when looking to buy a power cord for say a amp, how do you know which one to get ?
does a company make a power cord to sound a certain way ?
Buy nothing you can't hear value in yourself.
The claim is that power cords can make all sorts of audible effects come out, almost none of which I have experienced. My current thinking on power cables and conditioners is here:
https://inatinear.blogspot.com/2019/04/power-management-for-frugal-audiophiles.html
I think, if you can hear audio cables, their effect is best when power is worst, so my advice is in general to get a good conditioner, and modest power cables.