I installed them in my Cort C4 plus with Nordstrand Fat Stacks to replace the bartolini Mk1 pickups and Markbass preamp (nordstrands are a bit shorter for 4-strings).
First time failed as it didn't work in active mode and with electronics, it's difficult to tell if I broke it, it was already faulty or I made some mistake, but Thomann solved it for me by replacing them after I sent them back.
The new set works great, knobs are good, control works good and it sounds great. As a bonus, the active/passive is a push/pull, so I could coil-split the fat stacks with the extra switch of the C4.
The jack is plasticky and very short, so I didn't use it.
Connecting the battery+ and ground on the bass-circuit is a bit fiddly, so extra wires (like for the signal and ground on the volume) would help for us non-professionals.
The schematics are simple enough and useful.
I would have preferred the nuts and washers to be in a separate bag instead of together with the electronics.
Doesn't work well with the rechargeable batteries I used as it gives a hissing sound, no problems with one-time batteries.
