Does Power Cord Require Burn-In To Sound Good?

Depends on the cord...MIT Oracle or REV AC 2 from Joe Abrams may take a hundred hours or so due to parallel networks but mostly for wire and insulation to loosen up.  Everything sounds better after it’s been used awhile!

It just seems so "Odd".
Odd that, "certain people", wish those of us whom have found that using a different power cable may change, "For the better" the music we hold so dear.
As if they are going to somehow, "Save us from ourselves". 
And they believe- They are doing a good deed. To, "Save us",- Some of our money, some of our time.
 And apparently, 
They are VERY worried about us.
Worried about us, "Looking Silly". 
But To whom?

They remind me of "teenagers". Which at certain stages are always embarrassed by their parents. Embarrassed by absolutely everything a parent "does", "say's", or even, "thinks".
Because in a nutshell? We do not, "Look Cool".
     "To them".
     But I "Feel cool"....

  So in order to show us all the error's we are making. So that we may learn to mend our way's? And see things, "Their way"?
They are armed with more tools than we could possibly ever even think to counter.
  And OH!, their "Mastery", of these tools!
And the tools are?
"Well typically"......
Basic, "Math, Physics and Ohm's Law". 
And, "Oop's" I forgot! About, (Common sense). There is usually one to throw that in as well.
So, a voltage drop calculation and maybe a quote from the, "NEC" and then a smart remark, "As pop used to say".
And as teenager's always do, they then share those secret, "knowing looks",
Because they are just so sure that "We", have never really been around the block as they have been.
OR, we have just gotten too old and forgotten, "Everything", "POOF"~!
Sound familiar?
 
My rig sounds amazing, "Both".
 And, I look cool too.



(I hope this works).

I’m a believer in PC burn-in because I can hear the changes. I’m not going to debate in yet another cable break-in thread, I'm only giving an opinion.
I use two different brands of power cables in my system, one inexpensive, the other rather pricey.
It’s interesting that both manufacturers believe in break-in of their cables. One is a dealer/manufacturer for Furutech and he puts his PC’s on a cable cooker for hours. The other designer recommends a break-in period. They site specs and measurements, but still the cable needs to be run-in. Maybe it’s because they’ve designed and built the cables with certain materials for conductors, dielectric, shielding, etc. that provides them this knowledge of cable performance.

I do believe that if your system isn’t revealing enough, sonic changes in cables may not be noticed. And some low current components may not present a perceived change in aftermarket and stock cables.

I installed a Nordost QX4 a few months ago and it has made a significant and positive difference in my system. More soundstage and more depth. 
Power and its handling is the heart of the system. Power cords and a conditioner. Try Nordost. 

I assume you have a power conditioner of some type.  If not I would suggest a Shunyata with their cords which have been broken before shipping.   Use NR cables for equipment and XC cable to connect from the wall outlet to the power conditioner.   Also, replace your wall outlet if you have not done so with a hospital-grade outlet.   The outlet will provide better wall connectivity.