A few days ago I posted that my single rec was actin weird, a real lack of gain, regardless of settings. Well today I installed the new preamp tube set from DougsTubes and OMG what a difference!!!!! I bought the amp used and I now know that there was something wrong from the beginning. Sounds awesome now, plenty of gain, I'm so happy!! I was almost considering selling it, now that I hear her all tuned up I can say that I will never part with her. I just wanted to say thanks for guys input and direction, as this is my first tube amp. The gain and sustain is 10 times better, Im not sure what tube or tubes were bad or weak, they were all mesa 12ax7's, and I dont care, she sounds amazing!!!!! Thanks to Doug also for the fast shipping of the tubes!!!!! I'm goin back downstairs and jammin !!!!!!!!!