I am not sure how to review this as it is working properly when nothing happens! It is also important where you plug this in. I started by plugging it right before the power amp on an extension bar. It actually caused an unexpected noise problem. I then plug it into one of the wall outlets in the same room thinking the AC in the room is connected to the same circuit. The noise subsided but from the level metre, I can see there is still some noise. Then I plug it right next to the power chord that connects my whole system. The system is not totally quiet (so far), I don't really know why but I am sharing this with you and see what your experience has been.