Thank you everybody, your answers helped me well. When I will buy'em, I think I will make it done by a tech, I'm not afraid of soldering or whatever, cause I like it, but the tech offers me the warranty of a well-done job.
For the alternative active pickups with the same plug than EMG, I eard about'em but I'm not very interested.. I really want to change mine for passive ones.. On an ENGL Powerball, I thought the Warpig set could sound very great..
(I'm sorry for all the grammatical mistakes I may done, I'm a 17 years old french boy and thatīs quite hard for me ! :lol:)