GZ34 after a pair of diodes and RC filter (Genz Benz Black Pearl guitar amp)?

[merlin]

Thanks, that's great to know - those Mullards are pricey!

I quite like the idea of doing it the Black Pearl way but using a junk-box tube (some worthless old TV pentode or whatever), wired as a diode. I've not actually tried it though.

 

[capacitorless]

This is the chassis. It fits nicely with room to spare on the Mesa halfback 2x12 it's going to reside upon. I have a slightly oversized cabinet for now. I'll make one to my specs (or more likely have one made) that simulates the cosmetics of a SLO.

Note the spare area surrounding the stock transformers. There's no PCB under them, so swapping different iron is easy mechanically (plus the boards are on standoffs). In the past I wouldn't consider anything not turret or point-to-point for a mod platform, but this should be good to go.

 

[capacitorless]

Thinking this through further, I'm going to back up, follow the advice of @merlin and keep the power supply voltages the way they are. I was planning a SLO preamp (only) in another chassis, and I can run the output of that into the power amp section of this amp and compare things/adjust and so forth.

(edit: part of the reason why is that the other 3 tube types that are part of the 6973 "family" are happy with significantly less plate voltages. I'm not stuck on the 6973 specifically and this will give options. Plus I don't care about maxing out the power output - this is an effects box, after all )

It's not gonna be a SLO clone for multiple reasons, so it doesn't have to be perfect. Just ballpark and I'm a happy camper.