I was not satisfied (is anyone?) with the overall tone of my Curbow, so I bought a Bartolini p/u (yes...I know it already had a BART...but the MK-1 is NOT the same as a production Bart) and NTMB preamp and had it fitted here in Panama City, FL. by Leitz Music.
There was a problem in that the push-pull Mid-pot was too tall to fit properly in the cavity with the cover plate on. I asked my tech to just fit spacers on the cover...and Voila!
The sound is HUGE....deep...rich...THICK....versatile, etc.
I was able to immediately get thick P-bass tones, or roll the mids up and get jazz tones....and everything in between. It plays soo sweet.
The drawbacks are that the slap switch is rendered inoperable but my tech put a small non-discreet plug in it so it looks very professional.
I simply love this bass...and the NEW tone it brings out!
My other basses include an 81' Rick 4001, and a Geddy Lee Fen JAzz.
Cheers...
Bruce

Cool Bruce, USA made Barts can certainly make a substantial difference in any bass! Peace!