In the second part of their MU1 review, hifi.nl’s Ruud Jonker takes a more technical approach to the MU1. But of course he also takes a listen… and becomes very enthusiastic:
“The arrival of the MU1 marked a bright spot in this time of downfall thinking. The device activates the hug hormone. You lower your pace and your senses go wide open. Therefore I present to you the Eindhoven alternative to the Shinrin Yoku.
The MU1 gives an astonishing insight into the nature of the recording. When a recording is of high quality, you are certain to receive a glorious and spectacular experience.
(…)
The CD playback via the MU1’s AES/EBU input offers a very relaxed sound quality. The low end is very good and goes extremely deep. The CD sound has no ‘digital’ signature at all and sounds realistic and ‘analog’. There is no sharpness whatsoever. The spatial reproduction is phenomenal and the sound is exceptionally beautiful. Listen to violins, cellos and pianos. What struck me is that the decay of tones is so easy to follow. This also made it possible to experience the decay of the acoustics very well.
(…)
I listened to a TIDAL stream and to music from the ssd in the MU1. Perhaps it is no surprise that the quality from the ssd is very good. I got the same results as with CD playback via the MU1. The very beautiful and deep sound, the ‘analog’ character, the lack of sharpness, the layering of the soundstage and the phenomenal details.
What did surprise me is that the MU1 was able to also render the external TIDAL stream to such a high level that it was hardly possible to hear significant differences between the stream and the playback of material from the SSD or connected CD drive. I played a CD track via the AES input of the MU1 and the same CD track came in via TIDAL, both ran as synchronously as possible. When switching it was not possible to hear any meaningful difference. This means that the clock electronics and the software that controls the conversion are of a very high level indeed.
(…)
In my opinion, the Grimm MU1 Music Player tops the sound quality of many (sometimes much more expensive) products from other manufacturers, and makes a natural fit with a number of sublime high-end systems that have been developed in the same spirit, such as Grimm Audio’s LS1. This is only possible when development is based on quality driven engineering and research and not primarily aimed at saving costs, pleasing shareholders and maximizing profit. The focus clearly has been on how one can get digital audio sound as natural and real as possible. Which is the only way to achieve real progress within the audio world. Those who stop listening technically will experience that the rendering of the MU1 is as natural as possible.“
Read the first part of the review here >

“The MU1 gives an astonishing insight into the nature of the recording.”
Ruud Jonker, hifi.nl