High tone at record

try unpluging your monitor jack from your computer..do you plug in your speakers to your computer for music(itunes and you tube)if so...unplug that other cable that works off your internal soundcard(for windows,relteck,exc.)
look for a ground problem.you need a good ground to run this unit.it seems to pick up interefernce easily.if all else fails buy a small three prong ground adapter.