There were pictures of the internals of one of the 3 kV Power Designs high voltage supplies posted here on EEV Blog last year. Here are the insides of the HV-1556 6 kV model. Sort of the same thing just on a larger scale. Bigger paper-in-oil Sprague caps, bigger ceramic range switches, and the same type of encapsulated wire-wound precision resistors. The biggest difference is only a single Eimac 4-65 tube is used as the regulator. I had to replace a few e-caps to get it safe for power on, which thankfully was uneventful and everything works as it should. I put a new neon bulb in for the power indicator, and converted the funky output connectors (rear only) to standard binding posts.


-Mark-