[bi7340aa]

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

[roseblood11]

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.

[Helmholtz]

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.

[bi7340aa]

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...

[Helmholtz]

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?

[bi7340aa]

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!

[Helmholtz]

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

[bi7340aa]

Yes, sure. Thank you