Sadowsky Onboard Bass Preamp MB4F

Sadowsky Onboard Bass Preamp MB4F, prewired onboard bass preamp for electric basses with 4-knob layout and mid boost switch, side jack and battery compartment, active preamp for passive pickups, 4 knob layout with controls for Master Volume / Balance / Vintage Tone Control (P/P) / Treble and Bass (stacked) / Mid Boost toggle, push/pull function at VTC knob for preamp bypass, incl. 0.1 µF replacement capacitor for the VTC module for improved treble roll-off when used with Sadowsky Soapbar pickups, longer cables between the potentiometers to facilitate installation in non-Sadowsky basses, screw terminals on the balance potentiometer for pickup hot & ground wires for solderless installation, without Control Plate, frequency response 5 Hz - 50 kHz, Bass control offers +18 dB boost at 40 Hz , Mid Boost switch offers +10.6 dB boost at 500 Hz, Treble control offers +18 dB boost at 4 kHz, total harmonic distortion (THD) 0.18% at 1 kHz, power supply via one 9V battery, current draw 9 mA, up to 870 hours battery life, input impedance 1 Mohm, output impedance 1 kohm