Teufel streaming devices* offer a power-saving management (Eco mode), i.e. the boxes switch to standby after a definable time when they are not receiving a signal. You can access the setting via the following menu path:
Menu > Settings > Rooms & Devices > Room name with your device > Device.
In the menu you can set the time to standby (min 5 min/max 60 min) or disable standby completely.
*Devices of the 1st generation (Raumfeld) do not support this function.