Thanks! A little disjointed with the translation, but lots of information. Is the consensus that those tests were performed properly? Those are some pretty wild results if so.
People with nothing better to offer will try to quibble with them, as they will with any tests they don't like the results of. But the results (both negative and, in a few cases, positive) are exactly what you'd expect if you know the science behind this stuff.
As promised, some published tests on the subject:
—Masters, Ian G. and Clark, D. L., "Do All CD Players Sound the Same?", Stereo Review, pp.50-57 (January 1986)
—Pohlmann, Ken C., "6 Top CD Players: Can You Hear the Difference?", Stereo Review, pp.76-84 (December 1988)
—Pohlmann, Ken C., "The New CD Players, Can You Hear the Difference?", Stereo Review, pp.60-67 (October 1990)
—CD Player Comparison, The Sensible Sound, # 75, Jun/Jul 1999.
—CD Player Comparison, The Sensible Sound, # 74, Apr/May 1999.
If memory serves, the first article did find a difference between a first-generation CD player and newer models. Beyond that, all were indistinguishable. Again, not surprising if you know how DACs—and ears!—work.
right now I'm just using the computer's 3.5mm audio out to my integrated. I've been thinking it would probably be good to switch to the PC's optical output and insert an external DAC into the chain.
Couldn't hurt, might help.