I hadn't seen that info about the HDCD issue but that wasn't causing the popping sound in my speakers; my 976 was having trouble accepting bitstream audio from all forms of movie discs but the popping was particularly frequent and louder with 4K/HDR discs. Switching to PCM output from my OPPO 203 resolved the snapping but not that the 976 wasn't performing as it was supposed to. Outlaw simply replaced my 976 with one they'd fully tested and I haven't had an issue since.