Can anyone familiar with the orginal setup give me the skinny on the tone knobs? They don't roll off the high end completely like a normal tone knob would. The knob towards the bottom has a more audible effect on the overall sound: when rolled off the single coils sound very glassy and mellow. The tone gets grittier as I turn the knob up. The middle knob is very subtle, I can't exactly determine what it does but it also affects the tone a little bit.. What are they and what exactly do they do? The middle control is a SPC or "fat control" Sounds like the battery needs changing as this provides a 10-15 db boost of the midrange. The third knob is a regular, passive tone control rolling off the high end. Remember, with active EMG's, they behave a bit differently than passive pickups. Use an alkaline battery for longest life.