I wanted to mention that a few folks have been having issues with the power supply not supplying enough current on the -500V rail. Seems like setting the 30 ohm resistors to 20 ohms helps. The behavior is that if just one channel (either side) is connected then everything works perfectly, but if you connect both sides, then the rail sags and it's impossible to adjust the batteries correctly. If you're not having the issue, there is no reason to do this. I'm not sure if the amp is drawing a bit more or the current sources are providing a bit less than needed. In other news, I just got my PS together. I need to mount transistors to heatsinks, which I'll be working on today. I did test the relay driver and found a small issue for the LED output, but it was easily solved. I've got it mounted in a jig so I can easily solder the remaining transistors from the bottom. Here's some shots EDIT: I just wanted to add that I love working with the SMD parts and heat gun. I'd say I can move about four times faster when stuffing components.