Thanks for the help pstrings. Eventhough the amp has a bias switch to switch between the tubes, will it still need to be checked or will it be as simple as plugging the new tubes in and flipping the switch? Also where would the best place be to get new tubes? Would it be safe to buy them over the internet or better to buy them from a dealer? I actually live in Mississippi about 150(give or take)miles from meridian where the peavey plant is(just a little FYI).