I agree that a 3-rated set of Groove Tubes is likely to distort early and often. The set of GT7027's in my Ampeg are rated '4', and I find them a bit dirty, (but in the nicest kind of way :) ). I'd like to get my hands on a set rated at 7 or 8 and see how many rows of the audience I can melt before I get a nice, tangy, crunch! :D