The deq2496 placed between the transport and dac does not seem to degrade the sound in any way, introduce glare or grain or anything like that. Even if you don't use all the EQ sections, just reducing the gain and increasing the stereo width makes a sonic improvement in many cases. Just avoid the A/D, D/A conversions.
Which Digital processor/equalizer ?
Any experience from low cost beringer ultra to the audyssey pro or any other type. Most seem to do the same thing but have big monetary discrepancies