Tube Biasing? What is it?

[Spencerthegreat]

Hey guys. I've heard talk of "biasing" a tube when replacing and old one for a new one. What does this mean exactly and how is it done? Do I have to do something special when I replace tubes? I've done it once but I didn't do anything.. I just swapped out the old tube with a new one. Could this seriously harm my head? It sounds more or less the same.

[countrybass007]

I always get matched sets for my amp directly from Mesa. Back in the 50s when a tube went out we went to Walgreens and bought a new Sylvania to replace the bad one. It worked fine both ways.

[SactoBass]

Originally Posted by Spencerthegreat

Hey guys. I've heard talk of "biasing" a tube when replacing and old one for a new one. What does this mean exactly and how is it done? Do I have to do something special when I replace tubes? I've done it once but I didn't do anything.. I just swapped out the old tube with a new one. Could this seriously harm my head? It sounds more or less the same.

Here is some info:

What is "tube bias" and why do we have to re-bias new tubes? - Yahoo! Answers

[JimmyM]

Biasing only needs to be done if your amp has power tubes. Looking at your profile, it looks like your amp only has a preamp tube, so you don't need to worry about it.