I too was skeptical that the replacement of the original power cable for a TEAC NT-505 (DAC/preamp) would impact the sound quality of my stereo. After all, the owner’s manual explicitly said not to change it or risk fire or something. With the aftermarket power cable in place, the sound quality improvement was remarkable and, so far, no burning or fire. The noise floor dropped dramatically and I found myself listening at higher volumes than previously. At times, the speakers, Revel F228Be’s, seem to disappear which I had not experienced before but had heard others describe.
I probably shouldn’t have been skeptical as my wallet had just suffered through two other replacements: Blue Jeans Cable Canare L-4E6S XLR cables and a highly Amazon rated $15 USB cable to other cables. I fear additional catastrophes involving the original power cable for my Parasound Halo A21+ and my Blue Jeans Cable Belden 5T00UP speaker cables will be next.