I've read that paper before and now I've read it again.

Although the paper does contain some useful tips, it also contains so much conjecture and downright misinformation, that I find it painful to read.

I find it particularly painful to see the author claiming that ripped WAV files on the computer, which are digitially identical, can sound different depending on which program was used to extract it from the Audio CD.

The placebo effect is very powerful for people who believe that some change they make to their Hi-Fi setup improves sound. Most of the time the perceived difference disappears when doing scientific double-blind testing on the same equipment.

I've performed enough listening tests myself to know how people can fool themselves in non-blind or even single-blind listening tests. People hear what they expect to hear or want to hear, and once they have a made a decision they will come up with all sorts of arguments to justify what they think they heard.