I generally mess around with presets with the axe edit, today I didn't have the computer with me and on the axe fx amp page I discovered a bright knob (I'm on 16.4). When was it introduced? How does it work? I'm in the middle of a tour and was actually looking to get some more sparkle out of my dual ac30's preset.. What's the difference between turning up the treble and turning up the bright parameter? If I were at home I'd just experiment myself, but being in different venues with different PA's, different wedges etc, I'd like to know the difference in theory before I make adjustments.