Or maybe a quick youtube video demonstrating the issue and stating in the comments about what has been tried so far. It is unlikely this symptom has never been heard before and others could offer suggestions. r900 not exactly inexpensive so would seem worth it to get some more ideas.
Help with kef r900 issue
I bought a pair of kef r900 speakers from kefdirect in April 2018. I enjoy them most of the time, but with some vocals, e.g., Alan Jackson, Allison Krauss and Mary Chaplin Carpenter, at nearly any level, they sometimes make a ripping, tearing or distorted sound that is hard to describe. Initially, I used a McIntosh MC202 with 200 rms, and now a Rotel RB 1590, with identical results. Initially, I used a very old Transparent Musiclink cable and now a Transparent Plus, again with identical results. I’m about to dump these unless I can figure it out since KEF has no one in the NW to repair them and they advise against paying to ship them (I agree). Before I write them off as a bad bargain, theories are solicited! Thanks