Actually it is all about money.

I've gone through formal bias controlled comparisons.  My results are that 256K and 320K MP3 sound the same to me as the native CD.  With some recordings I can distinguish between the CD and a 192K MP3.  At 128K I can distinguish them every time.

  It is expectation bias.  Silver is rarer and more expensive than copper so you expect it to work "better."  A bias controlled comparison will clear that up for you.  Silver does conduct electricity somewhat better than copper so to have the same measured performance the copper wire would need...

"Opinions on using "No-Ox" to protect connectors?"   One of many ways for the high end audio industry to get some of your money for no useful purpose.

There is no soundstage in headphone listening.  Binaural sound reproduction places everything in the middle of your head.

  In my case you are comparing opinion to test results.  Not exactly the same thing.   Good bye to you too.

Curious that headphone listeners would talk about soundstage which is adjusted by the distance speakers are apart from each other.  Headphones make the soundstage a point inside the head.  I can't imagine giving the concept a second thought with headphones.

The reason tube amps have the sound they do is audible distortion.  High fidelity solid state amps have distortion figures that are well below the level of audibility.  You can certainly create a gushy warm sound with equalization but it still won't have the audible distortion of the tube amp. ...

  It isn't a delusion.  It is just a matter of misunderstanding.  Better specifications can certainly indicate better performance.  But when the specifications are below the level of audibility, they lose that capability.  Every thing in audio is measurable.  Not everything is audible.  ...

  You don't need math.  Common sense should get you there.  If you have a 16/44.1 red book music file and you want to  upsample it, where do you get the data to add to the data that is there?  If you create it out of thin air how does the algorithm decide where zeros should go and where ones...

  Two possibilities.  The most obvious is that the comparisons were not made with level matched, bias controlled comparisons making the results invalid and meaningless.  The less obvious possibility would be a severe impedance mismatch between the amp and the headphone.

I view all of audio as "responsible."

Hello.  What is wrong with the dac you have?

  The reason is quite simple. Spending money on "better" cables creates an expectation that biases hearing.  Wire is wire unless the manufacturer attaches some sort of filter to the cable.  The sonic signatures are in the hearing bias not the cables.  Here is a very brief explanation.