I have an HK520. I was late night web browsing and came across this user review for the receiver. Can anyone explain the technical significance of the review excerpt? I am always looking for ways to improve the sound. "Placing something small and heavy on top of the case helps the sound become smoother, and replacing the stock preout/main in jumpers with something like the Audioquest Jumpers brings out more smoothness and detail, while eliminating some of the harshness to the sound."