A column devoted to answering your questions about PAIA, electronic music or any other area which might be of interest to our readers.

Dear PAIA,

Kraftwerk (the group that recorded the song "Autobahn") has a machine that produces a synthesizer sound, but it's total configuration is the farthest thing from an average keyboard controlled synthesizer. It consists of an array of rings and plates, and when the performer wants to make a sound, he touches the rings and plates with a metal rod. I want to know if this is anything like the old-fashioned Martinot or Ondioline, and if I could do something similar with PAIA equipment. Not that they had any sounds that a PAIA synthesizer could not produce, but they had such a far-out appearance that I would like to construct one.
Lionel Cassin, Brooklyn, CT

Lionel,
The apparatus you saw Kraftwerk using is a trigger source for percussion sounds.

I suspect they made the setup themselves, as they have built and modified much of the equipment they use. The metal rods the performer holds are used much like drumsticks, and have a DC trigger voltage applied to them. The array of rings and metal plates are connected to the trigger inputs of several envelope generators, sequencers, and so on. Each different trigger pad has a different patch associated with it. Thus, the percussion player can select the type of sound he wants, and trigger it at the proper time by hitting the pad with one of the drumsticks. The voltage applied by the drumstick initiates the sound in the same manner as the keyboard trigger output would work if keyboard control were being used.

A unit could easily be made that would work as theirs does. Metal tubing, rods, and plates are commonly found in hardware stores, or you may be able to find what you need in someone's junk pile or garage. A five to nine volt DC level can be applied to the sticks from a power supply or bias supply on the synthesizer. Be sure to insulate the sticks where they will be held. This will eliminate the 60 cycle hum from the performer's body, which would be superimposed on the control voltage causing possible mistriggers and so on. The trigger plates are wired to the trigger inputs of particular modules you wish to control. Shielded cable should be used with the shield being grounded at the synthesizer end but no connection at the trigger plate end. The plates can be mounted individually on old music stands, or microphone stands. If this is done, the plate should be insulated from the stand by mounting on a piece of plastic or wood, and then mounting the insulator to the stand. As I recall, Kraftwerk has all trigger plates mounted in a fixed configuration on one big fold-up stand. This would make it easier for setup at a job site, but would lack the versatility of a modular system.

I hope this spurs your creativity, Lionel. If you, or any of our other readers, DO build a setup such as this, PLEASE send us a picture of it (B & W glossy, of course) so we can print it in Polyphony.

Marvin Jones