Power cable education needed

" the quality of the power cord matters just as much as the quality of the amp"

@Ronboco, you may be a newbie.  Please don't listen to Miller.  The above is possibly the biggest load of hogwash he has ever written.  Being over-generous to him, this is at best a maaaassssssiiiivveee overstatement.

@jerkface,

I appreciate your input and I’ve learned that treating a room is critical to good sound. I do have panels from vicoustics and gik on the walls. Have a look and tell me what you think. My room question was referring to the fact it’s not a great room really for a high end system being 2 story and open to other areas. I was wondering if there comes a point when continued upgrades would become fruitless because of the room. 

I'll second to that. I have a box of power cords acquired over the years. I am familiar with their sound signatures in my setup and in my listening room.

When my friends were in my house one time we were arguing the same things about the effect of PC. So I picked one different PC and ask my friend to either switch it with a component or don't. I stayed at another room. I was able to pick up correctly 100% after a few changes, so was my wife. 

But most of them still could not tell the difference. I learnt that blind test is tricky. Because I am familiar with the sound of my system in my room, and I am very familiar with the sound of my power cords, I could tell the sound change easily and they could not. 

if I am in a different environment and use cables that I am not familiar with, I probably will not be able to tell the difference either.