only got to play her for an hour, than heard a little bit of hum, followed by the amp turning off. mains fuse was shot, and one of the power tubes was dark..i traded amps with a guy who had used this amp for gigs and practices for a year with the same tubes (all mesa besides the EL34's) so im wondering if the tubes were damaged during shipping and just went bad. my buddy and i put STR 447's out of his mark V, put a new 3A slo-blow in, and she turned on, worked for a minute or two, then all of the sudden we lost volume like crazy, down to practically no volume at all..i took it to a tech, and my "seller" agreed to pay for the tubes, but hopefully theres no major damage..totally ruined my new amp day.