We've talked a lot about the contour curves and the EQ here, but we've not really touched on subtractive EQing.
I was practicing last night with my MG800 and headphones, and I was using my Pawn Shop Mustang bass. The humbucker has a funky midrange and with most amps/cabs that add bass and low mids, it's not noticeable. But with the MG800's clarity, the funky mids on the pickups really jump out. So I did a bit of subtractive EQing - dialed in the odd frequency and pulled down the mids - and it cleaned it right up. After that, I got thinking and turned down the bass a bit and I got this really cool, gnarly tone from the Mustang. I haven't clipped my nails as I usually do so I was getting a bit of bite with my fingers and having a blast jamming out.
My default setting is always to use the EQ to enhance the sound by boosting certain frequencies, but there's just as much power (maybe more) in pulling down the unwanted frequencies. Because the mid sweep on the MG800 has such a huge range, I was able to dial out the odd mid frequency and still have some balls with the tone.
Jeff - this thing is filled with surprises that just keep coming. I can't speak highly enough about the amp, although I daresay I'm trying!