A good Metal sound can depend on a few things - The way I tend to get a sort of A7X like tone is - (this is with my Strat) :
1. Bridge pickup on guitar
2. A decent amount of Gain but not drowning in it - maybe about 3oclock position?
3. Half way on Mids
4. Half way on Treble
5. a bit less than half way on Bass
One crucial thing for me is to use a Compressor with a decent bit of Attack & Sustain - this really helps with the whole SYN like sound.
I notice that with every amp my settings will differ, so I'd imagine it will be the same with a different amp & guitar - it's pretty much all pertaining to your ear! You'll probably tweak it around until your ear likes it