SMPS for Valve amplifier

[btbass]

Has anyone made a switched mode power supply to power a ~50 Watt valve amp?
Would need about 400 volts output at a couple of hundred milliamps.

There was a silicon chip article on modifying a pc power supply for valve amps, but I can't find it.

Peavey have just released a 300 Watt Bass amplifier with a SMPS. This brings the weight down to 37lb.

 

[FvM]

SMPS are manufactured with different output voltage levels, also e.g. 400V.

The best way to modify an existing low voltage output SMPS design is by rewinding the transformer secondary, add a suitable rectifier and capacitor and change the feedback divider. If you want to keep the original transformer, you would need a cascade rectifier with a rather large multiply factor.