Audio Science Review of Expert 200.

[ogs]

Can anyone explain this?

I'm not sure I know, but I suggest the following: The design does not have enough cooling for full power measurements (which uses sustained test signals) so the protection is configured to trig at a very low (safe) level. Music is dynamic in character and thus will not trig protection.
Give a Devialet amp massive (enough) cooling and re-program the protection logic and the amp would also measure at full rate.