If you're going to go for aftermarket power cords, at least consider this

And, this

Can We Hear Differences Between AC Power Cords? - An ABX Blind Test. December, 2004


The Results

The complete Excel spreadsheet with all test results and participant comments can be accessed herein. After the test, Manny spent quite some time analyzing the results and responses to a post-session questionnaire he composed. I owe much of the following analysis to him.

The total number of correct answers was 73 out of 149, which amounts to 49% accuracy. That is no more accurate than flipping a coin, and therefore, no statistically significant detection of power cable differences.

In the spirit of fairness, this was also stated.

Conclusions

To many in the engineering community, blind ABX is an accepted experimental design. Using the blind ABX protocol, we failed to hear any differences between an assortment of generic power cords and Nordost Valhalla. Therefore, we cannot conclude that different power cords produce a difference using the blind ABX protocol. However, we also cannot conclude that there are no differences. We simply failed to prove that differences can be detected to a statistically significant degree using a blind ABX protocol.

John Johnson, who comes from a scientific background, suggests that if there are differences between cords, they appear to be so subtle that a blind ABX test cannot discern them with small numbers of participants. Failure to discern them could be due in part to the time it took for cable changes, and the possibility that accurate auditory memory is shorter than that. It may be necessary to switch between cords in a much shorter time.

Unfortunately, as John notes, we don't know of a way of accomplishing fast power cable changes, since, unlike interconnects which can be simply switched between A and B with the equipment all still powered on and playing music, changing AC power cords requires turning the equipment off, switching the cords, and then powering them back on.



Jack

"People generally quarrel because they cannot argue." - G. K. Chesterton