Could anyone tell me in what circumstances you would use the USB output (in settings) with PCM or the other option of DoP. I have found from some searching that DoP (DSD over PCM) is a format created by iRiver and is basically a DSD signal in a PCM transport... But in respect to using the SR15 options I cannot seem to find a situation or reason where you would select one over the other unless the equipment you are using the SR15 doesn’t have the PCM capability... Is that the only possible reason or are there others? Also in the same settings folder you can select or deselect MQA decoding software... Is this to be selected when using the SR15 with a laptop computer etc that has been loaded with A&Ks MQA software driver? And if you are not using the USB output other than as an OTG source with a Mojo does it matter what these options are set to? Thanks Guys.