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...




Glad you’re enjoying it. The Tambaqui is a great piece. Some criticize it as bright. I think it’s even-handed across all frequencies — if it’s bright when added to a system, there’s something else wrong in the system, in my opinion.

My system building approach is to go after neutrality/balance in all components. Otherwise you’re forever spinning your wheels (x has hot treble, let me add this rolled off component etc…that’s a recipe for endless tinkering - which is maybe the goal for some folks)

The Grimm will be a slam dunk. Especially with the Tambaqui. Keep having fun, that’s what it’s all about.

“if it’s bright when added to a system, there’s something else wrong in the system, in my opinion”

I agree @metaldetektor and that’s exactly my opinion of what people are experiencing when they feel Nordost Valhalla 2 cables are bright (although I found some of them have less bass but not the speaker cables). Revealing equipment can reveal other issues, and in fact the Nordost cables did for me - which took me down a major upgrade path over the past 1.5 years, one that I’m now finally feeling like I’m truly nearing the end of.  For the time being of course….

I completely understand how some might prefer a warmer, richer, fuller sound at the expense of detail, neutrality and precision, a sound that some might use the word “analog” to describe.  But yeah I think what you said applies to me - if I go that route I’m forever chasing issues.  It’s deceiving because the overall tone of the Gryphon DAC module is so pleasing that you don’t at first realize the trade offs.  And to be fair I didn’t start noticing them until my system became more revealing.



The reason I went with Shunyata cables in the end (Omega AES and Sigma NR V2) is because I was impressed by a home demo / bake-off I did with Shunyata Omega vs Audioquest Dragon power cords on my Gryphon integrated, a couple of years back.  The Shunyata was great even though I chose the Dragon, and the Shunyata had this lush, liquid smoothness to it with an immersive soundstage.  While still being utterly transparent and neutral.  And I’ve heard people say the same about Shunyata’s digital cords.  I thought this might come be a good match considering the high precision front end gear I’m adding.  

Regarding balanced interconnects, I know some say the grade of balanced cables doesn’t matter as much, and I know people feel YouTube HiFi comparisons are absurd.  But @jays_audio_lab replaced Transparent interconnects and compared with Sigma NR V2 balanced interconnects…  Listen to the intermittent high-hat after 4:30 and compare with the same after 11:00.  Easily heard on my phone speakers even, but more pronounced on my tiny desktop Bose computer speakers!

“It’s perplexing how it can be so revealing while totally avoiding sounding lean and while being so musically engaging.”


In my experience it is not! You are probably experiencing a complete transformation with Tambaqui DAC. A purpose built onboard DAC is exactly that regardless of its cost and not without its limitations which are only exposed once you have the opportunity to compare it with a well executed SOTA DAC like Tambaqui. You know the age old debate, Integrated vs Separates. There is a reason why separates (pre, amp, DAC, streamer) continues to exist and thrive in high performance systems. I read somewhere not too long ago, unless you’re a true music aficionado, an external DAC or a streamer is just an additional expense…..well what do you say to that :-)

You started out this journey by stating something like, “I prefer not to add more boxes and the additional expense of cabling”. The million dollar question now is, once you’ve heard Tambaqui DAC + MU1 at more than twice the cost of your existing setup, will you be going back to Innuos + Gryphon DAC? Is this Transformation worth the additional cost?????

H @lalitk , “transformative” is a good word that I would apply to how I would describe the magnitude of difference that the Tambaqui brings. That said, I normally would use that word for when anyone, not just me, and not just audiophiles, would notice the magnitude of difference in quality. Upgrading my speakers did that in my house. As did my amp. But my family has not commented on the sound since adding the Mola Mola. That said, for me, I continue to be amazed. It’s got the quietness of a high end power conditioner, but none of the constraints on the sound that I found those products all are affected by. And it just gets closer to the sound of actual music vs a digital HIFi system. This morning I did a few back and forths with my Gryphon DAC, which lists for USD $6,000. My initial reaction to going back was “oh that is nice and smooth sounding”. But one moment later I was realizing that the smoothness was simply less musical information coming through, that the sound was less defined, that the bass was more big and round but far less resolute and driving, and that it was tougher to follow the music.

My objectives did evolve in this thread based on discussion, thanks to @ghasley’s suggestions. That said, I only expand the number of cables significantly if I stay with my Innuos server + reclocker solution. If the MU1 is better, it will replace both Innuos boxes and I will be at the same number of boxes as I was at when I started out. The balanced interconnect was an extra cable however.  There is still an off-chance that the MU1 will lift the Gryphon DAC to the extent the Tambaqui is not needed.  But I think the chances of that might be slim.

Currently, the Tambaqui is feeling really special; I like it as much as my Gryphon amp. I’ve not felt that way about any other components in my system, even though some do a really excellent job too (PhoenixNET, Torus, etc).

Back to the MU1, it will be interesting if it is an upgrade from my two Innuos boxes. Christiaan at HiFi Advice has said that subsequent revisions of hardware, software and Roon have changed the MU1 since his review. And one comment I saw was that Roon 2.0 did cause the MU1 to become more subdued which was less to his liking. He said he’s stopped using the MU1 as a lead reference because of how Roon updates can cause swings in sound quality. One disadvantage of the MU1 to be aware of I guess. At least, until Grimm provides alternative and more stable sounding player software support as an alternative to Roon.