I just purchased a 3-channel Dual Rectifier brand new about a week ago. I've been fiddling around with it at real low volume levels, at it's late right now, and I've noticed something really strange. It seems that when I'm in Modern mode on Channel 2, my Presence control works backwards. If I have it all the way down, I get a really harsh, nasty sound. When I have it maxed, there's hardly no high end at all. It seems to work correctly in Raw and Vintage mode on Channel 2, though. Any ideas!?