Alpha Audio: “MU1 touches the essence of the music”

We have the first official review of the MU1! Jaap Veenstra of the Dutch online hifi magazine “Alpha Audio” published a great review. For those who do not read Dutch, we translated part of his text and you can read it below. Mark that Jaap tested the v1.0 version of the firmware, v1.1 is on its way and will address the small user interface issues he had. If we read his verdict well this means the MU1 will then score 5 stars, just like he offered the LS1be…

After reading, please check this: mid October Jaap did a video interview with Eelco Grimm. We translated that as well so you can enjoy subtitles with the Youtube movie.

“The sound of the Grimm MU1 is … hard to describe if I’m honest. We compared the Metrum Acoustics Ambre streamer extensively with the MU1. And at first sight there seems to be just a little difference. But that appears to be a misjudgment since again and again we hear the same things happening: neutrality, extra resolution and especially: more space. If you listen carefully and don’t focus just on sound color, but also on the experience, air and ‘truthfulness’, you will soon find out that these are the unique assets of the Grimm Audio MU1. And after a few days it becomes clear how effortless the Grimm Audio MU1 plays. With it, the Focal speakers stage everything in a supple, natural way and in the right dimensions. The experience is stressless… If we then switch back and forth a bit, we note that we experience less listening fatigue with the MU1. And of course these are trifles, the Ambre is a true gem in its price class. But fact is: the Grimm Audio MU1 goes one step further. And it better does since it has eight times the price tag.

Back to the experience. We took a selection of test tracks. A mix of pop, classical, live and studio. It strikes us that the Grimm MU1 again and again shows how the track is recorded. Live does sound as live. Including the space, the room acoustics, the audience and the energy that comes with that. This is really exceptional, since especially that energy conveys a piece of music. We can hardly turn off Steven Wilson live in the Royal Albert Hall. We really hear the Royal Albert Hall. A great experience! To harvest these last bits and then communicate the energy and feeling, is an art… an art that just a few manufacturers master.


We listened briefly to the digital inputs. We connected the Ambre to the MU1 via AES and a Sony 810 Blue-ray player via S/PDIF. We then played a few tracks via the MU1 and compared that to a direct connection with the Pavane DAC. And indeed, when listening via the MU1 we hear the quality of… the MU1. The Sony sounds considerably better via the MU1 than when connected directly. That is a great result and proves Grimm’s claim is not just marketing. It is immediately audible that the FLL clock and upsampler still do their job.

“If we think about it a little more, the Grimm Audio MU1 manages to touch the essence of the music. The heart… the soul… the emotion. Can we call that subtle? No… in fact not.”

Jaap Veenstra, Alpha Audio


Some reviews write themselves. That can be in positive or negative sense – happily often positive. The Grimm Audio MU1 is not an easy catch like that. And that’s not because of the musical performance: it is exemplary. Rather because it is a challenge to find words for the type of playback and performance. That’s really difficult in this case. Because… how do you explain that the Grimm Audio MU1 brings on a feeling? That the difference with a normal streamer is not just a matter of sound, but of touching the essence of the music? Well… like that. And this is what we talk about with the MU1. We hope that Grimm will ‘dot the i’ in the software part soon. The MU1 will then be at the LS1be level…. in other words: flawless.”

Edit 29-1-20: Alpha Audio is now also available in an English edition, including the MU1 review.

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