A friend of mine has an Axe FX 2, a Matrix GT1000FX (2U), and a Mesa 4x12. He's had multiple problems with the amp sparking, cutting out, and finally it just exploded and died. Multiple times, he had me over to try and troubleshoot, since I guessed it was an impedance issue, and the cryptic ratings listed sounds like each output can have variable resistance, but there's no markings, or no way to set the resistance. He is used the AxeFX as his preamp and obviously using the power amp and cab instead of the simulations on the Axe. Anybody have any freaking clue as to what to do? He's sent it in for repair/a new one, but just so this doesn't happen to him again, and because I'm definitely not the authority on this situation. We have hooked it up in all configurations (Mono and stereo, with either of the single outputs or the bridged output). Ratings on the cab is 2 ports with 4 ohms for split/stereo, and 1 port with 8 ohms mono.