K&K Big Shot

I ordered a K&K Big Shot pickup for my DIY hollowbody fretless bass . A couple of days ago I got it from Thomann and started to test it in various locations.
The manual recommends placing the pickup close to the bridge.
After a lot of fiddling with double-backed tape all I got was low output or terrible feedback and a harsh, trebly tone. Then I tried wedging it under the bridge (floating wood bridge), with a piece of thin felt.
WOW! Now its both loud, as loud as the Hofner-style pickup in the neck position and sounds lovely. Now I even wonder if I really need a magnetic PU at all, but there is already a hole in the top...
If I hadn?t been possible to fit the pickup in this way, I would have had to get a preamp to boost the signal, otherwise it would be useless.
For my purposes it would have been better with an ordinary output jack
that could be permanently installed in the body of the bass, but I understand why a multi-purpose PU like this one has a one-piece molded jack.