I'm planning on buying a Marshall jcm 800 on craigslist or eBay, and I'm just wondering what I need to know about the tubes inside n how to know tht they work or if they're any good and the other things in the head and if to buy the amp or not
things to check when you get it: turn it on with cab connected if its a head, see if all tubes are glowing orange/blue. if one or more isnt then it is bad and needs to be replace. i beleive there are 2 el34s in the power and 4 12ax7s in the pre amp. to change them unclip (if it has any clips) and pull up firmly you may need to slightly wiggle back and forth to get loose. good luck man i hear those are good amps never tryed one myself though.