If you're converting DSD to PCM you should probably do this before attempting playback and play the converted files instead. Reason I say that is because DSD to PCM (or PCM to DSD) conversions on-the-fly using DSP Studio are resource intensive tasks and if your PC isn't fast enough to handle it, you may encounter issues during playback like playback stopping and glitches.
To pre-convert files, right click on the file(s), Library Tools > Convert Format... and in the bottom of the tree you can pick the format to convert to along with the DSP settings (for Output Format set all to whatever you want) along with the bit-depth.
For DSD64 (from a SACD ISO or downloaded from sites like HDTracks and Acoustic Sounds) most tend to convert that to 176.4 kHz, 88.2 kHz or 44.1 kHz instead of 192 kHz, 96 kHz, etc. Do know though, DSD to PCM (and PCM to DSD) conversions are lossy and there is data/audio loss during conversion which is unavoidable. Some users don't like that it's a lossy conversion in which cases I do tend to recommend to people to avoid DSD content completely if they don't have a DSD-capable DAC or device capable of DSD playback without conversion and just stick with PCM content.