What the heck is bias anyway?


I'm getting a new tube amp that will need to be biased. The process of doing it seems fairly straight forward, but I am curious: what are you actually doing when you bias an amp? In english, for us technical Ludites.
grimace
I think of the bias current in a tube amp as being similar to the fuel required to keep an engine idling. The engine must be running (idling) prior to applying throttle to accelerate (voltage). Maybe over simplified but works for my mechanical engineering brain.

I have a Cary SLI-80 that I must use a meter to set the bias current and it is very easy to do. I wouldn't freet it and it doesn't sound as if you are. Enjoy your new amp it is a beautiful piece to behold.

Chuck
Well, whatever the hell it is, it sounds really nice!

Thanks for the answers and food fight! :-)
I had a Cary V12R before the CAD 120's. You need to use a meter, not just depend on the red led's. They run hot, but are a great amp. The led's show that the tubes are good. Happy listening.