I suspect that the reason it seems to make no difference is that there is none in your setup.
If you are using the digital output to the preamp/receiver, this option is to choose whether it is going to output DD and DTS along with PCM. You will either get an output or not and it will make no difference for PCM.
If you are using the analog outputs to the preamp/reciever, the setting is irrelevant.
If you are using the digital output to the preamp/receiver, this option is to choose whether it is going to output DD and DTS along with PCM. You will either get an output or not and it will make no difference for PCM.
If you are using the analog outputs to the preamp/reciever, the setting is irrelevant.