I just purchased some entry level power cords from PS Audio for my sources and pre. Upgraded the receptacle and then sourced good parts and assemble my own amplifier Power Cord. I didn’t even try to figure out if it made a difference. If you have not assemble you own PC I suggest giving it a whirl. Its fun and an easy part of the hobby. If I get motivated I want to make one for my DAC.
If you go over to the Cables section those guys will stupefy you with suggestions on what to us for construction.