Maybe it's just me, but I always make certain I have any parts and tools I need to do on-site repairs for whatever gear I happen to be using at a particular gig, including tubes.
Question for Ken: I wonder if the problem tube(s) effected the tone as demonstrated in your videos.
Pretty sure not... seemed to sound great and then just didn't work when I turned it back on a bit later. I'll know tomorrow. If the new one sounds at all different, I'll fess up and re-record. However, I hope it doesn't!

