Not wanting to spend the money on a dedicated power supply ... The ATX supply [C] used could supply 25 amps on the 12 volt rail, more than enough for a simple RepRap. There was only one problem ...

It’s not entirely clear why [Advanced Tinkering] needs a 50,000-volt power supply, but given the amount of work he put into this one, we’re going to guess it will be something interesting.