Prior to working in IT, I used to repair Video Cameras, Radios, Televisions and Video Cassette recorders. I also have extensive experience repairing Hi-Fi amplifiers (proper Hi-Fi not the "all in one" junk), and have also been known to repair CD players too.
I have also dabbled in electronics design, mostly Hi-Fi amplifiers and Pre-Amplifiers (I'm a Hi-Fi enthusiast, although I wouldn't describe myself as a typical 'audiophile').
I have yet to be convinced of some of the "black art" techniques used to attain that "elusive sound" that so many audiophiles talk about.
Competent design and system integration is all that's required to get a good, detailed sound in my humble opinion.