For EMG pickups only. This system features a pre-wired balance control
(blend), master volume, separate bass and treble pots along with the
concentric/stacked mid-control. All the EQ controls and balance control
feature center detents. This active EQ circuit for bass guitars works by
rotating the control clockwise to boost, counterclockwise to cut. There
is a center detent for flat response. The mid-range control has a
variable frequency knob that allows you to sweep through the
mid-frequency range from 100Hz to 1KHz. This selects the frequency to
boost or cut.