I think this can certainly be done via the headphone connection on the back (analogue signals), e.g. via a 3.5 mm to cinch cable. But the radio must then be turned on and off separately, and you also have a volume control on the radio in addition to the hi-fi system (if the volume on the radio is set to low, you can of course only turn up the volume on the amplifier to a limited extent).

Sorry Michael, don't know.
Tip: I returned the radio because the sound is too low.
Not ideal for SRF 1 where there is a lot of talking.

Hi Michael
Interfaces with the designation AUX (for auxiliary) were the first interfaces ever and are still widely used. Simply put, these are analogue audio inputs or outputs to which you can connect players of your choice.
I have not tried it myself.
LG Marcel