I sold a bogner shiva to get the mark v, and I played the herbert yesterday, so much more brutal and tight than a bogner, destroys and rectifier. I have played alot of amps in my day, I have access to some of the best amps in the world living in Los Angeles , the mark v I have is still a good amp but you are right, what annoys me about it is the lack of effect the mid treble and bass knobs have, it's not like the herbert where the sweep is really pronounced and I can HEAR a difference when the knob is changed, not sure what's up with my mark v, maybe that's just the way they are. Don't get me wrong it gets a fantastic sound and I could live with it, just want to see if anyone can recommend a way to push it into diezel land....