Poll: To bias or not to bias?
Poll Options
View poll results: To bias or not to bias?
15 79%
4 21%
Voters: 19.
Hey guys, this is really getting to me! I've been told that I will need to re-bias my amplifier (JCM 2000 Tsl602) when I have renewed the power valves, even though I am replacing them with the EXACT same type and make of valve!

Any help considered very welcome,

Ben Wojciechowski
uhh... wut does that mean??
<Raven> I got so baked last night
<Raven> that I WOKE UP high o_o
<Raven> Do you have any idea how euphoric that is?
<Raven> I felt like I was being born.
even valves of the same type, from the same company, can vary in spec and quality. When a reseller matches tubes for you, they test a bunch, and find sets of tubes that are close to eachtother in grading and specs. Unless you can match a grade number/color code, or have extra tubes from your previous matched set, you should get the amp biased for the particular set of matched tubes you buy. You can probably get away without doing it, but if you want the best tone, and longest tube life, you should have it biased IMO. This also depends if the amp has an adjustable bias, and how it's designed (ie cathode biased).
"The fool doth think he is wise, but the wiseman knows himself to be a fool." - W.S.
amp clips
amp vids
if you get the exact same tubes and match the set up to the old set with the same specs you dont need too, but you have to match them exactly, other than that you should take your amp to the shop and have them show you how to re bias your amp.
make Industrial and/or experimental electronic music? Join my group!