None of these options are truly effective for noise reduction, and that’s not really what it’s about. Talking about noise and believing that added equipment can suppress it gives audiophiles a sense of reassurance. You’ll often hear discussions about digital gear, claiming a new product has a lower noise floor and therefore sounds better, but most of the time, noise isn’t the issue—the improvement is due to other factors. The same goes for AC power conditioners. In short, Audio Magic is the best choice among the ones you mentioned. Avoid any serial or transformer-based AC conditioners, use parallel conditioners and more importantly, if you haven’t already, install a dedicated line with solid core wiring. Keep in mind that AC conditioners are designed to sound good, not necessarily to suppress noise, despite what the advertising might suggest. Those that focus solely on noise reduction often end up compromising the speed, liveliness, and power of the AC line. In-line, serial stuff they add and transformers to get rid of noise do that.