Kef reference 1

[gitaarwerk]

Ah, I get it. The sound has less "color" and you use the term "flat". There is less harmonic flavor to the sound than you are used to. A bit like plugging an electric guitar directly into a mixing console instead of using a proper tubed guitar amp with a suitable microphone in front of it.
Yes, the Devialet amps are very clean and neutral. I know some people coming from classic tube amps feel the sound of Devialet amps to be lean to begin with, but find it hard to go back to tubes after getting used to their Devialets.

Yes, :-) Sorry if confused you. I sometimes am confused with the terminology. Exactly what you described is what I mean.

I think you should see flat as a good thing. Because SAM does introduce more stable sound stage. That is still really really good. Flat in my ears means not too excited/harmonics/distortion. It's just not something I was used to. Before this, I had a bi-amped Exposure 2010S2 set, which wasn't very powerful. 

Its not lifeless, but maybe its less distortion what makes the difference sound more flat than it used to be. The exposures, looking at the noise/thd charts, tell me they are really not so great distortion. While i.e. Devialet or other brands as Accuphase E207 are. That, could exactly be the issue. If the distortion is a nice harmonic, it does add to the sound. It excites, but is not a fair reproduction. So I would say if that's my reference point, the devialet sounds "more boring" than before. Which is not fair, but it's for me the truth. And as I mentioned earlier, that's just getting used to it. In the end, I would assume devialet users, as me, are in search of great reproduction.

Ah, you are talking about the sonic signature of the amp itself. So when you say "flat", you mean to say "neutral" meaning the amp doesn't impart any enhancement of the frequency range (ie. detailed which might mean enhancing the treble, warm which might mean enhancing the midrange, etc). Correct?

Indeed :-)