Just found this thread and website via google..
Really interesting reading, luckily my FB383 Freebass is working fine. Nice to know what to look out for though.
Im actually posting because ive borrowed a MB33 mk1 (black/silver) from a mate and have been comparing it to my FB (orange/silver)
It seems the filters are different.. (or at least calibrated differently)
The FB filter does not reach as far down and doesnt open as much as the MB.. resulting in it sounding duller with no resonance set.
But the MB resonance doesnt go as high and filter envelope doesnt open as much as on the FB.
With full resonance the FB sounds much brighter and filter envelope snaps more aggressively.
Im just wondering if anyone else has noticed this?
Does anyone know if these things can be changed by tuning pots inside?
Or do they use a few different components?
Im more curious than anything