Ok so i just purchased a Marshall 1987XL head. But the problem is i can't not dail the thing in to even sounding decent. On the treble channel everything is icepicks high no matter what the knobs are on. The normal channel is better and i can get a nice crunch on it, but it has a rather large bass to that i can't get out of it. Is it just a matter of breaking it in? I have never had a amp do this to me. Did i just get a dud or something. I am playing a tele straight into it as of right now. If you have any settings that could get me on the right track that woul be great also.