Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => AmpTools/Tech Tips => Topic started by: Jennings on June 18, 2025, 11:17:57 am
-
Whilst toying with some random preamp and similar design ideas to make from old parts and bits, I realised maybe I should also consider building a versatile valve amp power supply. Something that could deliver HT, LT etc for tube amps and maybe old radio/hifi. Does anyone have any suggestions for circuits perhaps to use or base plans on? Or perhaps existing units worth a look?
-
kind of depends what you are trying to accomplish...
Start with the transformer, with a decent HT and current.
The Hammond 270hx ($123@HAwkusa) delivers 550vct @230ma.
You could implement several B+ terminals dropping 100v or so at each. If you use a pot (at appropriate power rating) then the voltage is variable at each terminal. 4-5 terminals should cover most designs.
Then consider the filaments
5v@3a would handle most rectifier tubes (270hx provides)
6v@6a would handle most amp designs including a 6v rectifier tube (270hx provides)
A switch from filaments supply to rectifier socket would allow 5/6v choice.
An Octal socket with a 9pin adapter would provide a lot of rectifier choices.
Might have to include a breadboard for most flexible rectifier pin outs
Maybe the forum has better or more clever approaches....