Hadn't had my Sire no more than about 3wks. And I've not yet spent a great amount of time with it to find out all the sweet things I feel it's capable of. But I did notice when I'm switching from front to back pickup. And I leave it in either position, there is a real strong humming noise be it in the neck position or bridge when I'm using the blend knob. Any idea's of what's causing this.