Michael: Until you can get rid of / suppress the noise and interference on the line, you'll never have a "neutral" power cord. That's because the impedance and design of the cord itself will introduce varying levels of filtering / wave-shaping distortions to the broad-band "polluted" signal entering the device.
If you get rid of the noise / interference before it enters the power cord, the characteristics of the power cord become FAR less critical. That's because all the power cord has left to do is to maintain the purity and amplitude of the signal that was fed into it and keep its' own "antenna action" to a minimum. After all, we are talking about a 60 Hz sine wave here. You don't need to worry about too much here as a sine wave is FAR more limited in bandwidth and duty cycle as compared to that of a square wave, etc... This reduces the need for fast transient response and / or wide bandwidth, so skin effect isn't of much concern either.
It's too bad that people are gullible enough / lack the proper education in certain areas to pay good money for a few dB's of non-linear attenuation / elevation with random results and predictability. They could be achieving results that are both far more consistent, linear and measurable for equal or less money. Then again, nobody ever said that all audiophiles were smart shoppers or that all cable manufacturers were honest or ethical.
Carry on, my wayward son.... Sean
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