The OBP-1's boost-only design gives you the tone-shaping benefits of active electronics without losing the inherent sound of the instrument. The OBP-1's discrete, all-FET circuitry features up to 18dB of boost at 40Hz and 4kHz, creating a sonic environment high in dynamic headroom and low in noise.Aguilar preamps have high headroom, low distortion and reproduce the full dynamic range of your instrument. These are the "Aguilar Sound" in an affordable, easy to install package. A great upgrade for any bass!Get yours today; with the security of our many decades of experience and Sam Ash Direct efficient order processing, your satisfaction is guaranteed!SpecsAll FET designTwo bands of boostMaximum amount of boost: 18db, occuring at 40 Hz for the bass, and 4kHz for the treble.Input impedance: 1 meg ohmOutput impedance: 600 ohmDimensions: 0.98W" x 0.98L" x 0.59D"Three year limited manufacturer warranty