Well, I'll jump into this old thread.
When I took up the bass again after many years laying out, the first instrument I got was a Jay Turser five string EAB. It was an early one, made in Korea - excellent playability, well-balanced, and very handsome to look at.
Right off the bat, I got rid of the crap strings it came with and put on some Dean Markley phosphor bronzes which improved the tone considerably, although I hated the sound of the under-the-saddle piezo pickup. A new set of Gotoh tuners solved tuning issues.
Tone was somewhat improved when I invested in a set of K&K Pure pickups from Mr. Gollihur; as did bypassing the crap Belcat preamp that was built into the instrument in favor of an outboard Electroharmonix LPB-1 and my trusty old TAPCO rack graphic EQ in front of the amp.
I put in a "feedback buster" (a rubber plug that fills the soundhole) and was almost there, but not quite.
One day I idly took the Dean Markley pickup out of my beat up old acoustic 12-string and popped into the bass - whoa-wa! That was what I was looking for, but the bronze strings had to go, so I put on my favorite D'Addario Nickel 1/2 rounds, and that did the trick. I had my sound and playability.
I don't play it much, but when I do I play it straight through my 50-year old Ampeg Rocket amp, and it sounds great!
J