Well, I had a first-time and scary experience at a rehearsal this weekend...For the first 20 years of playing, then the last 2 years, this has NEVER happened to me...
My Jazz bass has the Aguilar preamp in it, which I've never been terribly crazy about, but it got the job done while I saved my pennies for the Nordstrand preamp that I really want for it.
However, at this rehearsal, I pulled out my Jazz, started to warm up and, hey, what's wrong with this thing?? Doesn't sound right at all. Even with the blend pot in the center, it had way too much rear-pup sound. Nothing like a Jazz bass (both pups at 100%). I looked at it and looked at it (even replaced the 3-week-old batteries, which I don't usually replace for 3 months), and finally determined that the blend pot must have gone bad. Further examination revealed that both pups were fine, and the rest of the preamp worked properly, but still sounded really bad. And I was 45 minutes from home, so it was a really long rehearsal with my Jazz not working properly.
However, Saturday and Sunday night, and a rehearsal yesterday, I totally disproved the notion that a Precision can't be funky...
So NOW, I'll be carrying my Precision along as a spare. I should have been all along, I guess. If had been on a show with this problem, it would have been bad. REALLY bad.
Today, I order the Nord preamp I wanted and a blend pot for the Aguilar. It's going in my fretless Jazz.
Now more than ever, you are never too old to learn...