Hello,
I know a lot of people do not have a brick and mortar shop that lends out cables. This is the best way to try cables and equipment out at home. Also, I will tell you it can take a few hours or even a day or two for cables including power cables. I am not saying you do not hear a difference right away because you should. I call it loading up the cable or letting it balance out or settle in. Interconnects and speaker cables need time because of the lower voltage and I believe it needs to become consistent otherwise it’s like an empty water hose or line that needs to get the air out. Power cords make a difference the next day because the caps in the components need to do the same. Charge up and level out. The first time I noticed what a difference a power cable makes is when I replaced my stock PC on my surround receiver with a Nordost Blue Heaven. It really made a difference. Plus, some of these receivers have 9-13 amplifiers. That’s a lot of power not to mention all the other things in the same box. I say go with a 14 ga power cord so your not starving that equipment. Try it. Take your nice power card from one of your other sources like a phono stage or CD player and put it on your surround system. The next day after you charge up all of the moss caps you will understand. I hope this helps.