Could I recommend you for an DC-06 from Ibasso ? That thing drives even HD800S !!!
I am looking into the DC06 after you mentioned it. Based on reviews I've seen (so far), it seems they prefer the sound quality of Questyle M15 and Cayin RU6 more. M15 for clean crisp and somewhat musical sound, RU6 for very musical sound. I can't find comparisons to Moondrop MoonRiver2. (Although I read RU6 and MoonRiver2 drain battery fast). Ofc, these reviews are never too detailed, so I can't make decision yet.
Btw, did you mean in your previous post DC06 sounded better than DX320 plugged into your laptop?
If you have had issues with the Amp13 card (400mW@32ohms) pushing your headphones well, then the DC06 has less power than the high V output and will also not cut it (320mW@32ohms balanced).The DC06 is excellent sounding. Plenty of power with 3.5 and 4.4 balanced out. And can easily compare to units costing 300 dollars and bettering most dongles on the market. IMO
On the other hand, it does seem pretty capable for lower impedance headphones, and certainly IEMs. It looks comparable (in all but bells and whistles) to this but at 1/3 the price apparently.