Well, not to buy into the hype, but wanting to check these things out, GC had one 12ax7m left, and quoted me $16 for it. At that price I had to see. Well. I play a Zinky Superfly. I put it first into V1 (SF has 4 preamp gain stages, and one 12at7 as reverb/effects loop buffer/driver). Some disappointment here. VERY dark sounding. Muffled even. Added alot of gain to my clean sounds as well. Not good gain, very 'fuzzy' and unfocused. Messy. Off to V2. New issue Tung-Sol in V1, JJ's in the others. Now it's just plain nasal. Midrangy. And still that irritating fuzz. V3 and V4. Now it's just messy. Can't control the distortions and gain stages of the SF. Final analysis: Not a good tube for this amp at least. I'm sure a bright amp would be a better match for it. I'm in no mood to pump up my global treble to cut through the fuzz....shouldn't have to do that. I went back to Tung-sol in V1, JJ's in others, and suddenly it was 2 hours later and a smile on my face. I guess that sais it all. At this price, I expected more. Good thing I kept the reciept. Your results may vary.