FretsAflame
Undercover Shredder
Really all i can say is to totally fuck with your settings. Don't hold anything back when your playing with your dials. When you hit sounds you like, write the settings down, when you find something interesting out, make a note of it. Also, i've found that I can get pretty close to the sounds off of blackwater park (especially The Drapery Falls) by setting the bass on my 5150 to 10, the mids to about 2, the highs at 10, and adjusting the resonance close to 10 (think 8-9) and the presence settings at 7ish (all of theses settings were with a gain of 10). Although to reach such signature sounds that occur on tracks like "The Funeral Portrait" - ie, the really poppy sound in the intro ("ruby eyes in the fog...") you really need a prs. The way the prs is configured and the pickups they engineered are key to that sound. Just remember if you want that smooth-blended gain jack up the bass, but don't forget to add some highs in there, and pickup settings do matter, otherwise it comes out as sludge-filled bass with no definition. Hope i helped, or at least gave you a start!