Tube failure -- what would happen in worst case?

I did not bother to bias my tube amp

Why not?Just curious.

I guess I was lazy and ignorant. I assumed that a new tube amp was factory biased and I should not fiddle with it, and also I did not want to damage my amp by screwing up. Now I feel like I need to know more about biasing.

I guess, this shows what would happen?
http://www.youtube.com/watch?v=_KOjn9ii2Jg&feature=related

If you have to, pay someone to show you how to bias your amp. Small differences in AC voltage can change the bias. Just because the amp is new doesn't mean your house voltage is the same as the factory where the amp was built.

Another good reason to have someone show you how to bias your amp and use the proper tools is so you don't electrocute yourself.

Auto bias circuits can also fail.