[laughs] The "Ion Cloud" loudspeaker was another one of those ideas that had kicked around, and the day came when I decided that there was no reason not to build it. As you can see from the photos on the cover of Stereophile and elsewhere, it looked like a large barbecue grill. It had no moving parts and its construction was a grid of wires. We applied some very high voltages to what were, essentially, the tungsten filaments used in photocopy machines. It was really a push-pull electrostat that used ionized gas instead of a diaphragm. And it worked reasonably well. It took several kilowatts to get any sound out of it, but it was the most physically and sonically transparent loudspeaker I've ever run across. That is to say, you could see right through it, and it sounded like it wasn't there. It was quite remarkable in that regard.
We were feeding it with an Ampex tape deck running into our Threshold Model 4000 power amplifier, then driving the loudspeaker through a step-up transformer. It drew so much power at the display at CES that every time there was a loud passage or a transient, the AC line would drop. The tension arms on the tape deck would go slack, the sound would stop, the power would go back up, and it would start again; then the power would go, and it went into an oscillatory loop which included every element of the chain, including the AC line and the tensioning arms on the tape deck. We had a lot of fun doing that—a good demonstration of how much power it required. Fabulous device, but it put out ozone, and after some extensive exposure to the ozone I found myself lacking oxygen in my bloodstream...It was a year before I could go near a copy machine.
