Well the headline says it all. I’m exclusively a jazz bass player and this was connected to my emg jx pickups. I didnt want to splice my pickup connections so I decided to purchase this kit. The bass boost sounds plasticky, and the mid sweep has a lot smaller band than other preamps. For a jazz bass the mid sweep should be at least up to 1.8 khz to get the sweet high midrange frequencies to accent your slap notes, at least IMO. The treble boost basically does nothing until you go over 60-70%. My experiences were with 9v supply. Well this isn’t for me but if you’re into more modern sounds and want something thats plug and play I would reccomend it. Also the build quality is superb and it’s very easy to install.