The OBP-3 is Aguilar’s most flexible onboard preamp design, providing +/-18dB of cut and boost at 40Hz, +/- 16dB of cut and boost at either 400Hz or 800Hz and +/- 16dB of treble cut and boost at 6.5 kHz. The OBP-3 has multiple wiring options, and can be wired with either a push/pull pot OR mini-toggle for midrange frequency selection. OBP-3TK/PP: Includes separate Treble, Mid, and Bass pots. Mid pot is push/pull for Midrange frequency selection