The N01XD has a clock output which I could attach to the transport, I assume. I read this would enhance sound quality for CD playing.
The clock output in N-01XD is a Word Clock (not reference 10 MHz master clock), and can be set to 44.1 or 48 Khz. So it depends on what the clock input format on CD transport is.
As far the quality of the DAC in the N-01XD vs. K-01XD, it is the same DAC. However, connections, layout, wiring, etc. are different, accommodating just a streaming module in the N-01XD vs. an entire CD drive in the K-01xd. I have read from people in the internet that as a DAC alone, the N-01xd is better, but, don't take my word for it.