Version 1

(original version)

The electromagnets:
Magnetic Sensor Systems (
E-66-75 Tubular Electromagnet
AWG 30 (8.4 ohms), infinite duty cycle
-Permanent magnets:
The Magnet Source
Ceramic Magnet Blocks
Part #07001

Rack and suspension system:
Assembled entirely from equipment purchased at the hardware store.


Wood bar: a 2×4, 48 inches long
Track: a bi-fold door track with sliders. The sliders, to which a door would normally be attached, worked nicely to allow the electromagnets to be positioned at any point over the width of the piano.
Metal brackets: about 4 inches long.
The bolt is held in place on the bracket by two opposing wingnuts, one on top of bracket, the other the bottom. The height of the electromagnet is adjusted with these wingnuts.

Amplifier system:
12 Vellman, Inc. 7W mono audio amplifiers (Mfg# K4001)

Audio interface: Motu Traveler (8 analog out plus 8 ADAT optical out)
connected via lightpipe to: Behringer Ultragain Pro-8 Digital ADA8000