Deane,

To me, the KMA sounded "richer, and clearer" and had a more 'crisp, sharp' sound.
Seems like the KMA (or the recording setup) had more mid and high tone amplification. The 600 had more of a flat, muffled sound.

Were they both "out of the box" recordings with no other resources, and were the EQ settings the same? The 600 sounded a bit like a PSR-3000 default flat EQ setting. (Not very good)

Bottom line, based on what I heard through my 3.1 HK computer speakers, overall, the KMA sounded better.
There must be a way to setup the 600 to sound as good or better than the KMA.