Do I need upgraded power cables?

Ignore trolls.

"Ignore trolls." By trolls do you mean ignorant people living in a delusional reality of imagination with ZERO proof to back up their claims or people with actual knowledge and FACTS to prove their claims?

I have been listening to audiophile grade equipment for 25 years. The first items I bought came with an upgraded, aftermarket power cord (for amplifiers).  Since then I have used mostly standard power cords with my other equipment.  Over the years I did try one or two slightly upgraded power cords ($50-300) in my pre-amplifier and other components, but didn’t hear any difference.  Last year, I bought standard power cords for my amplifiers, and didn’t realize it initially, but it did slightly affect the sound quality in a negative way.  Just this past month I demo’d markedly expensive power cords ($1,500+) in my pre-amplifier, and heard a rather significant difference:  it affected the timbre of the instruments, and slightly enhanced the clarity.  This was a difference, but was it better?  Some parts were better, but overall it was just different, kind of like trying different interconnects.  Prior to this experience, I did not think a power cord could make much of a difference.  While I was experiencing this, I also learned a bit of electrical engineering, about how AC waves can have reflections at interfaces, due to different impedances of the conducting materials, which can create an interference pattern in the otherwise 60Hz wave.  Maybe that is part of what’s happening, maybe it’s something else.

Unless you had a broken cable, there is no difference you are going to hear or measure. This has been tested MANY times. There is a reason there is not a single blind test ever where anyone claiming to hear such differences was able to prove it.
Placebo and bias are very strong things and nobody is immune to it.
Heck, many times I thought for sure I would be able to tell between two dacs or cables just to have my wife come to the room and blind test me and I failed miserable...just like EVERY other person that has tried testing power cables,.
Dont feel bad..the mind is a powerful thing and can easily fool us.

drbond, what is "standard power cords for my amplifiers”? 

power interconnect issues could be related to bad contacts, oxidation, etc., including IEC and wall connections; periodic maintenance helps.