So Many Questions ...

[Ratz]

Hi up there
this is my first post, but my interest about the forum date a year ago. Many times I found usual infos from passoinated peuples. Keep the good work, guis
I have two questions; so please discuss them.

A power amp, with transformerless PS may be dangerous. Getting a high voltages & high power demands a big transformer. But what about using an amplifier, with a rectifiers & caps, connected to the 120VAC, comming directly from a generator. I think that this is a closed AC loop, and the quality of the suply depend from the generator sine quality. I hope this question is not too "strange"
Next, I got a douzen of BUX98C, TO3, 1200v30a, comming from used Step motor suply. These are NPN, and I'd like to build a power amp with 4 of them, in a quasi-comp output configuration. I don't know if they are suitable for linear amp. Else, is it possible to build a H-Bridged class D swithing amp, with BJTs, with a PWM less than 20khz. This amp is suposed to be for a subwoffer, filtered at 100 Hz or less, the HF responce doesn't matter, and the sound quality is not a factor...

Hope is clear
Thanks

[Jan Dupont]

The answer to your first question is right here in this thread:
high volt amp (dumb theory)

Re. your second question regarding a NPN-amp, there are many schematics in this forum. Here is one: SUMO Power Amp