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

Tvad and Mapman are right: have at least one of each type of tube your amp uses available to swap out (in sequence) the amp's tubes in the case of failure. by far most problems you're likely to encounter will be tube failures. you're almost guaranteed to need to replace the odd tube now and then, so you may as well have the spares so you can avoid unnecessary 'down time'.

Make sure you dont buy off ebay.Go to Brent Jessie,Upscale,and 3-4 others here I cant remember.Do a search...

Hate to be the fly in the ointment but there are some amps that require a resistor replacement before attempting to swap out the bad output tube. This depends on how the tube failed. Some manufacturers use these resistors like fuses. If the resistor fails, like a plate, grid, or cathode resistor, it can minimize damage to other parts of the amplifier. If a new tube is installed and the resistor is not replaced, it can cause damage to your brand new tube. I would probably contact the manufacturer to make sure you can easily swap out output tubes. Small signal tubes like the 12AX7 or 6922 can be easily swapped out as long as the amp has been turned off first. G

I tend to agree with most here, especially Sogood51's reply. I would caution against buying spare tubes too soon. Make sure you like the amp first. I've made that mistake before, buying NOS tubes before the amp/preamp got here, then finding out that I didn't care for the unit no matter what tubes I put in.

Relax, once you find out if you like the new tube amp, there will be plenty of time to get into 'tube rolling'. Which usually leaves plenty of spares laying around......sometimes many more than you'd like to have lying around.

Cheers,
John