Yes please! I'm very interested.
Saaki, sorry for the late reply.
I've been experimenting with my Midgard. Please note the following:
1. I don't have a balanced cable yet to try out the Halo effect via the 4 pin XLR connector on the front. I have ordered a cable.
2. Some of the improvements come from other members here on Head-Fi and most of what has been suggested yielded improvements (big thanks to this community).
3. The Midgard is fronted by my RME ADI-2 DAC FS (AKM 4493 version).
4. Headphones used are Neumann NDH-30.
Here goes with the way I've improved the sound.
1. Using balanced cables from RME to Midgard. While I do think that SE sounds just as good through the Midgard, there is some easiness to the volume available to make the sound seem more effortless using my XLR cables. This is a subjective comment on my part. I did use SE for awhile and it was fine; I prefer Balanced.
2. The critical warm up stage.
I did leave the Midgard "on" one night and when I returned in the morning I found it sounded much better in its "warm" state. I am a firm believer it sounds better after one hour of run time from cold. YMMV.
3. I absolutely make use of the CrossFeed feature in my RME for headphone usage. I've settled at setting #1 (sometimes #2) on my RME DAC.
I remove the CrossFeed setting when listening via speakers.
4. I've settled on NOS filter setting on the RME. In all honesty, they all sound good with my fav being SD Sharp; SD LD and NOS (not in that order). It's a personal thing.
5. I have now started to make use of the PEQ on the RME to warm up the sound and this was surprising. Settings were suggestion I received here on Head-Fi and I just went with it. I could have used Audirvana's PEQ feature as well.
Here are the (some) settings that are working well with me:
1. Bass: frequency = 66 hz; bass boost = 4 to 9 db (9 was suggested and I did try it) depending on my brain and ears's mood; Q = 1.5
2. Mid-High: 7 kHz. -2.0 notch. Q =1.5
3. High: 10 kHz notch. -2.5 db. Q = 1.2
4. High: 14.3 kHz boost to compensate for NOS. gain of +3 db. Q = 1.2
6. Midgard is set in Hi-gain mode.
* As stated previously, HALO testing will begin once I received my new balanced cable.
As I type this I am currently using the RME + Midgard to power my Yamaha HS-7 speakers in near field (Crossfeed is off).
Listening to Herbert Von Karajan with the Berlin Harmonic Orchestra, Beethoven Symphonies using period specific instruments: Sounds Awesome!