New tubes and bias but loud hum

[Enzo]

You can make it a discussion of physics, but it only will be a discussion of hum when the entire context of the circuit is entered into it, not just an electron moving from cathode to somewhere else. Where do those currents flow?

[fixitrightthefirsttime]

Agreed.

[Amp Kat]

KB, thanks, you are right. I mis-spoke. The 5150 lifts the POWER TUBE heater 6VAC to +24V. R69 pulls it up.

Well you got me on that one as I didn't think the power tubes were elevated but as you mentioned they indeed are.