String Spectrum - no text

One winter’s night in 1979, in my electronics lab in a country house overlooking a racehorse exercise track deep in the country east of Toronto…

The Instant of Invention

I was experimenting with an unusual drive circuit for a sustain system. Conventionally, a string sustain system has two elements, a sensor ‘pickup’ and a driver. The string is driven by an electromagnet at one position while its vibration is sensed by a second electromagnet located at a different position along the string’s length. The problem with this arrangement is, information about the system behavior must pass along the unpredictable warp of the string. It’s like trying to draw a perfect circle while looking into a fun-house mirror. I realized this could be greatly improved by using the same electromagnet for both sensing and actuating the string. Doing both things at exactly the same location, there would be no distortion in the information flow of the system, therefore you could achieve perfect control of vibration. But sensing and actuating in the same place, that’s the tricky part!

I stood with a guitar next to a ridiculously huge hand-wired mess of a circuit that covered an entire table top.  I powered the system up. Incredibly it worked right away.  That first chord just hung there, all strings beautifully sustaining.  Then I flipped the master phase switch to ‘damp’ and all six strings immediately stopped vibrating as though they’d been hand-muted.

This meant that in principle a musical instrument string’s behavior could now be electronically shaped to vibrate with almost any desired timbre. All that remained was to do the math and the engineering needed to turn this realization into a musical instrument.

Accomplishing this was to take 25 more years.

It was 1981. I couldn’t see any viable way to turn this invention into a practical system for guitarists. Some of the electronic components didn’t even exist yet in the right form. Many of the components were too physically large and inefficient to be practical in a musical instrument. Clearly the idea was ahead of its time.  It was also too early to patent this invention. Patents last only about 20 years. Well-kept secrets can last much longer.

So I obtained a confidential notarized and dated ‘proof of invention’ from a Toronto patent firm. Then I just stuffed it all back inside my head and went on with life.