Devialet Expert isn't good in showing secondary harmonics?

[ogs]

Can people actually hear these things?

I don't mean 'does it make a difference', I mean more like someone plays you some music through a new amplifier and you, having years of listening experience, say 'thats absolutely lovely, but it's somewhat lacking in second harmonics, which I'm finding a touch lower than the 3rd harmonics - I think if we just had a 10% increase in the 2nd harmonics, things would really fall into place with a lovely balanced coherent sound' type thing…..

I obviously dont know what Im talking about, but Im always fascinated when people can identify such things.  On lots of forum posts I've read recently people were able to hear all sorts - jitter in the order of picoseconds, USB grounds, specific FIR filters etc etc.  I doubt I'd know what any of these things sounded like unless I was guided through it in a lab environment.

It is possible to hear, yes, but not quite the way you describe.   If an amp only produces odd order distortion you'd probably find it "cold" or "sterile" - especially if you then compare it to a similar design with even order distortion dominating. The distortion signature is of course not the only factor. McIntosh uses transformer outputs even on their transistor designs to "balance" the sound... Feedback vs no feedback is one factor - and so on.