You are right. It uses an older ESS DAC chip, although I don't know if that makes you right about whether the transport's clock is used.
I will tell you one thing, I think the Moon 280 D was a deal. At least for me. It doesn't have a screen. The streaming interface is on an iPad or phone. It does not have a preamp or headphone amp. Just simple lights on the front telling the user the input in play and the quality (44.1, 48, 96, etc.) It does use, however, the same software as the more expensive Moon streamers. When I auditioned it I could not tell the difference between the 280D and streams costing more than twice its price. I didn't think I'd stream much, but I am doing more than I thought. I have heard better streamers, but this one errs in a musical way, kind of like tube gear. So, I'll keep it.

