Originally Posted by pulsetsar
I am primarily an audiophile and have an extra aftermarket power cable lying around from my audio equipment - a Shunyata Venom 3. The improvement these cables make in audio is incredible and in my mind quite undeniable. I haven't used a cable for my TV or any video source before, but I did upgrade the power outlet to which my whole system connects and this made a noticeable difference in the video quality in terms of black levels and color representation - one that even my wife noticed and that I wasn't expecting (again, I'm mostly an audiophile).
I was hoping to give this a try on the plasma display to see for myself if there were any noticeable difference from an improved cable. If it's not possible, I guess I'll just sell it - the aftermarket value of Shunyata cables is still quite good.
After reading this post I was really considering taking the advice Thumper's mother gave to him: "If you can't say something nice, don't say nothing at all." But I can't let others infer that it's possible to improve black levels, cure floating blacks, and promote new hair growth by replacing your stock power cords without saying something. Therefore I'll add my personal experiences to what Randy and the others have said
I spent over twenty years repairing all sorts of consumer electronics equipment (now retired). The mid to high-end audio brands we were factory authorized to service included Rotel, Carver, Harman Kardon, Denon, and many others. Although we were not factory authorized for McIntosh, my partner was factory trained by them and we repaired a good amount of their equipment based on his reputation (He had run the service shop for the largest McIntosh dealer in the state before I lured him away). In order to become authorized for many of those brands you had to invest in top notch test equipment - we did. Those are my credentials. Here's my opinion
I have NEVER heard of a reputable blind test where aftermarket AC power cables were demonstrated to make any difference to the sound of an amp. This included tests we conducted ourselves where in addition to not hearing any difference, we were also unable to measure any.
With that said I'll add this: I have a dedicated 20 amp home run' for my plasma and audio equipment. The reason for this can be appreciated by anyone who's ever seen the lights in a room dim when they've turned on the vacuum cleaner. I could even understand someone with a large plasma and a powerful audio amp running each on its own 20 amp circuit. If you must spend money, do that, as there's a SLIGHT chance it might actually make some difference. But an aftermarket power cord will do absolutely nothing for your audio amp or your plasma.
I realize I'll never convince the OP of this but that's not my intent. I'm just trying to prevent anyone else who may be considering this from wasting their money.