What is the best sounding GZ34 / 5AR4 rectifier tube you've ever heard?

Bliss:

There are some major spec differences between 5ar4 and 5r4gy(s).

Aside from a considerably higher voltage drop the 5r4 also has a faster warm up time.

Not familiar with 5u4g, but once looked into the other and decided not to go there with my amps.

DeKay

@dekay Good point. While most units that utilize GZ34 and 5AR4 can also accept other variants like 5R4, 5U4G and 274B, not all do. You have to make sure they can handle the differences. That said, I’ve owned about a dozen units from different manufacturers that used these variants, and only one of them, a custom 45 Korneff clone made by Oliver Sayes, would not accept a 5R4. That was an incredible amplifier nonetheless. 

Bliss:

This was for my Pilot 232, which in stock configuration already runs the outputs rather hard..

There were suggested mods @ the time (like adding a t/f choke to the PS), but I didn't want to bother as I had moved on to 300B and 2A3 amps.

I still have it, but @ this point it would have to be properly refurbished (especially the PS considering the higher AC wall voltages experienced now).

I reformed the original multi section cap twice, but can't imagine that that the 3rd time would be a charm.

Had to replace the large ceramic resistor off the rectifier on both of my Pilot amps (232/240) which is telling.

DeKay