First Tube Amp: Advice? Keep spare tubes on hand?

I always keep a working set as a back-up, and all new sets I buy, i burn them in for at lest 20 hrs. to be sure they are good. Jallen

You have been given great advice mine is don't be afraid of the multimeter(DVM);very easy to use and a very needed tool for manual bias;also checking blown fuses that look good but don't ohm out as a short and read open.

Again, your replies are concise, well reasoned and very much appreciated.
I posted under a new thread about a problem(?) I'm having.
The bias on my new amp is specified at 1.5 volts. The left side will not bias above 0.5.
What should I do and/or not do?
Help me, oh help me please.

First off did that tube arc? Are their any burned resistors around the output tubes? Was it always drawing this low bias voltage, or did this just happen? If no resistors are burned possibly swapping the outputs might help to diagnose the problem. If the problem moves then you know its the tube and the tube will need to be replaced as it has been damaged. If the problem stays at that tube socket then there is a problem with the voltages being applied to that tube socket or the circuit that supplies that socket. That being said, before trying any of these procedures, I would strongly suggest you contact the manufacturer of this amp as they can help you trouble shoot your problem. I don't have your amplifiers' circuit diagram in front of me. Hope that helps....G

I don't know how your amp is setup to bias; it maybe a tube at a time or pairs or quads; I would talk to the manufacturer and tell them what you are measuring;then go from there.
If this were my amp I would move tubes from left to right channels to see if the measurements move or change;also inspect the pins on the tubes for oxidation;could be some buildup that needs cleaning as well as the tube sockets themselves.