The pickups that came with the bass were not Thunderbird pickups. They were split coil Precision style pickups crammed into a 4 string case. The bass had a wonky sound and the B string was weak. Mike installed his T5 pickups. Thunderously awesome. The bass came with a stack knob arrangement. Mike told me the pots were the wrong value and contributed to the poor sound. Changed out the pots to 500k ones. Changed the controls to V-V-T and installed a side jack. The bridge was originally a Badass style knock-off that would not intonate correctly. Installed a new Hipshot Bridge. The nut was very rough. Mike refiled and reshaped the nut. The bass played stiff, if that makes sense. It just felt tight and like it was fighting me. Mike gave it a nice Lull set up and now it plays like butter and sounds like thunder! I am very happy with the bass now. In hindsight, I should have gone with one of Mike's PT5s. Lesson learned. I should add I have a thread on the Bluesman Vintage Club here on TB that details my trials and tribulation with this build, if any of you are interested.