The UNI-PRE 3 Knob is a new generation bass preamp system from East UK. It’s a brand new design that sets new standards with unique features, designed to fit virtually any bass which has 3 knobs with rear cavity electronics. But note it also requires a toggle for active/passive switching. The modular construction makes for easy installation, with simple plug connections between modules. External wiring, such as pickups and power, are simply connected using screw terminals.