WJA-3B 3-BAND All-in-One Jazz-Style Control Plate
ONBOARD BASS GUITAR PREAMP
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With Selectable Low, Mid, and Treble Frequencies & Stacked Volume / Pickup Blend knob
After years of experience with various onboard preamps and a special request from Marco Cortes at Marco Bass Guitars, I decided to create my own onboard preamps.
for best audio experience, wear headphones
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KEY FEATURES
The most significant difference lies in how companies typically set their EQ frequencies and bandwidth, particularly for the low end. Utilizing the proven WJBP EQ design method, I’ve crafted an onboard preamp that stands apart.
- Stacked Volume / Pickup Blend knob
- Treble control with 6 kHz / 10 kHz switch
- Mid control with 350 Hz / 600 Hz switch
- Bass control with 44 Hz / 80 Hz switch
- Active / Passive mini toggle switch
- Runs on single 9V or dual 9V (18V) for more headroom
- Includes both 9V and 18V battery cables
INSTALLATION
Fits most Fender-style Jazz Bass cavities.
Recommended: increase cavity depth by 2–3 mm for optimal fit.
Some models may require minor routing adjustments.
CAVITY REQUIREMENTS
- Min. Length: 145 mm
- Width: 32–35 mm
- Depth: 35 mm (add 1–2 mm if battery inside cavity)
We highly recommend external battery compartment(s) for ease of changing batteries.
PLATE SIZE
152 mm × 70 mm (widest point), 2 mm thick
PRE-ORDERS OPEN NOW
Limited to 100 units – don’t miss your chance to own the first edition.
**PRE-ORDER NOW FOR EARLY OCTOBER SHIPPING** Visit Shop ➤
This preamp is the result of meticulous design and testing, built to meet the demands of discerning bass players. Whether you’re recording, performing, or exploring new sonic possibilities, this preamp will bring out the best in your bass guitar.