I have tested Lumin D3 and I have the Eversolo dmp-A8 now. Here are my impressions:
Lumin is better built.
Lumin has higher output voltage (6V vs. 4.2V). This is a big difference and can be important if you are using the device as a preamp.
Eversolo sounds better. Lumin sounds good, but can sound a bit nervous sometimes. the bass is slightly boosted. Sound stage isn't as good as the Eversolo. Eversolo sound is tonally balanced, rich but also detailed, dynamic, but never aggressive, has better and wider sound stage than D3, only the depth could be a bit deeper.
Eversolo has DSP and analogue volume control.
Eversolo has a LPS and a SPS, Lumin SPS only.
Eversolo has much better connectivity options (even analogue inputs). Lumin has only an USB input for an external storage device and only a BNC output.
Eversolo has a remote control.
Both apps are very good.
Eversolo is 600 EUR cheaper.
I have returned the D3 and kept the A8.