Re: Take it my simple view is flawed then?
Yes - too simplistic
As I explained above the problem with MP3 is that it adds crap that is not harmonically related to the source music. Added interference, in other words. Noise that was not represented at all in the original data stream.
Which is why compressed MP3s sound shite even on cheap reproduction systems. Only digital compression can do this. (OK, perhaps an off-centre loudspeaker scraping on its magnet can also have this effect ... but that's at such a high level, you immediately diagnose the problem and scrap the speaker).
Slight non-linearity in an amp can create only harmonic distortion. not new noises. The weighting of frequencies that are not harmonically related to the input remains zero.