Measuring objectively real differences in files with identical checksums

[Archimago]

5 hours ago, jabbr said:

I tried to listen for differences in sound from two but identical files, but couldn’t hear any. Then I realized that my file system (ZFS) automagically maps identical files to the same location (actually it does block level de duplication) , so I can’t even test this. 

 

Well then, that "version" stored on your file system could be the absolute best or absolute worst copy of the music...

 

Which is it based on the theory of how this is supposed to work? Or is it all just "different" and equal with no relative judgment possible!?

[Archimago]

On 2/26/2020 at 4:59 PM, fas42 said:

The process of retrieving digital data which contains the recording can be 'different', every time; even if it's the same data, each time! For a myriad of subtle, but non-trivial reasons. For an analogue analogy - you play the same track of a record, one following the other - the cartridge has warmed up a bit more, the plasticity of the record has slightly altered, the dust in the grooves has been pushed aside; and on it goes.

 

But digital is different!!!, you say ... umm, good theory, but the reality I've found is that there are enough leaks through the supposed barrier to the analogue areas, to cause an audible variation.

Easy to say... But unless you have some suggestions as to how one verifies this belief/claim/idea/suspicion/article of faith, there is no path forward in these discussions.

 

I've tried. I hear no difference. I measure no difference (eg. between lossless file formats). Jitter these days is very well controlled without the use of any doohickeys and IMO inaudible. Noise is absent (significantly below -100dBFS) from inexpensive modern DACs and CD players. If anything, it's the amplifier and speakers creating more distortion and limiting noise floor; not to mention the ambient noise in one's listening room.

 

Even if retrieval & reproduction is a little different each time, the variance is way below audibility with repeated measurements. Essentially bits are bits given the accuracy of modern digital systems.

 

Where is your evidence/rationale to show otherwise beyond an idiosyncratic belief system unsupported even by controlled listening, so as to have a reasonable/meaningful discussion going forward??? This is of course not just a challenge to you Frank, but basically a broad question to all those who insist that there is still some significant issue that can be affected by cables/regenerators/filters/etc.