I have a quick question on the EQ on the Peavey Minx 110. In the manual it says that the bass mid and treble are passive controls. Does this mean that the only thing they do is cut at the designated frequency? If so, then to set the amp "flat", you'd have to turn the controls all the way on, right (all the way clockwise)? If not, how do you set a passive EQ flat? Thanks!