I actually found a couple hours to work on my ES headphone project yesterday. I used my Dremel to rough cut a pair of 2 5/8" stators out of a sheet of scrap perferated steel. I built a little jig that let me grind them round and to size using a disk sander. Plumbing gaskets (a little too thick) and 0.7mil drop cloth completed the BOM. I tensioned the diaphram using celophane tape on a sheet of glass--just tight enough to get the wrinkles out. Radio Shack provided the copper PCB tape for the diaphram contact. I used powdered graphite to produce a very consistent charcoal-colored coating, then cleaned most of it off with Isopropyl. If you can see the photos of my makeshift breadboard, the toroidal transformers are just 30:1, I used one for the 550VDC supply as well. I used two of them to fake a center tap in the secondary. When I powered up the setup I though something was wrong... dead silence. No snapping, no crackling, no crinkling, no hissing, no whirring. I hit "PLAY" and was stunned to hear music coming out of the "panel". I put my ear as close as I dared... Let's just say I am anxious to find time to build the second element and then the frames and headband. Total build time... three hours, not including gathering materials. Fun.