I have a Carvin X-60 combo amp and one of the two EL-34 power tubes fell out of it's socket and broke today. I have a gig tomorrow and need to fix this fast. I have a few questions… -Will I hurt my amp if I replace the tubes without re-biasing my amp? (don't have the time or cash to do that) -I live in NYC and a quick call around found me a pair of JJ's at Main Drag, a pair of Electro Harmonics tubes at First Flight and a pair of Groove Tubes at GC. Which would you go for? If you have a strong recommendation for something other than above and know a place I should call let me know. Thanks so much!