Bit perfect software changing sound. How?

[vortecjr]

1 hour ago, March Audio said:

Ethernet solves the specific problems I noted earlier as it provides galvanic isolation.  Its built into all ethernet adaptors.

Not according to measurements from Archimago posted here: Archimago's Musings: MEASUREMENTS: On the value for ethernet "galvanic isolation"...

 

According to the article, "Over the years, I have already demonstrated that ethernet works well as a means of digital audio data transmission. I have never found any differences in cables used, and sound quality is fine whether used locally or transmitted globally. But what about this issue of the possibility of electrical interference and the potential for improvement with galvanic isolation? Well, I think I can show what in practice successful galvanic isolation would look like at my home...

 

Remember this noise plot I showed a few weeks back when measuring the Raspberry Pi 3 + HiFiBerry DAC+ Pro run off a lithium battery?

Interesting don't you think that there's a 60Hz hum (red circle) even in the situation with the lithium ion battery (green) compared to when plugged into an AC adaptor (white)? Hmmmm, where does that come from given that the whole playback and measurement chain is run off batteries - the lithium battery in my laptop feeding the ADC, and the Duracell battery powering the Pi 3 and HiFiBerry DAC+ Pro board?

 

The answer was obvious. It was a very low amount of noise seeping in from the ethernet connection."

 

BTW the above is not a one off as John S. in this forum showed similar AC noise leakage over copper ethernet. He went a little further and showed when / why it happens and offered a remedy. You can read more about his measurements and solution to the issue here:

https://audiophilestyle.com/forums/topic/37034-smps-and-grounding/?tab=comments#comment-721414

 

Of course none of this is a concern with fiber optic ethernet that provide true 100% galvanic isolation.

[vortecjr]

From the batteries Archimago used and FYI John didn't use a DAC in his measurements;)  Disprove the two measurements and present your data or no one will accept your replay.