Black Face Deluxe Reverb Problem-Voltages

[tele_player]

That should be pretty simple, Google 'ab763 reverb both channels'.

[theundeadelvis]

So, I've moved my PI ground from the preamp point to the power amp ground point, and I moved the preamp filter cap grounds to the preamp ground point. I did this because I had a bad hum. It's better, but I still have hum. The weird part is the hum is the worst when the vibrato channel's volume is at zero. Any words of wisdom? Thanks guys!

[jjman]

It looks like there is/was an issue with the heater center tap. The filament pins' ac voltages (to ground) should be the same, but your voltage list showed them differing.

What do they show on the power tubes?

[theundeadelvis]

I re-checked the heat voltages and they seem pretty much ok (not sure what I did the first time I checked) Pretty much every tube 3.3 on one and 3.1 on the other.

[theundeadelvis]

I also noticed the hum goes away if I remove V4 or V6(PI). I switched out those tubes and that doesn't help.