“the influence of the power cable is inversely proportional to the quality and sophistication of the built in power filtering and power supply of any component.”
That quote sounds good, makes sense. But my experience definitely does not confirm it, nor at first blush refute it. This would need to be backed up by lots of observations. I can think of lots of possible contra examples from my experience but most are confounded by some factor. But, better sounding equipment is much more sensitive to small differences… so I have my doubts… I would always test.