One Control Minimal Series AB Box

This was to be a simple device with a simple task. It does its job but it also finds static interference that no other device in my studio are capabel of. I have wired it directly to a ground lug in my wall socket, witch is an old trick I often use to get rid of noise. And it works almost every time. But not this time. No matter where I place it or how I connect it this POS creates a background noise that is allways on and it cuts through in the mix. Hopefully I am the only one that suffers from this problem.