I have a Yamaha RX-A3080 which has a 2-prong AC outlet on it. I have an audiophile 3-prong power cord from an old setup. Can use that power cord with the 3080?
There's no real reason to do this. Nothing else will have changed, neither will the signal getting to the power supply which, BTW, filters out everything on the signal from the grid. Sell the power cord and get what you can. If you believe the hype about power cords, you're ignoring the whole grid, the wiring and all of the electrical parts between the pole and your equipment. It all matters, or none of it matters- changing one or two pieces can't make a demonstrable difference unless the part(s) replaced can be proved faulty or simply making a connection causes some kind of improvement in the contact between the wires and part(s).