Grimm MU1 Streamer - Really "The Best"?

I've recently become interested in the Grimm MU1.  While reviews of top end players from Innuos, Aurender and Antipodes and others are typically all very positive, the tone of the many pro reviews of the Grimm MU1 go far, far beyond, with some reviews resorting to using superlatives and gushing of positive system transformation and not being able to stop listening to material, etc..  HiFi Advice and Steve Huff (actually calls it "magic") have such reviews.

Given the delay in availability of the Innuos Pulsar which I'm told will be better than my current Zenith Mk3 + PhoenixUSB reclocker, I am interested in replacing my streaming setup with a one-box solution that includes a high-precision clock.  The new streamer will continue to feed my Gryphon Diablo 300's DAC module, which I have no interest in replacing.

I'm actually a fan of Innuos, after they improved the sound of my Zenith with firmware updates and after I added their PhoenixUSB reclocker. I appreciate this commitment to improving sound quality which is why I was so interested in the Pulsar.

The trigger for considering an upgrade is not for improved sound, but rather, to solve some issues I have with too many Audioquest power cords coiled and clumped together. I will get to lose one of them and one of my USB cords with a one-box streamer. I've noticed my sound is very sensitive to positioning of my AC cords and find I often need to re-adjust the PC feeding my amp to get proper sounding vocals at center stage.  One of my subs also seems to be picking up AC noise when the crossover is set above 60Hz. The second trigger is simply system simplification, removing one box.  All that said I don't really have any complaints regarding sound, and the PhoenixUSB reclocker truly did improve the sound of my Zenith.

While the Grimm MU1 has it's 4X upsampling up it's sleeve with reviewers absolutely glowing over this feature and it's extreme ability to separate tones to the left, right, front, and back far better than the rest, I don't see that Grimm has gone to any lengths with regard to power supply management in the way other brands do including Innuos. The MU1's ultra-simplistic interior doesn't bug me, but the lack of transformers and power management makes me wonder....

Are there any updates from folks who have directly compared the MU1 vs similarly classed streamers from the competition?  Did you find it to be as revelatory as the pro reviewers found it? And, how does it compare to other streamers with it's 4X upsampling disabled?  Does it sound like it suffers from it's lack of power management?  I do see that the clock should be very good...




“I have used the same make of excellent AES cable, with different lengths (both 1.5m and less than 1.5m), in my rig and I cannot distinguish the difference.”

@metaldetektor I expect it depends on your DAC’s jitter rejection abilities as to how much of an issue this is.  Also, while I clearly heard the difference when comparing the same USB cable of different lengths, I do wonder if maybe USB is more susceptible to this issue than AES.  Of note, I tested two Nordost Valhalla 2 USB cables of different lengths, and I also heard the same effect when I tried a .75m Audioquest Diamond USB cable vs my 1.5m versions of the same cable.

“The Grimm and Innuos were very popular at Axpona this weekend. As good as they sounded you went into a room with vinyl and they are still not quite there.”

I heard that Innuos was showing off the Pulsar (although not a functioning demo?).

And yes, I wouldn’t expect that we’d be quite at the level of analog enjoyment in the digital world quite yet…. Maybe one day, maybe never!

Hi, Different sources, different sounds. It's that easy. Just as not all dacs sound the same, and not all turntables sound the same, the different sound formats will have their own imprint and each one is free to choose the one they like best. Which and in summary is a matter that in many cases is subjective and there, particularly, I do not enter


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About Sablon cable: I have the Sablón USB cable and it is a cable with which I am very satisfied in terms of its sound result. Highly recommended. That does need an adaptation period of many hours.

There is a difference between AES cables that is easy to hear when you go back and forth. But the difference is not as significant as other interconnect cables. 

I found that a high quality aes/ebu cable was a worthwhile investment but it isn’t night and day “a veil was removed and my wife walked in and asked what changed” kind of improvement. It matters but its the last thing to address rather than the first.

The digital link is crucial. It's the first thing I would address.

I personally wouldn't invest in a high end dac and server, and not have a reference digital cable.

Maybe the digital AES cable people have tried on this thread were all on the same level.

The digital cable I am using made all other digital cables I've tried sound broken. When I first heard it, my jaw dropped. I thought to myself, how is this even possible, when it's just digital bits?

@woots You should have compared the Grimm to the new Lumin models with the new processing engine. It's a huge step up from the older Lumin models.