The Sadowsky Onboard Bass Preamp (4-Knob System) is a completely prewired system offering the same controls and the same legendary active preamp as all Sadowsky basses. This preamp is designed for installation on most basses with a 4-Knob Layout. On newer active electric basses with a 4-knob layout with a side jack and a battery compartment, usually no modification is required. On passive basses, the only required modification is to move the output jack to the side of the instrument and to make room for a battery. The controls are: Volume – Pan (Balance) – VTC (Vintage Tone Control) – Treble / Bass. The treble and bass controls are boost only - flat response is with the controls at their complete counterclockwise position. The VTC control is passive, the maximum setting is a flat EQ. The further you turn the control down, the more the high end in the signal will be attenuated. This system is not compatible with active pickups requiring anything else than a 250K or 500K volume or balance pot.

- Prewired onboard bass preamp for electric basses with 4-knob layout, 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)
- push/pull function at VTC knob for preamp bypass
- 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
- 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