HOW TO TURN OFF NAP TO ELIMINATE WHITE NOISE?

RE: HOW TO TURN OFF NAP TO ELIMINATE WHITE NOISE

Ive discovered that when ever I attempt to record audio in Logic pro 8 I get a constant white noise in the back ground. I've seen proevious posts regarding this and have downloaded the xcode developer tools but cant find the right path to locate the "nap disbale" option. I'm using a mac pro intel 10.6.8 [snow leopard] please advice as I am going out of my mind!!...thanks