Re: How would you setup a Mesa MK IV....?
Decide if you want a gain boost for solos or a volume boost. Any stomp box before the amp will be a gain/sustain boost, but not really give you much of a volume boost if you're already overdriving the preamp hard. If you want the same overdrive amount only louder and more up front, then you need the EQ, either the one on the amp or a pedal in the loop. Once you figure that out, it will narrow down the suggestions a bit. I for one would have both the SD-1 in front of the amp, and the EQ pedal in the loop. That's probably because I like the MK IV with the amp's EQ on most of the time. The tone knobs do too much pre-gain altering to be used to really shape the sound.