JMP50 with GZ34

[roberto]

If you are using the JTM50 specs with a GZ34 as rectifier, it's absolutely normal that the sound will be mushy. Your amp is no more working on the foreseen working points, but something between 50 and 100 Vdc below (plus the bias will be cold) when playing loud.

[Littlewyan]

I upped the mains and screens to 50uf and it sounds so much better. I think it was ghosting pretty bad before when everything was turned up to 10 but now its fine. I think I'll probably end up soldering diodes across the GZ34 socket and having the mains at 100uf with the screens at 32uF.

[RockinRocket]

What OP transformer are you using?

[Littlewyan]

The Classictone 40-18025, 3.6K 50W.