The digital coax cable the OP is using could also be part of the problem.
White paper.
Is The AESEBU / SPDIF Digital Audio Interface Flawed ?
http://www.scalatech.co.uk/papers/dunn_hawksford_1992.pdf
Yes, I know the paper is from 1992.
White paper.
Is The AESEBU / SPDIF Digital Audio Interface Flawed ?
http://www.scalatech.co.uk/papers/dunn_hawksford_1992.pdf
Yes, I know the paper is from 1992.