Generally wise/unwise to mix metals in AC plugs?

Just got a pc with gold plated plugs on both ends and the effect is to soften and merge contours -- "voices" sound like they're coming through a soft cotton scrim. Used on my dac. It's great for the many lo-fi historical opera recordings I listen to, but not for most everything else. Gold seems to take an edge off and to accentuate note decay. I like that. But double- gold is for normal purposes too much of a good thing.

So... maybe replace the male end with copper? I wonder what gold and silver would do?

Every wire, every connector, every circuit board, every capacitor lead, resistor lead, solder.. thousands of changes in metal formulation, drawn, cast, soldered, stamped...Copper, pure copper, various grades of cheap copper, Carbon, silicon, rare metals embedded in matrices.. Amazing anything reasonably like music comes out the end with the signal going through around under between all this stuff.