rectifier swap

[angelodp]

are there any adverse issues with swapping what is called for in my amp

a 5AR4 - for a GT5U4 tube

Amp is Super 6G4 fender

[sidehatch]

usually fender amps can tolerate the change. The amp must be rebiased when switching rectifiers.

Also, if the amp has old electrolytic caps it can be a bit dangerous swapping rectifiers.

If your amp has a 5u4g and you want to go with a 5ar4 it will raise b+ voltage and give you less sag so you gotta be surer your caps are strong..

Personally, I swap all the time. I go from a 5r4(most sag) to a 5ar4(least sag) and rebias.

Also, be advised that the 5ar4 and the 5u4 have different filament amps but if your caps are strong its safe.

Id first decide how much sag you want and go from there.

Here's a helpful chart that helped me leard what will work:
http://kcanostubes.com/content/newslett ... rticleID=3

[Firestorm]

Also, be advised that the 5ar4 and the 5u4 have different filament amps but if your caps are strong its safe.

Good advice up until right here. Caps got nothing to do with it. It's just about can the 5V PT winding supply 3 amps or only 2 amps. No caps involved. But most Fender PTs are up to the job.

Of course, IMO, the 5U4 is the ugliest sounding rectifier ever made. Why use it at all?