The OBP-3 Aguilar 3-Band Boost/Cut Onboard Preamp is Aguilar's most flexible onboard preamp design, providing ±18 dB of cut and boost at 40 Hz, ±16 dB of cut and boost at either 400 Hz or 800 Hz and ±16 dB of treble cut and boost at 6.5 kHz. Supporting 9 or 18 volts, the OBP-3 has multiple wiring options, and is wired with a push/pull pot for midrange frequency selection.