Okay, we're getting a lot closer now but B+ is lower than I'd like, at ~330V even with a GZ34 which doesn't drop that much. Target is 350V.
The current supply is LCLC, with a 390v.d.c transformer > GZ34 > Chicago 8hy choke > (85ohm) > 100uf > 5hy Lundahl (15ohm?) > 100uf
I know y'all are big fans of that second choke, but pulling it would get me closer to my target voltage... though I'm not sure just how much closer. Alternatively, I could "tune" the voltage up with a small value cap just before the choke -- I've seen that referred to as cLCLC -- but I don't know which is the more "elegant" approach.
Anyone care to weigh in?
Yup, I've done the cLCLC trick to tweak... it's a great way to make "nearly correct" flea market transformers do what you want! The question is, I think, which will bother your idealism more? That your PS is not 100% truly choke loaded, or that your B+ is 5.7% lower than predicted? What about increasing the 2a3 resistors a smidge so the B+ is bogged down less? Lots of ways to achieve inner peace.
Will you be able to hear the difference? The only way to know for sure is to make these changes adjustable while the amp is running. For instance, add a 100 ohm pot on a 20' piece of cable in series with the cathode resistors. Or, a DPDT toggle switch to the ground side of your leading capacitor. It's not without risk, but your bloodline is well established, right?