Hello John,
With all due respect, in my experience, the ability of enthusiastic amateurs to set up and conduct a really scientifically controlled listening comparison (unless they are supervised by a person long experienced in double-blind comparisons) is dubious at best. (Yes, I once belonged to various audiophile groups and I'd include myself in the category of an enthusiastic amateur until, as an editor of various audio and AV magazines, I began professionally reviewing, testing and working with Dr. Floyd Toole at the National Research Council's Acoustics program.)
The vast majority of enthusiasts have so much of their personal ego (and money) invested in their cherished audiophile beliefs and in their equipment that they are unable to separate those and simply participate in an unbiased comparison. In past experiences, I've found enthusiasts claim that listening to one CD player, stopping it, putting the disc into the other player, then listening to it again, constitutes a valid comparison!
Such comparisons are worthless; I suspect that you and your audio buffs lapsed in some area, whether it was prior knowledge of the equipment being compared, the brands or the prices, slight differences in level between the two sources, and non-blind switching. As Dr. Toole recently remarked after the publication of a recent white paper "Blind vs. Sighted Listening Comparisons," if you can see it, you can't hear it!
You must understand that until I was able to participate in really controlled comparisons, I was a "believer" in high-end audiophilia, and that such differences that you allege to be audible--"DACs used in respective players"--I sincerely believed. That all changed more than 25 years ago.
Incidentally, my comments do not apply to other components you mentioned and don't extrapolate my views to those. Good heavens, phono cartridges, for example, are relatively crude tranducers with all sorts of nasty non-linearities and distortions that are readily audible and easily measured.
If you'd like to drop by Axiom's listening room at the plant on some future occasion, I'd be delighted to set up a properly controlled double-blind comparison of a modest but well-designed CD player with some high-end player that you think has "superior-sounding DACs".
Such a comparison would assume that the analog output sections are well-designed and linear. If an analog output section had serious design errors or frequency response aberrations, of course there would be an audible difference--and it would be measureable. However, that's rare these days.
Regards,
