If you have a ground loop, this device will almost certainly take care of it. I introduced one whenever my cable TV box was directly or indirectly connected to my preamp. No amount of adding or lifting grounds to or from the CATV coax would change the introduced hum. This Ground Zero fixed the problem in about five minutes.
The standard Ground Zero package includes four 5-foot cables and two 8-foot cables. This package includes an additional two Ground Zero 5-foot cables. I had some long runs and DIY'd three 13.5 foot cables. I am including those as well.
Ships in original box (I did write on the box front what I had stored in it) with original manuals and settings chart (unused). Buyer pays actual shipping plus 3.5% PayPal