Here's the deal, since I played a really loud gig (I really pushed my LMKII +2x10 to the limits), the fan on my LMKII head seems to be louder than before. It's hard to compare, because I never really paid attention to it before, but the fact that I am paying attention to it now means something has changed. It's not a problem on stage, but I don't like it. Can this be caused by pushing the amp? Or are there other possible explanations for this? Dust maybe?