Here is some more information on the possible difference between dx100 and R10.
As we can see in the photo, R10 in the circuit after the DAC has OPA 827K.
Dx100 as I know has OPA 627 after DAC. But I've never seen a photo with dx100 audiotract where I could possibly see what is there in the circuit after the DAC, cause of the wiped-out OP name. If the information is correct, here is the main HW (besides SW) reason for the difference in sound. And yes, OPA 827 might sound better.
Like Anakchan and I already mention the different SQ , because of two thing
Different battery and op amp 627 on my HDP R10
In dx 100 I don't know what kind of op amp they use , because they wipe the op amp