One very important Part of a Tube Amplifier is the Power Supply. It is crucial for the quality of the whole system. Especially beginners encounter problems like Hum or Drift that can become quite annoying. But resue is ahead: The following circuit uses a modern Mosfet to deliver a stable and virtually Hum-free voltage to power a large number of Tube (and others of course) Projects. I use this PSU for an OTL Headphone-Amplifier and two EL84 Power Amps.