hum
That hum could be coming from anything. Is it coming out of the speakers or out the chasis of one of your pieces of equipment? If its the speakers you may just have a power line running parrell to your speaker wire, if its from the a unit. Well chase down the sound, its more than likely coming from the transformer. That's a pretty hefty repair if its not under warranty, but you need to tell us where its coming from... the Monster power won't do anything, it'll just give you a cleaner 60Hz hum...ha.