I've followed the general consensus on here and switched over from usb to optical input on my Qutest. I bought a QED glass cable thinking I could take advantage of the 192KHz capabilities. I am shocked to discover that despite my computer being able to transmit a 192KHz file, Qutest's optical input maxes out at 96KHz. Even Dave has the same limitation but TT² can manage 192KHz that matches the cable. I'm disappointed.
I'm running Qutest optical connection 24bit 192Khz without a problem with sysconcept.ca cable and mac mini late 2014.
Chord Qutest manual also says that it is capable 24bit 192Khz or DSD64 via Optical. Check you cable or pc/transport....