@ pawlowski6132, you asked for specifics, here goes. I've installed a PS Audio BHK Stereo 250 amp recently and have been working to get the tonal balance of the system fine tuned to my liking. I had few power cords to try, none terribly expensive; Mojo Audio copper ribbon, Wireworld Eclipse, DIY Furutech FP-S032N, & DH Labs Red Wave. All made subtle changes but all were slightly off, either too much sibilance on closely miked recordings accompanied by a bit of tonal dryness or a lack of liveliness if they didn't accentuate upper registers too much.
This illustrates what I wanted - I was recently listening to a live performance of a small Baroque ensemble and when the period Oboe was played with gusto, it blatted, squawked, and sounded harsh but yet it didn't make you recoil like a harsh recording can. When the soprano let lose with a fortissimo passage, that was also harsh but it didn't make you recoil like you might when listening to recording playback.
When I installed one of PS Audio's AC12 power cords on the amp, the amp hit its stride and was much better balanced (within the limitations of the recording.) Bass and treble were in balance without exaggeration, and there was far less tendency for previously excessively sibilant recordings to sound too harsh. Harsh musical elements sound harsh but without as much glare as was evident previously.
Admittedly, the differences in power cords are fairly subtle and I can understand how some would consider the costs to be out of proportion to the benefit.
