I have the original K-05 and have listened extensively to the Marantz SA-10 in an ideal dealer audition setup using the same speakers, amp and preamp I have at home. There was no way I would part with the K-05 for the Marantz. It was clearly not on the same level. The K-05x has better DACs and other improvements over the K-05 so it will be in a different league than the Marantz it is safe to assume.