I just purchase a 1998 Jazz Deluxe. Pretty good sounding bass, but not spectacular. I think I've read of people here replacing the preamp with a Bartoloni or Aguilar. Does this help to open the sound up? I'm actually surprised at the lack of treble coming out of this bass. I suspect it might be the stacked humbuckers which don't have the same bite as the original single coils of the standard jazz bass. I don't think I'd want to replace the pickups as I do like the quietness of the stacked humbuckers.