Question about power tubes for Rectifiers

[Decon_Frost]

Hello everyone,
I have a Dual (rackmount) Rectifier with the 5U4G power tubes and just recently had one of them blow on me. I also have an extra 5U4GB tube from back from when I owned a Triple Rectifier. Does anyone know what would happen if I put a 5U4G tube in with a 5U4GB tube?

 

[domct203]

Welcome to The Board.

The 5U4G & 5U4GB tubes are rectifier tubes which convert AC voltage to DC voltage. The Power (or Output) tubes are the 6L6GC (or EL34).

You can safely run 5U4G & 5U4GB tubes together. The result of this depends on how you run your amp. If you only use Diode mode rectification you will not notice any difference. If you use Tube Rectifier mode you may notice a little more power supply sag at high volume levels due to the nature of the 5U4G.

BTW- Mesa has not used 5U4G tubes for a long time. I suspect those tubes are very old, and you should change out the other one before it blows as well.

Dom