I put the DSDs on the internal memory. .DFF is the format for DSD? According to the site I got them from, they are a .dff file in 128 and 64 versions, neither of which have been found in directory view, out of three different files.
My file that did not work was in dff file extension, I converted it to Wave 192khz/24 bit instead to maintain hi-res, that obviously works. I did not find an anything file format to dsf converter but don't mind, cause the res is pretty good if not awesome