I just upgraded from a K-03XD to a K-01XD se. An audio friend just upgraded from the the K-01XD to the K1X se with the stand alone power supply. He indicated it was an upgrade from the K-01XD and we think it was the power supply that added the most improvement. The question is how much difference is there between the standard K1X se without the power supply and the K-01XD. The K1X se has I think 7 more capacitors, probably a slightly different transport and the casework is a little more robust. I don't know about any clock differences. He did mention when he was using the external clock (the expensive one) with the K-01XD there wasn't a noticable difference in his system with it so he sold it. I think the external power supply makes the biggest difference but that gets very expensive with the K1X se player.
