The Aguilar OBP-2 2-Band Bass Preamp is a great way of improving your tone and giving yourself more control over your sound. The OBP-2 lets you boost and cut bass and treble frequencies, without ever getting too harsh or distorted- the legendary Aguilar sound. +/-18dB of boost and cut at 40Hz and +/- 16dB of treble boost and cut at 6.5 kHz gives you a large scope for tonal variation.Available with separate treble and bass pots or a single stack treble/bass pot.