Simon,

I've wrestled with this issue for a few years now through 568.1/568.2mm/G68.

I did some tests feeding my 598 through the G68 and directly to the DSP mains. Simply switching between CD and DVD on the MSR to select D1 or D2 inputs meant that you get an instant A/B comparison.

I don't want to quantify what I found but I can say that the G68 is not transparent - even when using direct and MRC off.

It's easy enough to setup via the DSP control menu. I'd be interested in others views. To re-iterate, I am not comparing MRC to non-MRC. Simply an SPDIF feed via processor and not.

Rgds,
Nick