#1
out of the power, rectifier, pre-amp, phase inverter, effects loop, and reverb tubes in my amp, i know the power tubes have to be biased when replaced and the pre-amp tubes do not. but what about the rectifier, phase inverter, effects loop, and reverb tubes? which ones of those have to be biased when replaced?
#2
recitifier does not need to be biased, completely different function. The PI, fx loop, reverb, etc.. are all still preamp tubes, and do not need to be biased.
"The fool doth think he is wise, but the wiseman knows himself to be a fool." - W.S.
amp clips
amp vids
#4
to bias an adjustable fixed bias amp correctly for the tubes, you need to find the plate voltage of your specific amp by measuring it, and then use the plate dissipation of your tubes to find the correct bias current. Unless you have the tools like a bias probe and DMM, I would let a tech handle it. It's working with very high live voltage, so unless you know what you are doing, it's better left to a tech.

Depends on your amp though. If it's cathode bias, you don't need to worry about biasing it yourself. If it's non adjustable fixed bias, then you can't bias it without some modifications like adding a bias pot.
"The fool doth think he is wise, but the wiseman knows himself to be a fool." - W.S.
amp clips
amp vids
#6
what amp is it? Maybe we can find the specs on their website. They will usually have something listed there or in the manual.
"The fool doth think he is wise, but the wiseman knows himself to be a fool." - W.S.
amp clips
amp vids
#8
as far as I know, that's an adjustable fixed bias amp. I would email B-52, and ask them specifically about using new powertubes, and what you need to do. If it's a non-adjustable fixed bias, you should buy tubes from a dealer that will know and test the tubes to work with the B-52's fixed bias. Whichever route you go, you should make sure you buy a matched set of power tubes so they are all running under similar parameters.
"The fool doth think he is wise, but the wiseman knows himself to be a fool." - W.S.
amp clips
amp vids
#10
on nice, actually, Bob would know too. That guy has forgotten more than I'll ever know, and he's usually very helpful unless he's pissed off, lol. Also check out Dougstubes too, he carries more than just JJ if you want some options. I like the JJ tubes personally, but it's nice to look at options. GL
"The fool doth think he is wise, but the wiseman knows himself to be a fool." - W.S.
amp clips
amp vids
#11
i orginally went through dougstubes.com and asked him about the tubes. he gave me a list of what he thought would work then i went to euro tubes and checked them out too. i personally like the euro tubes set more. and even though this is my first tube up grade, i kinda orginally wanted JJ's becuase everyone has said how good they are. plus its cheaper. lol and ill shoot bob an email and see if he can help me out. thanks again man.
#12
no problem man. and yeah, I checked out that high gain kit with the gold pin V1. Sounds interesting, V1 is an important tube being the input. I've had quite a few orders from him, and I've had good luck with all of them so far. Wow though, didn't realize how many tubes that thing uses, that's some loot for a tube change!
"The fool doth think he is wise, but the wiseman knows himself to be a fool." - W.S.
amp clips
amp vids
#13
well i sent both bob and B-52 a message about the power tubes, so im almost garenteed a right answer. and i actually wont be getting the gold pin kit. it says at the bottom of the discription "not recomended for the combo version" which i have. but hey, im replacing the old crappy stock russian tubes, so anything will sound better. and yeah it takes 12 tubes. 4 power, 4 pre-amp, rectifier, phase inverter, reverb, and effects loop. but hey, if it means ill get way better tone then the tone i have now, its worth every penny!