Re: Power Cords
Marketing...no other way to explain it.
12 AWG.? THAT is bigger gauge than what is in the wall of a residence.
Power and Speaker cable are the exact same theory.....they are a high power conductor. Nothing that is nearby a guitar amp is going to influence them, unlike a Very Low Voltage instrument cable.
My wife has a nice pair of Klipsch Chorus Speakers. We just moved them into a much bigger room, so i need longer cables.
I went to Home Depot and bought one of these.
http://www.homedepot.com/p/Husky-50-ft-16-2-Outdoor-Extension-Cord-53050HDX/206460233
I cut That in half, installed banana plugs, and i now have excellent speaker cables that rival any cables, anywhere, at any price.
If the wires can handle the power, it makes a perfectly, excellent speaker cable. If the connectors are good (and GOOD Connectors are NOT Expensive) and properly installed.....you are good to go.
My speaker cables were about 40 bux for 50 feet. They sound just as good as Any 25 foot speaker cable that somebody might have paid 150-350-750-1250 dollars, etc etc etc.
PLUS.....mine are an Awesome Neon Green.

AC cords are the same thing. They can either handle the wattage going into your amp, or they cannot. If your amp draws 3.5 Amperes, installing a power cord that can handle 400 Amps is not going to improve anything.
good luck