I am using an original Hugo with DSD64 (1x) and DSD128(2x) with DoP with no problem. The computer is an ancient Netbook with a JMark of about 450, which may be the slowest MC computer in current use, running Windows 7. I do load files in memory to minimize disk reads during playback.
The stuttering you hear sounds like a CPU issue, especially if you hear it with 2x and 4x, but not 1x. Are you, by chance, using the DSD Encoding option in dsp studio? That would convert a DSD to PCM and back to DSD? That should be set to None.