So I'm in the middle of rehearsal last night when all of the sudden my amp goes quiet - volume completely gone. I look in the back and all three preamp 12ax7's were toast - not glowing hot at all. The power amps tubes were still glowing but obviously that did not matter. Thankfully, I was close to the store where I purchased it and even though they were closing up for the night they let me drop it off. What happened? The really frustrating thing is I had just re-tubed it this past Saturday and it has been working fine. I am curious to know if this has happened to any of you and if it is a minor repair due to a short or something more serious. Thanks!