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
My monoblocks are 3 prong grounded plugs, preamp is two prong ungrounded, as is DVD player, cable box, TV. It is a static noise, not a ground loop low freq hum. Bad op amp? Preamp going bad, it is an old unit from the early 90's. I will be getting the sanders sound preamp in a few weeks, I'm praying it is the preamp.

All plugged now into a furman pl-plus C conditioner.

I had my other odyssey monoblocks hooked up to same upstairs set up, and sound Was still audible. Moved B&K pre upstairs, same noise. Basement setup now has odyssey amps , B&K pre, no noise, only sometimes. Maybe I'll check to see if the furnace is on, when I hear the noise. I'm at a loss as to what it is, I'm hoping it's the preamp, needs to be retired anyway.
I leave the power off on the preamp when plugging in the cord to furman. I have had the power off, on, tried a different outlet, tried a different outlet with another power strip/surge protect, to no avail once the onkyo plugs in the ticking/static, similar to a light snare drum tapping the skin, driving me nuts.

I also think some of the hdmi may be causing it, but on a much less noticeable scale. When I unplug some of the hdmi cords from the back of the tv, it changes sounds in a very small way yet again. SON OF A..........

I'm out of my head.
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 ??????