I don't have a clue on how is this kind of sound achieved. It almost sounds like slap, but I'm pretty sure it isn't. Can you get it with a jazz bass, or is it a special kind of instrument?
i know duff uses a galien kruger amp, and cab. in the studio,and live he blends two signals a dry one, and than he plays through a chorus. the slap sound your hearing is due to the fact that they're new strings, and he plays really fucking hard with a pick. i know that sounds simple, but i think that's it.