I have [del]two[/del] one Sadowsky onboard preamp available, recently removed from a Metroline bass. It works perfectly and is nearly new. 4 pots: volume, blend, VTC, bass boost / treble boost stacked. Inlcudes battery clip and output jack. Wired except for pickup and ground connections. *** NO KNOBS are included in this sale. *** $150 including shipping in USA lower 48, other locations ask me for a shipping price.