Static from tweeters, preamp?

I get audible static from my tweeters upon plugging in my onkyo p-308 preamp. Bad power supply, bad capacitor???? Poor solder joint?

There is very minor static, when preamp is unhooked. I plug it in and the static gets louder, much more noticeable. From what I remember, by B&K pro 10 mc also does this. B&K has 3 prong grounded, onkyo has 2 prong standard. When I used my Sunfire sig, I had no noise at all. It is a reg 2 prong plug. Help
Two hdmi cables into tv, one from cable box, one from DVD.

Furman has two isolated banks, I plug all components to one side, and only preamp/amplifier into the other. Yes I tried preamp in every possible outlet, as soon as plug hits receptacle, static hits the tweeters
I plug amps into wall outlet, can't hear anything at all.  

I plug in preamp, and there's the static.  Possibly preamp, but maybe my hdmi's cables are touching my rca's from amp to preamp. I rerouted every able , all power cables e together in a foam long tube.  Same sound.  I hope when the new pre comes, I don't have any of this static, I'll . 

I unplugged every very component one at a time, and when the preamp is plugged in, I get static, BUT....... when I turn the preamp on,. The static goes almost away, the volume of the static is cut in half, is going on ??????  
Pioneer dv48 elite was culprit, major static noise,.  Huh, cheap Sony replaced it via rca, no more static, well, a little, enough to live with for now.