I am normally very cynical about the various "accessories" that are sold in the audiophile journals and websites. Many of the products that you see for sale makes me feel embarrassed for the people who work hard to buy such hokum. However, after my system reached a certain level of performance, I finally did buy some aftermarket power cords. I do not want to show bias, so I will not name names. But after upgrading cords for the power amps, preamp, and source components, I could definitely tell a definite increase in performance. These were entry level and mid-grade cords from the same well-known company -- two $700 cables for the two power conditioners, two $300 cords for my amps, and several $80 cords for my source components. The improvement was a definite yes, but I would caution anyone to first spend their money getting good electronics -- the proverbial sow's ear will always be what it is, irregardless of exotic power cords. And, also, if you like the sound of the first cable, follow through with the other components.
Do power cords make a difference?
I have a fairly sophisticated Home Theater set up with top quality components and cabling. I also have a 5 year old female Rhodesian Ridgeback named Lola. Last week I changed just the power cords to my processor and DVD player. Now every time a dog barks or an animal makes its appropriate sound, Lola jumps off of the couch (it is no easy feat to get her off of the couch) and tries to attack the dog or animal making the sound. This did NOT happen before. Motto of the story, yes power cords make a difference that even my dog can tell!!!