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...




@svenjosh what kind of DAC do you have? I've tried Shunyata, Audience, Transparent XLR and can't tell any difference fr Mogami. I have Weiss 501 DAC and SabrinaX.

@nadimjaber the dealer told me mu1 is best w aes.

Just ordered mu1 also. Will be here first week of May hopefully. The dealer also shared one of his clients decided to keep MU1. He had N20. Not sure if he's on here.

Thank you for starting this thread @nyev 



If your dealer is in Dallas, then, yes, that would be me. I took the MU1 out of my system and put the N20 back in. Love the N20 but the Grimm just works so much better with my system so I had to put it back in and buy it. The dealer was gracious enough to let me purchase the demo unit.

@nyev the OP, 

Did you try the SR purple fuse in your Innuos Zenith Mk 3?  I say try, of course because there is zero risk.  It can be returned.

I’m very interested to hear your thoughts on it, if you try one.

At the risk of overstating the matter, I pretty much think you’ve not really heard what the Zenith can do until you have put a purple fuse in.  For context, I added the purple fuse a couple of months after adding an ENO filter and EE 8switch with a Supracat ethernet connecting the two.  So, yes, I had some enhancements.  The fuse was and still is difficult to believe….for what it did.  To avoid…”jaw dropping” I’ll say that it will make you shake your head in incredulity.

Kidding aside, it is the biggest no-brainer among some very nice, high-value tweaks I’ve been lucky enough to discover.

And just to disclose the latest, I moved to the NA Muon filter and a NA ethernet cable to replace the Supacat 8.

Plan to add another purple or SR Master somewhere else in the system.

So I switched back over to Innuos (Zenith Mk3 + PhoenixUSB + PhoenixNET) from my MU1, yes three boxes instead of one, and have a few new insights after a day of listening, that maybe change some of my initial findings. Previously I had called the Innuos setup more open sounding, and I had said the MU1 has far more detail, among other findings as well.

These two particular findings remain valid, but I discovered the underlying reasons for them. With my Innuos setup there is a dip in the lower midrange frequencies that has now become obvious. This actually creates a sense of relaxed ease to the Innuos sound, and makes the sound seem to be more open as the upper mids and higher frequencies are more forward as a result. It also makes the lower frequencies seem to be fuller sounding as those frequencies also stand out more. While this effect creates a relaxed sound that is easy to listen to, because the lower mid frequencies are softer, these pleasing attributes come at the expense of softening the detail in this particular lower-mid frequency band. This is why I noted that electric (and other) guitars stand out more with the MU1.

The MU1 may be a hair more “precise” when it comes to eliminating any sort of bloom, and adding more texture, but my Innuos setup is surprisingly not that far off.

The biggest distinction other than the tonal balance difference I noted is just how driving and propulsive the MU1 is vs the Innuos setup which is gentle and laid back in comparison (but highly precise). I notice this effect most on how energetic the MU1 presents kick-drums and bass with a propulsive drive, vs the Innuos presentation where these elements are presented in a more gentle, relaxed manner while still being refined and precise.

Ultimately I’m still favouring the MU1, with its higher energy delivery with mostly equal performance or a hair better (with sonic presentation differences however) in a single box. Again this is prior to the fuse tweak for Innuos and prior to changing out my cables which I’m still waiting on!



@nyev You are correct the odin2 retails around 12k versus the Shunyata Omega at 4.5k, but the slight increase in the air and details make a difference for me and it is addictive. I wish I did not hear any difference, would have been better for my wallet. 

I am still not yet decided, waiting to try the Sablon this weekend and Jorma next week.