Sadowsky Onboard Bass Preamp, Onboard Bass Preamp (4-Knob System), Prewired onboard bass preamp for J-style basses, With a metal control plate, Active preamp for passive pickups, 4-Knob Layout with controls for: Master Volume / Balance / Vintage Tone Control (P/P) / Treble and Bass (stacked), Push/Pull function on the VTC control for preamp bypass, Can be installed with either the included control plate or with an electronics panel, Frequency esponse: 5 - 50,000 Hz, Bass control offers +18 dB boost at 40 Hz, Treble control offers +18 dB boost at 4 kHz, Total harmonic distortion (THD): 0.18% at 1 kHz, Input impedance: 1 Mohm, Output impedance: 1 kohm, Powered via a 9 V battery (not included), Power consumption: 9 mA, Installation depth: 29 mm, Dimensions of motherboard (L x W x D): 30 x 21 x 25 mm, Up to 870 hours of battery life@+*Note:* Register your instrument at www.w-distribution.de/Warranty to extend the warranty to 4 years.@+@+