it has a profound effect on the sound by the simple virtue of allowing electrical current to flow into the equipment. Then the unit can be "switched on" and start to reproduce music .It is a KEY piece of the hifi food chain.
That said we humans still have no idea what 60% or more of what the universe is made of (dark matter, dark energy, black velvet ??) so everything effects everything. I have a nice $200 Steve Cullen AC cable that absolutely sucked the life out of my amp. It was replaced with a 20 dollar hospital grade green dot cable that dropped the noise floor to the sub-basement and added some luster to the amp, so go figure. $50 plus shipping will get you that Cullen cable if you are interested.
That said we humans still have no idea what 60% or more of what the universe is made of (dark matter, dark energy, black velvet ??) so everything effects everything. I have a nice $200 Steve Cullen AC cable that absolutely sucked the life out of my amp. It was replaced with a 20 dollar hospital grade green dot cable that dropped the noise floor to the sub-basement and added some luster to the amp, so go figure. $50 plus shipping will get you that Cullen cable if you are interested.