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.