Electronic

Drum Kit

March to the beat of a very different drum.

Velocity-sensitive impact sensors in PVC pipes interface to a micro drum machine. By Tom Zimmerman

An electronic drum is basically a switch that triggers the playback of a digitally recorded drum. Here’s how I built tubular drum controllers out of PVC pipe and connected them to a studio drum machine to create a professional-sounding electronic drum kit.

Each controller has a guitar string suspended so a pulse-stretching circuit lengthens the signal, above 4 strips of aluminum tape. When you strike by charging a capacitor. the string with a drumstick, it touches the tape Two male-to-female serial cables let you unplug and closes a circuit to trigger the corresponding the controllers from the drum machine. I cut the sound from the drum machine. Foam covering the cables in half and connected them to the controllers pipe softens the blow and provides a nice bounce. and the drum machine. To plug-and-play, you simply Underneath each controller, a pressure-sensitive mate each connector to its former other half. piezoelectric device lifted out of the drum machine detects the force of the hit, to determine the relative volume.

Tom Zimmerman is a member of the User Sciences &

^{The brief contact between the struck string and} Experiences Research laboratory at IBM’s Almaden Research the foil is too short for the drum machine to detect, Center. An MI T graduate, he was profiled in MAKE, Volume 04.

Photograph by Sam Murphy

88 Make: Volume 15