Power Cables and Wall Sockets

One thing that I am curious about is if upgraded power cables will eliminate the issue of my lights dimming when listening at reasonable high volume.

No. I’m 98% sure it will not. That is due to things taking place in the circuit. You may try a new breaker. But there again, I’m not certain. I was a carpenter/building contractor most of my life.I’ll leave the better explanations of why to the electricians

FWIW I will also correct @carlsbad on the size wire in the wall going to the outlet. It is 12 ga rather than 14. I’ve seen 14 used for light switches but not outlets

@hilde45    has a great idea. Each system is different. Some will benefit from PC’s Others will not

One thing that I am curious about is if upgraded power cables will eliminate the issue of my lights dimming when listening at reasonable high volume.

NO!

Installing a dedicated 20 amp circuit for the audio gear will help with the lights dimming. Probably eliminate it.

Mike

Run dedicated lines.

Or spend a couple of grand on a re-generator like what PS Audio offers.

IME they’re additive.  Add a better PC, you can get better sound.  Add a better outlet, you can get better sound.  Add both and you get even better sound.  I’ve said it over and over, but in this hobby EVERYTHING MATTERS and makes a difference.  And a big +1 for dedicated lines.