Never too old to be reminded to listen to others. My guitarist has recently acquired a full Marshall Hendrix doublestack - one of 600 blah blah... While we are not a metal band (think blues/rock a la Stevie) the whole dynamics thing has made me consider another Bergie to go with my NV610. We are old troopers and understand onstage volume etc but still like a bit of power behind us. Anyway, I read recently that Jim Bergantino advised another TB'er to get a bigger amp before adding another cab to his 610, so decided this gig to really push the Mesa and also took out PsychoBassGuy's 12AU7 tube mod and replaced it with the original 12AX7. It was a big club, 600+ capacity and a good PA provided, we just took our back line. Long story short, the NV610 just soaked up the power and I had no trouble getting a good onstage mix and hearing myself, even with some lead guitar coming through the monitors also. This speaker just never ceases to amaze me - and also the other musos in the audience who had never even heard of Bergantino. The tube swap?? - well at the end of the second bracket I put PBG's 12AU7 tube mod back in. The Mesa with the original 12AX7 just did not have those wonderful creamy mids to which I have grown so accustomed in the last 18 months. I worked the gain and master a bit more than usual to compensate for the 12AU7, and the Bergie just lapped it up. Conclusions? The Bergantino NV610 remains my main gigging speaker and it is difficult to imagine doubling it unless on a big outdoor stage(in which case I would probably have bass in the monitors and side fill anyway). I had forgotten what a wonderful difference PBG's 12AU7 mod makes to the Mesa 400+, after using it for so long it was interesting to go back briefly. The amp does appear louder with the original 12AX7, but I doubt that the volume is useable up to ten without running out of headroom, whereas with the 12AU7 I can crank it pretty well all the way.