The weakest spot of power cables is not the wire itself, and not the power plug or the inlet plug, but the termination of wire to either of them and the mating resistance. It is seldom done right and at full load these connections heat up quite a bit. Here is a thermal image: https://www.onfilter.com/cable-temperature The cables are industrial-grade with C15 and C19 inlet plugs. The loads are ~15A and ~20A on each correspondingly. You can see that wire itself isn't a problem for heat dissipation, but the connections are - it is hard to discern between the temperature on wire connection to the metal parts of C15 and C19, or the mating parts of the connectors. Whether this affects the sound is in the ear of beholder, but the lower the heat dissipation, reversely counted, the lower the resistance, and theoretically lower minute AC voltage variations based on load current. If you are curious to test it yourself, we use FLIR One Pro for these images.
If Power Cords Don't Matter...
First of all, I don’t own any high-end power cords, mostly because I can’t fit them behind my rack. Second, I am not trying to stir up controversy, as you will see from my question. I understand that the people who believe power cords make no difference argue that once the power gets into the component, the AC is converted to DC and the power supply of the component takes over completely. I think I have that right for the most part. So it that’s true, and it probably is from a traditional EE standpoint, why is it that I have not heard anyone say that power conditioners make no difference? I am not aware of anyone with a decent system ever saying that a Niagara or Triton or Audience teflon conditioner didn’t affect their sound, for good or for bad. So if the EE theory is true, wouldn’t power conditioners make no difference either? I have an Audience AR6T for almost 10 years and I think it made a big difference. BTW - I am not talking about Power Plants, which deal with voltage stabilization, which is a different topic. Obviously, if your AC voltage is way off, it's going to cause problems.