Hello. Yesterday I was noticing that some of the pre-amp tubes had stopped glowing and lately my amp has been lacking some gain. Is it the pre-amp tubes that is the problem?
Buy some new preamp valves. JJ's are good and reasonably priced. Keep your old valves as spares.

If the new valves still won't light, then there's a problem with the amp.
Roses are red
Violets are blue
Omae wa mou

Quote by Axelfox
Mentioned in your other thread to check this thing out throughly before trading. Sorry to hear about your problem man but Jet Cities are cheaper amps and can sometimes have issues. If it's not the tubes could be a fuse.