Ah, the amp of kings.
There's a sweet spot on the input where it goes fat before it drives. FInd that.
FWIW, there's a lot of conjecture as to what the bass, mid and treble on the heads actually do. There's a lot of in-depth analysis and graphs over on TB.
Generally, for my mid-rich fingerstyle prerefence, I have all three around 2 o'clock, and leave the para flat. If the room is boomy, I'll roll the low para right down to 30Hz and pull it back a few dB to taste.
Some else will post up their completely different but just us useable EQ settings, no doubt.