Here is a shameless plug for Steve & Jill Azola - several years ago I bought a floating top bugbass second-hand. After changing strings, the E tuner developed a buzz. I contacted Azola and they sent me a new tuner. That, however, didn't fix the buzz. I contacted them again and Steve had a few ideas to try, but that still did not fix the buzz.
So again I contacted them and Jill sent me a couple of other tuners to try as well as a couple of t-shirts and stickers (that I had asked about earlier). I changed out tuners and PTL, the buzz was gone!
I am very impressed and thankful to the Azolas. Bearing in mind that I am not the original purchaser of the bass, their follow-up care is exceptional!
And, FYI, with all the discussion of which EUB sounds most like an URB, I have to state that the floating top with hybrid strings has a really nice sound both pizz and arco.
