I've just come through the first couple of gigs with my Mesa 400+ post 12AU7 mod... and I've gotta say that the improvement in headroom and EQ flexibility is very nice. I can see that this wouldn't necessarily be a mod for everyone, but I think I'm one of the ones who it was meant for. However, what I can't say is that I've settled on any particular new setting yet. Right now, I've come through these first gigs with the Master dimed (something I couldn't do before the mod)... with Input 1 anywhere from 3 to 6, depending on the venue. As far as the EQ, treble is set at 2, bass at 3 (pull shift) and mids at 10 (the graphic is only switched in when I use my Rickenbacker...). I wonder if the 10-2-2 (Mid-Bass-Treb) "flat" settings still apply post mod? I'm still debating whether I've arrived at a sound that I can really dig (the rest of the band says it sounds solid!). I am getting really good punch and clarity with those settings, so I know I'm close. How about you? After the 12AU7 mod, where have the settings on your 400+ ended up at? Also, are any of you doubting whether the 10-2-2 (M-B-T) setting still equals "flat" with this mod?