave lower, a third, and a fifth. By turning up the volume on different knobs, the instrument can play major chords. The VU meters on the front panel show the overall volume level coming from each antenna.

John uses a standard VCA IC for the volume control. The capacitive density circuit is a digital PWM circuit that has an analog voltage output that can control any voltage control devices. The volume circuit increases in volume as your hand gets closer to the antenna. As John says, "...it just does not make sense to do it any other way. I mean you always touch or hit something to produce a sound. You do not move away to produce a sound."

John's garage in Auburn, Washington is home to a colection of over 1500 robots, big and small, professional and toy, working and still. He also builds life-sized replicas of famous Sci-Fi robots. His collection also includes a fiberglass Gort (The Day the Earth Stood Still) with moving visor and death-ray, and "Robot" (Lost in Space).

You can view John's other project at his excellent website. -JBB