Just today I read in AudioXpress magazine an article about voltage quadruplers where that autor suggests can be used to get the recycled solid state PT suitable for the tube projects.
In theory sounds ok, not sure what the heck it would look like in practice.
Voltage Quadruplers aren't all that efficient, basically they consist of two "half-wave" voltage doublers, cinnected in series. They're OK for light current loads, but pretty much NG for power amp levels of current loading, as they tend to drop off rather rapidly with increasing current demand. The PS tranny needs 4X or greater of the expected delivered DC HV current.
Sometimes these were used with direct AC line voltage. NOT a good idea... This always delivers a HOT chassis
The basics of voltage doubling and quadrupling can be found here:
http://www.nmu.edu/www-sam/tlac/spotlig ... pliers.pdf
and a few more ideas here: http://www.voltagemultipliers.com/html/multcircuit.html
And if you're into some serious arcs and sparks, check ouut this Cockcroft-Walton HV multiplier:
http://members.tm.net/lapointe/Cockcroft_Walton.htm
Back to the real world, the full wave voltage doubler is a tried and true performer, and with SS rectification and hefty electrolytics, it's a good way to get usable B+ voltages out of isolation and other low voltage (100-150 VAC) power trannies.
Remember that the primary current capability has to be at least twice (three X is better) that odf the delivered DC B+.
HTH
/ed B in NH