The Sadowsky Onboard Bass Preamp (4-Knob System) is a pre-wired system that offers the same controls and legendary active preamp as all Sadowsky basses. The preamp is designed for installation in most basses with a 4-knob layout. Newer active models with a 4-knob layout, a side-mounted output jack, and a battery compartment typically require no modifications. For passive instruments, the only necessary change is to relocate the output jack to the side of the instrument and make room for a battery. The controls are: Volume – Pan (Balance) – VTC (Vintage Tone Control) – Treble/Bass – Mid Boost switch. The Bass and Treble controls boost the signal exclusively; turning them fully counterclockwise results in a linear frequency response. The preamp also features a 500 Hz mid-boost, which can be engaged via a toggle switch. The VTC control is passive; its maximum setting is a flat EQ. The further you turn the control down, the more the high frequencies in the signal are attenuated. This system is not compatible with active pickups that require something other than a 250K or 500K volume or balance pot.
- Pre-wired onboard bass preamp for electric basses with 4-knob layout, 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 (Tandem) / Mid Boost switch
- Push/pull function on the VTC control for preamp bypass
- Includes a 0.1 µF replacement capacitor for the VTC module for improved high-frequency attenuation when used with Sadowsky soapbar pickups.
- Longer cables between the potentiometers to ensure installation in basses other than Sadowsky basses.
- Screw terminals on the balance potentiometer for solderless installation of the hot and ground cables of the pickups.
- Without Control Plate
- Frequency range 5 Hz - 50 kHz
- The bass control offers a +18 dB boost at 40 Hz.
- The Mid Boost switch provides a +10.6 dB boost at 500 Hz.
- The treble control offers a +18 dB boost at 4 kHz.
- Total harmonic distortion (THD) 0.18% at 1 kHz
- Power supply via a 9V battery
- Current consumption 9 mA
- Up to 870 hours battery life
- Input impedance 1 MOhm
- Output impedance 1 kOhm
Note: Defects or damage resulting from improper installation or the use of unsuitable accessories and tools are excluded from the warranty. This includes overheated solder joints, incorrect solder, and resulting damage to the electronics and solder joints.
Note: When installing a Sadowsky onboard preamp in a MetroExpress bass without a control plate (Modern, Verdien White, and M/J models), the holes in the body for the potentiometers must be enlarged. This is because the factory-installed potentiometers of the MetroExpress have a smaller diameter than the potentiometers of the Sadowsky onboard preamp.