Hi all!
Does any of the forum members have experience replacing the rectifier on a 5U4G?

Voltages will be a bit lower.
I'd recommend to stay with the GZ34. Add rectifier diodes in series (1n4007 or better), and never use the standby switch. Leave it on or remove it completely.

Not a good idea to use a 5U4G in an AC30.
Heater current of 5U4G is 3A, GZ34 is 1.9A.
So the 5V heater winding will overheat.

Thanks, I know that the filament current 5U4 is 3 A.
But I don't know what current the 5V winding is designed for...
The transformer for AC30 from Inmаdout, for example, is rated at 3A...

But I don't know what current the 5V winding is designed for...

I don't know either, but it seems unlikely that the original Vox PT could safely handle a 60% increased current.

Another benefit of the GZ34 is its delayed heat-up, resulting in delayed ramp-up of B+.
This saves tube life.

Why don't you want to use the GZ34?

My 5AR4 is dead and there is no replacement. But my friend offered help in the form of 5U4)))
I have already ordered a new 5AR4, so the issue can be considered resolved.
I thank everyone who cares! :bier:

I guess you know that 5AR4 is just the american name for a GZ34?

Yes, sure. Thank you :topjob: