The clipping is there on both analog and digital outs.

Interesting!

And you have verified that it goes away with a flat EQ?

You can e-mail the WAV file to tfabris@oro.net at your convenience. I'm now broadband at home so the file attachment size is not a problem. Will this WAV file be some kind of a genuine digital grab from an S/PDIF input?

Thanks for doing this for me. I will run the WAV file through SpectraLAB and see what it tells me about the frequency distribution.