Then when you put a wire between the input of the filter (on the RCA connector) and my sled all the noise is gone... I apparently have a voltage difference between my sled and my RCA connectors.

Not exactly... that's not a voltage difference, that's a ground loop.

You didn't say whether your Empeg is a Mark1 or a Mark2. If it's a Mark1, what you describe is normal and the player should have included grounding leads to handle that very situation.

If it's a Mark2, you've got a ground loop because of a differential in ground potential between one or more of your system components. You haven't detailed your system architecture, so it's hard to say where the problem might lie. Check out the following documents on how to resolve noise issues in car audio installations:

http://www.installdr.com/TechDocs/999501.pdf
http://www.installdr.com/TechDocs/999502.pdf
http://www.audiocontrol.com/techpapers/tech1002.pdf



___________
Tony Fabris