400v Switch Mode PSU

[defaced]

Um... that would make about 560v B+ and 400 watt capability. Isn't that a trifle large for a three-tube preamp? Includes heaters?

What I was saying in response to Gregg's post (quote below) is that I wouldn't want to run an entire amp off of a switcher because I can get transformers that are big enough and cheap enough for what I want. And thanks for those links from Allied. I didn't think to look there, but the 227-0001 has some definite potential.

It's possible to build a SMPS that will power up the whole amp but a well designed SMSP (and that's definately not for everyone) that will provide the necessary voltage and current may cost you more in terms of time and money spent.

[Enzo]

The Allied thing was because I have used their transformers in the past with good results at reasonable cost.

But another option is a commercial amp part. For example the PT from a Peavey Rockmaster preamp. Their prices tend to be reasonable, that tranny makes useful B+ and has heater current for four 12AX7s, and fits in a 1-space chassis.

The Fender Tube Reverb re-issue has a nice littel PT. Makes 6v and has B+ winding that makes 294v.