All GamuT amplifiers (except maybe the S300), as Ngjockey mentioned, are input- sensitive/gain adjustable not just by the dealer but the user can do it as well.
I have changed the settings on GamuT a D200 stereo and M200 monos amps. Each model required a different setting with the same pre-amp. This feature is super useful. It would be cool if more amps had this capability.