Kef reference 1

[ogs]

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.