So, since I sold my AT-100 I had a high gain preamp tube set (as well as the effects loop and balanced phase inverted of course) and 4 6L6 power tubes. Last night I decided to try the JJ preamp tubes in my Mesa Triple Rec and to my surprise I didn't like the sound at all! It was way too bright and trebly. It took away the top end Mesa "fizz" but just made the sound too darn bright. Let let me say these tubes on the B-52 kicked ass! They were far better for the AT-100 as they really improved the sound. They didn't have the same brightness affect with the AT-100 as they did with the Mesa. But, fact is I did order the tubes specifically for the B-52 head. Anyhow, the power tubes are brand new tubes! I put them in one time and decided within 15 minutes I prefered the Sovtek's sound so I took them out. The preamp tubes have only been used for 3 weeks of very light in home play. The tubes included are: 4 6L6 power tubes 4 12AX7 hi-gain preamp tubes 1 12AX7 standard (for the effects loop) 1 12AX7 balanced (for the phase inverter) 1 12AT7 for the reverb 1 GZ34 rectifier tube The total price this cost me is $139. I'll sell this tube set for $70 (which is half price!) plus shipping (which is cheap - tubes are small and light). I'll only accept PayPal and money orders. Those that are interested please e-mail me at: firstname.lastname@example.org Rev.