I noticed in other noisier places that you seem to be getting ready
to put a Seth together. I also noticed that you had done a 6B4G
version a couple of years ago. Since I'm collecting bits for one,
prompted by a Magnequest clearance of S240s a couple of weeks ago, I
thought I'd check in with you. I currently expect to build the signal
circuitry to the Mark II spec, but possibly do a different power
supply. I have several 500 VA step up/down power transformers that
would give 234 and 468 secondaries (AC), and thought I could use two
bridges to make the 320 vdc B+ for the 2A3s and around 420 for the
driver stage. It this excess complication without commensurate
benefit?

For those unfamiliar with this amp check this link:

http://www.magnequest.com/diy_lessard_2a3pp.htm

I have a DAC to assemble before I start on this, just collecting
pieces now.

Thanks,

Skip

Thanks for the reply. Too many sites these days, it's easy to miss
something, somewhere. In any case, I was wanting to isolate the driver
stage from the output stage, and since I have 2 220 VAC secondaries on
the power transformers, I was originally thinking to put one bridge
across one of the secondaries, and then another across both in series.
I have since seen a discussion on AA that suggests that this would be
catastrophic (though I don't quite see how). If I had the 400+ B+ for
the driver, I would drop it with a large, hot resistor and maybe a
choke to further isolate that stage. I suspect that simply using one
secondary with a CLCLC for the output at full voltage and a choke
loaded LCLC(maybe one more LC) for the driver would work as well or
better and avoid the higher voltage complications.

Skip