I suspect that I am one of the few if not the only person in this discussion that has actually designed and manufactured electrical power generators used with sophisticated electronics. I have been asked by several people to write a white paper on the subject of power transmission as related to HIFI, because the misinformation and counterfeit issues in regard to power cords is enormous. If you polled the engineers here, I suspect you would get a different opinion from each one.
Good power cords can make a difference. However, there is another question that needs to be considered. Are you capable of hearing the difference? The only way you can answer this question is with a hearing test and most people will not bother with finding out the truth about there hearing.
The next question is will a better power cord make a difference with your equipment? Not every piece of equipment will benefit from a power cord upgrade.
Many people ask me questions regarding the design of power cords and then I ask if they are engineers or have a really strong electronics background. Usually the answer they don't have the background to understand. So if you don't know what power is, how do I explain power cord and connector design? I usually just tell people I have a can of "pink fairy dust".
Here are some tips:
If you buy used pcs, they may be counterfeit.
Use products from a reputable manufacturer; materials, high purity copper is a start with quality connectors.
Limited bandwidth power cords will help keep the total system noise level down.
Pcs with high surge current capability will improve the power supply surge capability resulting in better system performance.
If you are on the US North East power grid consider a power conditioner.
If you are on the US North East power grid change your receptacles regularly. Consult an electrician, have one changed, then take a hammer to it and check the condition of the contact surfaces on the receptacle. You may find a surprise.
