I have a Carvin LB70 with a jazz and a MM pickup. The active circuitry went out on it,Carvin sent me another one. I got it installed and it hummed some even when I had just MM pickup on. I bought a new amp an Ampeg 100w. A friend suggested that I try the amp out in another room in my house. I did it didn't hum as much. A friend of mine owns a Carvin,he replaced the pickups in it with Bassworks? pickups. What are some good pickups for the bass,I am thinking about replacing them. How much are pickups. Should I have posted this in another place? I want this bass to sound like my friend's. I want it to be louder.