What a relief - did the job 100%!
I live in a 100 yr old house and have a small home studio setup. Never had noise in it before, but after I moved here, I had so much hum and crackle that I could barely use the monitors and was stuck with headphones, which were a bit better as powered through the computer. It was my main home stereo too, so blah. I had an electrician check the place before I bought it, and he confirmed there are grounding problems. Fixed everything that might risk my safety, but can't afford a $3-5K home rewire. Problem - even on headphones still had noise with my separately-powered condenser mic, and you can forget plugging my little Pignose into the wall, stuck on battery.
TRIED several other products - cheaper ground lifts which didn't do anything. Also my powered sub has a ground lift internally, but that didn't do anything but change the tone of the hum. So I finally broke down last year and forked out for this M8Dx. I figured, might not fix the problem, but can always send it back. And the price was better than I'd seen before. VOILA! There is not a peep on my quiet lines, speakers, headphones, mic, whatever. Changed my whole situation!