Taken from Elliott’s sound products page:
"I refuse to prove that I exist," says God, "for proof denies faith, and without faith, I am nothing."
From ’The Hitchhikers Guide to the Galaxy’, Douglas Adams
The above could just as easily be re-phrased - for example ...
"I refuse to prove that my cables/risers/fuses will make your system sound better", says the snake oil vendor, "for proof denies faith, and without faith, you will hear nothing."