At the risk of seemingly repeating last year's answer, it's this. Not the bass but, rather, the Sadowsky onboard preamp I installed. After a little bit of woodwork, it's never fun putting new holes into old basses, it has turned a great playing instrument with quirky and complicated electronics into an absolute savage which plays and sounds as good as anything I've ever had. Rather than have a small hole or non-functioning switch, I set the switch up to run the pickups as serial/parallel which has added another nice option to a great, great bass.
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Before