The BOSS ODB-3 is an overdrive stompbox for bass players that is well-built and affordable (99 € on Thomann). The most desirable feature is the blend knob that retains the bass's characteristics and bottom end.
A common complaint, however, is that it is too gainy for an overdrive and tends to have harsh, "fizzy" highs (even with clean signal blend > 50%) which makes it sound and behave more like a fuzz.
I modified one according to Brian Wampler's suggested improvements that should give the clipping a more natural feel and tame the shrill highs.
After the modifications it has a punchier and slightly driven, fat bass tone that reminds me of the BOSS Bass Driver BB-1X, which is 50% more expensive than the ODB-3.
I briefly had a new stock ODB-3 pedal available for comparison and shot this video:
The knobs on both pedals were set the exact same to demo the modification's impact. To me it sounds more pleasing now. I might do further videos in the future and play around with the settings to show how useful it can be. Stay tuned for this and other guitar and bass videos.
If you're interested, here's a forum link to the Wampler mod details by the man himself:
http://www.diystompboxes.com/smfforum/index.php?topic=83870.msg698445#msg698445