How are you playing the DSD files?
As an ISO loaded into Audirvana Plus' playlist window?
If you are adding DSF to iTunes using a shortcut type method which makes the DSF file appear as an M4A, A+ has changed their alias method. In the older versions, it would play the same shortcuts created by Pure Music (.M4A) but this was changed to a new method in later versions. I gather this was because Pure Music sought an injunction and forced them to change the method. Shame really, I was using PM to make the DSF alias M4A files and using A+ to play them for the longest time.