PretentiousFood

When I tried one of their IEMs, the tip came off inside my ear and the sales clerk had to use the TRS jack to pry it out. Not recommended.

Got it, thanks! It's running without the servo now, just need to finish up the power supply and box it up.

I know this thread's well past its prime but I finally put mine together and I think there's an error on the board. You need to mount the 2N4393 from the bottom of the board or twist the leads for the pinout to match the TO-18 part. It's running fine now though. This is on the boards with the onboard heat sinks. Haven't had much luck with the servo though, and I notice it doesn't match the schematic, which uses a second op amp for inversion. The ouput doesn't drift more than maybe 10mV in the one I have running, any reason why I shouldn't skip the servo and connect the gain resistor (R3 or R17) directly to ground without the caps? E: the schematic, for reference.

I've had good luck using something like this, but you need to make sure the triode filaments come on before b+ or you'll exceed the VR tube's current rating for a short time. http://i.imgur.com/smuyUlc.png At this point they really aren't acting as much more than a pilot light and it's probably smarter to do something like the Heathkit supplies.

Just came to point out how amazing that schematic is. It really looks like they took a regular CRC filter and replaced a T of the filter with some underrated caps with glow tubes. Are those supposed to be voltage balancing resistors across the glow tubes? If anyone wants to upgrade this to parafeed, Edcors are $10 per transformer.