computer power supply to run tube radios

[Electronic M]

Better idea would be to get two 12V power transformers. Wire the 12V windings of the two together. Connect the 120V winding of one to the AC mains, and full wave rectify the other, and filter it with an appropriate capacitor. You can then use one or more LM317 or LM337 linear regulators in series and or parallel to reduce the voltage if it is too high (they can handle about a 45V input to output voltage difference IIRC). You can also full wave rectify the junction of the 12V windings of the transformers and use more of those regulators to get your filament voltage... It could probably be done for under 50$ to free depending on what you have in your junk box, and there should be no RFI emitted from it.