jinjuku, as you said, " The upstream amp, cabling, speakers, room interaction, are all moot because they aren't in the loop." Do you have any idea how many times I have heard that both from people who have or have not done testing as you have?
It's the same logic that is employed by those who disdain power cords by saying, "How can it make any difference? There are miles of lines between the power company... the wiring in the wall, etc." SIGH. Wonderful logic, lousy system building.
You say, "If the Ethernet cable is altering the output of the DAC then it should be captured in the tracks I provided." Perhaps. That will happen if the system is good enough. If it's poor then likely the difference will not be noticeable. Seriously, a couple hundred dollar system is what you are putting up for evidence? How about you get some serious gear and do the test? Audiophilia is not the reduction of quality to the lowest common denominator. You WILL get mediocre sound that way.
You didn't answer my question regarding comparison to a dedicated server. Have you done comparison between your cheap computer digital source and a dedicated audiophile grade server? I suspect the analogue output stage of the dedicated server will make your computer source sound horrid and so compromised that it seems half the information was missing in playback. That is why I think you have support for your perspective, but it's based on wretched gear that is not able to produce a good result.
I suspect it would take about ten seconds for you to be humbled in your confidence about your digital source when compared to a fine server such as the Salk StreamPlayer Gen II.
Sorry, but I'm not impressed by your couple hundred dollar experiment. If you want to get serious, get some serious gear and do some cable changes as I have done. It's not difficult, and you will be humbled. And, you will have FAR better sounding music.
