Gentlemen....if you look at the bottom edge, just below the bridge, on your Jazz basses you will see numerous circular objects - from here on called "knobs" - various sizes and materials but they all serve the same function .
Well, if you rotate these "knobs" you'll generally find that they change the sound or "tone" of your instrument, thus refuting the claims of the OP that "they all sound the same". Your own Jazz bass can be made to sound "different".
If the assertion were true I would sound just like Jaco and would have no need to spend time and money in an effort to sound like Mr Pastorius (deceased).
That being said, anybody interested in my Overwater Custom Jazz??