He runs a few of amps for the tone, active EMGs, a few pedals but mainly a lot of years playing and technique behind him.
If you can find it, theres a live metallica concert from 2006 at rock AM ring online. Near two hours long from German MTV and his tones are fantastic and hes got a good portion of the mix too.
EDIT - in fact the very concert I mention is the one where the orion video is from.