all eq knobs are pre distortion and shape the distortion as well as the eq, with the treble being the strongest, then bass, then mids. This is totally atypical from your average amp. Rectos, for example, are the opposite.
However, some are starting to catch on to the whole "cut bass early in the circuit to make it tighter" in amp design, making boosts less and less necessary. Peavey XXX, Engl PB, and JVM are some examples. Tonally, the MKIV is so unique, though, IMO. The highs are less gritty than the aforementioned amps, and so it's smoother. Just a really fine fine amp. My mkivA is never getting sold, unless it's another MKIVB, and I would have to try both side by side to be convinced.
