Upgrading a 2003 Squier Jazz Bass

This project began with a well-loved, stock 2003 Squier Jazz Bass, a birthday gift for Ash, who’d owned it for over a decade. The bass had seen better days, with old strings that left residue on your fingers and a constantly slipped out of tune. First up, I swapped in Lollar pickups and installed a new custom wiring harness with CTS pots, a paper-in-oil tone cap and a switchcraft jack, bringing clarity and control to the tone. Next, I adjusted the truss rod and bridge height to fix the action, which was too high for comfortable play. After getting the action right, I replaced the original tuners with Schaller tuners to sort out the tuning instability. Once the new half-wound strings were on, I intonated the bass for precise tuning across the fretboard.

The frets also needed some love, so I gave them a thorough polish and conditioned the fretboard using Monty’s Montypresso. The owner had picked a mint green 3-ply scratchplate for the refreshed look, and I had to drill new holes to get it to fit the body. Along with tele-style knobs, it was a nice, subtle visual upgrade.

Having played in the band with the Ash since then, I can say it sounds great—he mentioned how it’s the perfect mix of the familiar bass he loves and the improvements it needed.