New schematic for review

[redelephant]

Don't think 9mH will do much for ya. That only handles some HF. I assumed the choke was 5-10H, that's 1000x more than your 9mH part.

[Howlin' Mad Mac]

Well adding the SS diodes is really just a little extra insurance in case the high quality 5Y3's available on today's market should die unexpectedly the supply should still be rectified, just at a slightly higher voltage which the amp should be able to handle until the 5Y3 is replaced. As far as the choke output voltage from a Champ transformer should have enough to spare, in fact I think the Champ did have an input choke prior to the 5F1 revision... also thought about going all octal & using a 6SN7 instead of the 12AX7 only I don't have one on hand. As for estimated voltage at B+ I'm not real good at figuring those things out but guessing about 350 - 365v.

[MWJB]

6SN7 has much less gain than a 12AX7, is more prone to hum and is only interchangeable with 6SL7 (still less gain than a 12AX7). Stick with 12AX7 then you can try 12AT7, 5751, 12AY7, 12AU7, 12DW7 if desired.

[Howlin' Mad Mac]

Hmmm... Yea I see what you mean. I've sourced out a few possible replacements, here are my choices: 4h/40m, 4h/50mA, or 9h/40mA. Leaning toward the 4h/50ma although I'm curious to know which ya'll would pick... or would you suggest something else?

[Howlin' Mad Mac]

Yea I'm aware of 6SN7 having lower gain & not going that route anyway... only considered it because it would be all octal tubes. Personally I prefer 12AT7's or 5751's to 12AX7's myself but they're so expensive these days & very hard to find ones that aren't microphonic.

[MWJB]

They're cheaper than new 6SN7s, even cheaper than the Russian 6H8C. I have a couple of 6SN7 powered amps, it's cheaper to buy 6L6 power tubes!

[Howlin' Mad Mac]

Ok so let me get this all straight... do away with NFB altogether? That's what I was thinking too & had it originally drawn up that way but then got some falk for omitting it so I added it back in. As for the 1K in series with the plate, yes it's a typo, should be in series with the screen correct?

[Howlin' Mad Mac]

Value changes were also "borrowed" from a Vox SE design as a "client" desires a more British classic chime-like tone. Any suggestions?