"fuzziness" in TIDAL feed

I’m streaming TIDAL via the latest version of Roon (core and remote). My Core is connected via USB to my Schiit Modi Multibit, which is connected to my H/K Citation 17 preamp.

Lately I have noticed a certain fuzziness in the high end irrespective of the source (FLAC, MQA), which is driving me mad. Note that when I switch the Modi to another input (e.g., my Nakamichi CD player connected via the coax input) there is no issue at all.

What am I doing wrong, and how can I fix it?

Never mind! After ordering a higher quality USB cable (which I have been needing to do, anyway) I tried to isolate the issue by comparing the left and right channels. I found a bad tweeter in the right channel that was the cause of the problem. Good thing I had a spare!