As the title says, I'm having trouble with my neck Seymour Duncan Jazz pickup - it sounds muddy and loose under hig gain, specially after 12th fret in lower strings. I have tried to lower the pickup and raise the poles. it helps a little bit, but still isn't good because the pickup starts loosing power. Do you guys recommend any other pickup to replace the current one? Or perhaps I have a bad pot? My guitar does not have a tone knob, only volume. I play mainly hard rock and heavy metal, I have a Duncan JB at the bridge position. So I'm not considering ceramic pickups, only alnico. Thanks!