I haven’t touched the system in over a week, and when I noticed the noise (I had been listening for a while before I noticed it which is why when I did it threw me for a loop), I played a couple of other songs and only heard it on 1 or 2 of them. I then played a couple songs on CD and Brennan and did not notice it…Even Alvin from Vinshine thought it was I2S, but like you said I didn’t notice it on Coax or Optical.
Tomorrow I’m going to dive in head first and get to the bottom. I’m going to start by going direct with USB and then go from there and replay the same song(s) I noticed it…