Bias Blues

[sepulchre]

The Classictone 40-18015 has no CT. So, although I see and understand using voltage control inline with the main HT, could a Zener be used between the "back" of the rectifier bridge and the ground?

[martin manning]

The Classictone 40-18015 has no CT. So, although I see and understand using voltage control inline with the main HT, could a Zener be used between the "back" of the rectifier bridge and the ground?

You could, but a MOSFET is a better solution, about which there is a lot of discussion here: https://ampgarage.com/forum/viewtopic.php?f=6&t=27035
I'm not a fan of that kind of thing, however it's done. For your current situation, I wouldn't get overly excited about 430V on the plates as long as you are running into a reasonable primary impedance and you set the idle current responsibly. That's where the Fender Tweed Bassman's 5881's operate.

[sepulchre]

Thank you Soo much, Martin! I got it biased a little on the cool side and after a bit of tweaking on the 1st two stages it sound Great!

And thanks to everyone. Once again with all the help from you guys what looked like a disaster turned into a success!

Plus, I have some really interesting stuff to read and think about.