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[mjw (Here I am with a brain the size of a planet and they ask me to pick up a piece of paper. Call that job satisfaction? I don't.)]

The following post may help explain what’s happening. Note the impact of applying just convolution on DSD256, and you are using DSD512.

Issue with Convolution of DSD Files in Muse Leading to Stuttering During Playback (ref#M5YE05)

It is likely that the processor in your Roon Server is not powerful enough to do the convolution on DSD files. If you look at the signal path in the Roon desktop or remote, you should see a value for processing speed. If this value is ever less than 1.0, then you are working (at least one core) of your processor flat out and it still can’t keep up with the processing that is being asked of it. In practise, the value moves around a bit and instantaneous peak values can be slightly lower than the…

Since I use PCM, I can’t offer much more assistance. However, if you want to proceed down this route, you may find some guidance in the HQ Player category.