I've been talking with Bob at eurotubes.com and have some tubes ordered for 2 amps......the ol' gibson GA-5, and the tripple XXX. I'm switching the XXX's 6L6's out for some EL34's and some lower gain rated pre-amp tubes. any idea's on what I can expect a rebiasing to cost? As for the GA-5 I'm getting a cooler grade 6V6 and an ECC83S pre-amp tube to give it a little more sparkle. Luckily this amp is cathode biased so no rebiasing will be needed. Bob has been very nice and informative and I would defanately suggest dealing with him if anyone is in the market for new tubes. I'll try to record a few before and after clips so we can all see, or rather hear, the difference.