OK, it didn't really blow up, but it did blow. Was swapping guitars with the power on but the standby off and heard a pop, followed by the sound of a turntable needle sliding off of a vinyl album (for those who don't know that sound, it isn't good). I bought the amp on line (new) so called G-B for help. [Jeff Genzler had been very helpful via email in my decision to get one.] The tech said it sounds like a bad tube blew and the heat led to a short on the circuit board. I brought it to a service center here in NJ and should get the amp back in 10 days. The retailer is not like MF or M123 or ZZ who has a no questions asked return policy. One thing concerns me a little: the guy at the repair place said it had had some problems w/ G-B and was surprised that they were still a warranty service center. Would this bother you? Also wondering if this is just a freak thing or something I should be concerned about long term. The tech at G-B said he's heard of something like this happening once before. Thoughts? PS - I was really enjoying the amp for the four days it worked.