20 amp cables for PS Audio P20?

Hi I’ve recently acquired a PS Audio p20 power plant. Someone mentioned that a 20A power cable is better sounding.  I don’t understand. Does it make any difference really?  My circuit is 15A. Thanks!
Power cables do make a difference on the Power Regenerators; they’re essentially a power amp and have a power supply… they make a difference and I’d recommend using a large shielded power cable with dedicated circuits to get the best out of your P20.
I have had several components IEC converted to 20amp because many cable IECs do not fit tight. Other than that a heavy gauge cord is essential to handle the current

Example, I have  Kaloric Air Fry oven; the connected PC gets really warm when using it at 400*s+ for > 10 minutes 
I’m not sure if a 20A cable will sound different just because it is a 20A cable, but the P20 will provide more power and probably sound a little better when fed with a 20A cable from a 20A circuit.  If you only have a 15A circuit no point in the 20A cable.  Having said that, I would strongly recommend running a 20A dedicated line with 10 Gage wire for the P20.  That will give the best performance out of the P20.
If the PS20 has a 20 amp IEC than use a 20 amp cord, if not use the 15 amp cord.  Don’t make it harder than it needs to be. I would use at minimum a 10 gauge cord.