To All Cable Deniers, 1 Very Simple Question.

I don’t have much to add to the discussion on if or why, but I thought it might be helpful to point out that the last (or first) six feet connecting your equipment to your wall is braided cable (by code) for flexibility while the wire in your wall is solid core. The braided cable has different properties regarding inductance, capacitance and impedance (though that difference must be very small indeed) and all wires act as an antenna of sorts, both broadcasting and receiving.

Does this make an audible difference? While I have found that they do, the affect (to my ears in my system) was not nearly as substantial as other cables. And I didn’t find any difference in modestly priced cables to stock. Worth the spend? To some yes. To many, I would say no. 

While the power cord is part of an overall electrical circuit, there is a basis for the "first six feet" perspective.  This is mostly because of the greater potential for noise in the environment from the wall to the audio component, than inside of the wall.  

The primary culprits seem to be:

• induced noise from electromagnetic fields interfering with nearby (signal-carrying) audio interconnects, 
• high-frequency noise (RFI) from Wi-Fi, cell phones, rheostats, and appliances that is more prevalent in an open room than inside the wall, and
• feedback in the power line resulting from other audio components, and particularly those with switching power supplies.

Therefore, whether considered the first or last six feet, the component power cord is more likely to pick-up and/or transmit noise to an audio component, or system, than the in-wall wiring preceding it.  However, assuming the power cord has adequate wire gauge for the current being transmitted, and is properly grounded, the ability to resist noise seems to be mostly related to having adequate shielding, and possibly noise reducing geometry, than about fancy metallurgy and other attributes that drive stratospheric pricing.  In addition, the quality of the component power supply also plays a big role in overall system performance by adequately filtering and regulating the incoming AC into clean, stable DC voltage as demanded by the component.

@mgrif104 I think you meant stranded, not braided.

@invalid 

I did mean stranded. Thanks for the clarification. And I had even had my coffee by that time. 

mitch2, there is a very simple method available to cancel, or to reduce, EMI field around power cable, which is a twisting (plenty twisted cables available) hot&cold wires once/twice per inch! if AC powered device is not designed properly to reject high freq. RFI, not enough chokes/caps/filters, then everyone can use ferrite core clamp on top of cable, the best is close to IEC plug, which rejects RF noise entering amp/pre/etc by 40..60dB +! plenty of different options available at low price: https://www.digikey.com/en/product-highlight/f/fair-rite-products/snap-it-snap-clamp-on-ferrite-cores adding simple ferrite clamp can convert original power cable to awesome sounding, magic one!