Try running that latency checker sometime. It showed me some interesting differences between what I thought should be relatively equivalent computers.
I tried. The latency is consistently under 500nsec with DPC Latency Checker.
Also, I tried again the Sanskrit with my office PC. It has USB3 ports, and there is no USB2 port available.
The DAC does not work at all. It works (sort of) only with Wasapi PUSH, not event. Forget high res, nothing works in this case.
Also, my M2Tech Hiface 2 shows similar issues with this pc. I think it may be related to the USB3 ports, is it possible? I set buffers as high as possible in the device's own control panel. Nothing helped.
What really surprised me in the end is that on this pc, on the same usb3 port, the FiiO X5 (used as USB dac) works perfectly @ any sampling rate.
Maybe this can be due to the fact the FiiO works from battery and only uses usb power to charge its battery? Or its usb implementation is simply better?
Also, as I mentioned before, all this stuff works fine with my other work pc, which is a desktop with an old Core 2 Duo Q6600. No issues here on Debian Linux with the Sanskrit.
And, of course, the Sanskrit works at home on the Windows PC as well as with the linux dedicated music player.
Any further ideas to try?