If the Toslink cable is connected to a Freebox Revolution, all channels are taken into account.
If the cable is connected directly to the optical out audio output of the TV, CAUTION, there is no sound for HD channels TF1, FRANCE 2 HD and M6 HD. Ok for others who claim HD channels (ARTE HD).
Works perfectly for MP3 files.
There is a slight loss of volume that does not bother me. Just increase the volume of the source or one of the amp.
I remember that the quality is perfect and allows to use a headset or amplifier optimally.