power cable

Be open to the possibility that the new cable may not perform better than your current cables on either component; just because it seemed like "a deal" doesn't mean that it was one for your system.

Power chords are typically used with amplifiers.

Chords are typically used with music.......

Yes builder3. Chords are for music. Cords are for electrical purposes.

But then the power chord comes in.

"A power chord play is a colloquial name for a chord in guitar music, especially electric guitar, that consists of the root note and the fifth, as well as possibly octaves of those notes. Power chords are commonly played on amplified guitars, especially on electric guitar with intentionally added distortion or overdrive effects. Power chords are a key element of many styles of rock, especially heavy metal and punk rock. Wikipedia"

Come on guys, you know exactly what he meant. 
 

Power cord upgrades to amps tend to produce the greatest effect, and can be huge. For instance, my Audio Research Ref 160s comes with a very heavy copper 20 amp power cord. The first and all subsequent power cords I tried were much better, but many pushed the sound tonally, ever so slightly. It took me a year of occasionally trying something different until I found the perfect match… and it was way better. It was an Audioquest Hurricane. Absolutely no tipping of tonal balance, much quieter, more dynamic.