Ok attaching a ground wire from the chassis to the ground screw on another power outlet in my rack produces the hum. This is actually a good thing because I know that the screw I selected is indeed going to ground so the noise is working with me here. So HERE is what I did instead. I ran the ground wire from the chassis on the Power amp to the ground post on the pre amp and BINGO no hum... only that very faint sweet soft white noise hiss I was expecting. Problem solved! feel like dancing. I think that the ground loop is being cause by the only two components that I could not unplug to test with...the power amp and the pre amp lol. Thanks again Yogiboy.
Keith
Keith