The initial build went very well, and after a few teething pains (see below), it works great, with big streamers (~20") and it is very loud! I have had no failures during several hours of operation, and it's been a real hit with everyone who has seen it. Here are a few observations:
When testing the low-voltage control circuitry, I never heard any "buzzing" from the drive circuitry - it's probably my hearing. Since the scope traces looked like the pictures in the manual, I kept plugging along.
I had some initial problems that were causing the interrupter to lock up after ~30 seconds. Shielding the MIDI cable and control box with aluminum foil, and moving it and the computer as far away as the fiber would allow solved the noise problem. I'll eventually get a better MIDI/USB cable.
I was a bit too neat when varnishing the secondary with a spray can, so I did have a few arcs. Slathering on another 3 coats of varnish with a brush, removing the primary spacers, and taping the primary solved that problem.
For the ground plane, I am using three sheets of Al foil, clipped together at their ends with large paper clips. It is attached to the coil by an alligator clip lead soldered to the central grounding point on the back of the 120V input socket.
The only time I wiped out any components was by plugging the low-voltage supply's output into the PC board when the wall wart was unplugged (for over 24 hrs!). It drew a large spark, and the blue and red LEDs flashed briefly as the two voltage regulators died. I now make sure that the wall wart is grounded by plugging it in to a plugged in switched outlet strip. It hasn't happened again.
The final thing has to do with improving the mechanical design of the way the secondary transformer attaches to its ends. I've broken it twice during moves - it seems that epoxy doesn't like the PVC the secondary is wound on.
Anyway, it's a great kit, and has been a lot of fun to build. Now I just have to learn how to edit MIDI files...
Jim
