Today i was trying out a Mesa Boogie Mark IV at my local guitar store and i couldn't get a nice crunchy tone that wanted such as Metallica/Lamb of God. I realize it takes a lot of time to get a good tone on that amp because you can tweak so much but i still got no where. Whoever owns or tried the Mark Iv can you please steer me into the right direction on what to do. (How high the bass, Eq etc. must be). The Mark IV will only be at my local music store for a month and then it will be shipped back to where it was before so help would be appreciatated so i can decided what to do with the Mark IV since i heard it's one of the best amps out there. Thanks.