Dear @johnss : No, frequency response is not the only answer but part of a whole answer as could be: noise levels, any kind ditortion levels, etc, etc.
The main subject is what is truer to the recording/what microphones pick-up: analog or digital? The overall and very wide explanation for some other time.
""" for another easy test, go to any audiophile meeting where they are playing hi rez digital files. people will be chatting away.
step in with a high speed analog machine and play a tape. All side conversation stops instantly. """
I know you are a wise/intelligent gentleman and then you will understand my opinion about:
that’s or could be true for a very " easy " reason: if for 40+ years your ears/brain/body is accustommed to listen only analog in home system is obvious that listen it to a wide radical different MUSIC presentation as digital the brain does not tooks very seriously as is something " new " and something that must be assimilated/understan to its advantages can have a meaning for the brain a true superiority meaning.
The subject is: how many time takes the brain to assimilates the top today digital MUSIC home system presentation in favor of it in favor to analog?
As we are more and more exposed to that today digital MUSIC preesentation as more we like it. Yes, is different to analog presentation because is a way different technology that between other things has a clear advantage: almost each day is improving it as technology when analog has several years that just stoppedto achieve true improvements and that’s why so many audiophiles are buying vintage analog audio items.
The overall digital/analog subject is not very complex to speak about but that we analog lovers likes to make it " controversial ". Is human been nature.
In the other side and returning to R2R issue: did you test a Sheffield D2D recording against the same Sheffield recording that was made it through a first first rate tape machine?.
That's a true easy way to any one can detect the damage made it by that top R2R machine. Btw, digital is superior medium, yes different.
Regards and enjoy the MUSIC NOT DISTORTIONS,
R.