I just received my MU2 on Tues of last week, and right out of the box it sounded horrible. The bass was,for the most part, non-existent and what was there was very compressed sounding. The midrange was ok and the treble was very bright. I'm now about 20 hrs in and the bass is now present and sounding pretty good, midrange is sounding real nice and the top end is still a bit bright. It's still a bit digital sounding at times. At this point my innuos Zenith/ Denafrips Terminator 2/Audio Research Ref5 combo sounds much more natural, so I'm hoping more break in time will reveal the magic of the Grimm that everyone is talking about. I've been using the MU2 preamp and haven't tried running it through my preamp yet. I'll wait untill it's further broken in for that. I'm hoping for the best,but at this point a bit underwhelmed.
I've been reminded of how much I didn't like Roon. Since buying the Innuos and using their sense app I've found that superior, so I'm hoping that Grimm will support Tidal connect in the future and come up with their own app. I have already had a couple of dropouts, and some clicks in between tracks on playlists and that's just unacceptable and I never experience that with the Sense app. Also, I can't access my Tidal playlists that I created. Roon does.have some nice features, but the negatives far outweigh them. Just my opinion.