Hum From Speaker

1. I hear a low Hum from my speakers.
2. When I increased the volume the Hum does not increase.
3. I disconnected everything from Amp except the speakers and I still hear the Hum. Not even the interconnects were connected to the Amp. Just the Amp plugged into the wall with a cheater plug as a test.
4. All other components were disconnected from the wall.
5. I can't hear any Hum from the Amp unless I put ear right on the Amp.
6. My Amp is a Sunfire 5x200

Does not seem to be ground loop.

Any Ideas? Any Solutions?

Thanks ahead of time.