Ha, ha, Amir strikes again. The most relevant quote -
What is going on? Simple: you frame of mind makes a huge difference in what you perceive. When performing comparisons, your brain gets into instrumentation mode and analyzes music differently than when you lean back and just enjoy music. In doing so, it hears more detail, air, etc. It does so even when nothing is changed in the waveform. In other words, the Ethernet switch is not changing sound. It is you that is changing.
-