I currently use a evh 5153 50 watt head plugged into a 100 watt crate with a gi2k100 speaker. I also use a jackson dx6 which i just put a duncan pegasus in bridge. Im trying to find a good tone but would also like to hear what some others with the same amps settings are. I play mostly metalcore and thrash. Im tuned to drop c using 11-54 strings
Best advice I can give is to try an EQ pedal in the effects loop. You already should be getting excellent tone with that rig (at least I thought so when I plugged directly into an EVH 5153 50 watt). But an EQ allows you to personally tailor your tone in ways that can't be accomplished with the amp's EQ alone. I have 6505 and 6505+ heads which are similar to yours-- but it's my MXR 10-band EQ that helps me get "my" tone.
Atmospheric dark metal w/ black and death metal influences:
(My Soundcloud page):

Pestilential Flood
You see those knobs on your amp? Turn them, play a chord or a lick, and if you don't like how it sounds, turn them until you do.

EDIT: That was a little snarky. What I mean is, tone depends on a lot of factors, and it's extremely unlikely that anyone, even running the same setup, would use the same settings that you would find pleasing to the ear.
Last edited by imgooley at May 20, 2017,
I find it best to max the tone knobs or put them in the middle on amps with passive eq, then roll back or turn up what I need. For example, too much treble? Turn it down. Not enough bass. Either turn it up or turn down the the treble and mids.

There is no magic settings on any amp. I love my amp, but when someone else eq's it to their taste, I usually dislike the tone.

So set your tone either max or in the middle and make small adjustments as you play, say half a notch at a time, and you will find YOUR tone.