I'm currently playing a 98 Thumb BO 5 string with the 2 band MEC II preamp. I've owned the bass for going on 11 years but I'm looking for a bit of a change up. I've been playing a buddies' passive Carl Thompson with Kent Armstrongs in a V/V/T configuration (I think they are humbuckers but could be soapbars). The pups seem to have a really hot output in comparison to the Thumb. The bass just sings with a lot of clarity and a bell like tone, even on seemingly older strings. It's what I'd expect from a CT and I credit construction as much as I credit the pups. The 'Wick on the other hand seems to be very flat and somewhat sterile sounding in it's stock configuration in comparison with the CT (admittedly it's probably due for a fresh battery and a string change). My thought is to replace the preamp with a passive system. A friend suggested doing a volume/4way rotary/tone setup. The rotary would select neck only, both series/ both parallel, bridge only. (I think this is a Dingwall setup). The other obvious setup would be V/V/T like a Jazz Bass but wire in such a way as to cancel out the hum you get when you don't have the volumes set in unison (wired in parallel?). I'm also thinking about replacing the stock pickups with high output models, or having pups custom wound and using the existing MEC II PUP covers,...likely going with a humbucking pup in a single coil format. What I'm looking for is a system that takes better advantage of the pickup placement and the inherent growly tonal qualities of the Thumb but giving it a stronger and less clanky/brittle top end. The current active preamp seems to stifle the basses potential and I feel like going to a high output passive system would open the Thumb up and give it a livelier tone. I don't really have any skills but I have a friend that is willing to work with me on this project and he is who I'd go with to custom wind the pickups. Opinions and suggestions are requested and pointing out any flaws in my logic is appreciated.