(718) 433-1990 — custserv@sadowsky.com

Sadowsky Onboard Bass Preamp 4-Knob


The Sadowsky 4 knob Onboard Bass Preamp is a completely prewired system offering the same controls and preamp as all Sadowsky Basses.
VTC=Vintage Tone Control (pull up for total bypass).
The preamp can be installed with the included control plate or mounted through a rear control cavity in either a 4 in line or diamond pattern.  Pickups attach via solderless connectors at the pan pot.  Direction of the pan pot can be easily reversed by which pickup terminals are used.  Installation requires a side jack and a battery compartment.  We recommend shielding the control cavity and pickup cavities at the time of installation.  We recommend installation by a professional guitar technician or builder if routing and drilling for a battery compartment and/or side jack is required.  This system is not compatible with EMG or any other active pickups requiring anything other than a 250K or 500K volume pot.  For these applications, please custom order a parts only preamp kit and use your original volume pot.

Additional information

Weight 0.8 lbs
Dimensions 9 x 4 x 4 in


  1. Michael O’Brien

    I purchased the “drop-in” Onboard Bass Preamp about a year ago based on having purchased previous preamp kits from Sadowsky Guitars as well as having owned several Sadowsky basses since 1996. Have been playing bass for 50 years, and because I’m a Sadowsky fan, I’m admittedly biased. This said, for J-type basses, the drop-in preamp is a brilliantly conceived and executed product. The installation was as much a “no-brainer” as this (perhaps cliched) term implies. I swear you could attach this preamp to a strung 2×4 and get good results. I put mine into a fretless “Frankenbass” made up of parts I’ve had laying around (Sadowsky pick guard, older Fender J-bass body, All-Parts lined ebony neck, Hip-Shot brass bridge, Lollar J-PUs). The results are stunning. I feel completely comfortable saying that I can wholeheartedly recommend this peramp to anyone looking to upgrade a J-bass (or a 2×4). Best regards… Michael

  2. Joelio almeida

    Hello , I have a bass Tobias Renegade uses and the circuit malfunctioned no gain , I need to know if this preamp from Sadowsky it works with Bartolini pickup , and how much is shipping to BRAZIL Cep 71200-030

    Olá , Tenho um bass Tobias Renegade Usa e o circuito apresentou problemas no gain, Preciso saber se este preamp da Sadowsky dá certo com captador Bartolini, e quanto fica o frete para o BRASIL Cep 71200-030

  3. STEVE FURR (verified owner)

    I am a bass player and a craftsman with limited electronics experience. Not a Luthier. However, I installed this preamp into my Jazz Bass with great success. There’s a wealth of info on YouTube for this kind of work. My JB sounds awesome!

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