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...




A used mint condition Mola Mola Tambaqui came up for sale from a Canadian distributor for a fair price, so I went for it. Really looking forward to listening to this pairing, comparing with the Diablo DAC, and comparing with my Innuos Zenith Mk III & PhoenixUSB.  The prior owner of my Tambaqui traded it in for a Kassandra.

I feel like this should be a winning combo (one of the designers who had a hand in designing the MU1 also designed the Tambaqui). Not too concerned buying the MU1 and Tambaqui unheard; these two products sell fast on the used market. But hoping I don’t have to go there!

My phone wants to enter “Tampon” every time I write Tambaqui.

Better get that autocorrect for "Tambaqui" fixed as I see you writing a lot about it in the future!

I’ve reverted back to causal listening mode for the past while while waiting for the MU1, Tambaqui, and fancy cables to arrive - just enjoying music. I tend to flip between states with the most time just listening to music.

But a day ago my used Tambaqui arrived. I couldn’t wait for my Shunyata cables to arrive, so I picked up a pair of Audioquest Red River balanced cables to try it with. The Tambaqui only has balanced output connections so I couldn’t use my RCA cables. My first impression after a day of listening - wow, I’ve heard this effect before! Will get to that later.

This is an utterly different sound than what I experienced with the Merason, with my Gryphon Diablo DAC, and with the Aurender N20. In fact this is at the totally opposite end of the spectrum from my experience with the Aurender N20. Here is what I found:

  • Unbridled resolution at all frequencies. Without being lean or bright!
  • Resolute, stable, rock-solid bass and mid frequencies. Density is great despite the extreme clarity.
  • Lighting fast. Like really, really fast. Transients are really, really quick but not at all hard
  • Neutrality compared to my Gryphon DAC module which has a boosted low end. So yes, the Tambaqui has less bass and for once I consider this a good thing with other elements being allowed to shine as they are supposed to.
  • More bass snap/punch
  • Imaging is fantastic with tremendous solidity with respect to positioning.
  • Everything is effortless and unforced, but lively and engaging
  • Really, really great connection with the music. Not sterile despite the extreme precision.
  • Better fine dynamics than my Gryphon DAC
  • My Innuos PhoenixNET Ethernet switch is a match made in heaven. It takes the Tambaqui’s sound and adds a focused liquidity to it. Although I guess technically it’s the other way around considering the signal flow.

Music is just fantastic and it’s actually tough to listen critically which is just great! This is clearly better than my Gryphon Diablo DAC module.

Are there any negatives yet? Two but these don’t bug me one bit:

  • Could use a touch more body to have vocals and instruments be “larger” - maybe? But maybe this would remove the space needed to do all the things it does so well. So I don’t really think this is a real criticism.
  • The space between vocals and all instruments is highly precise, but maybe with not quite as much distance between everything compared with my Gryphon DAC? With all of the positives I don’t even think of this as a negative, more of just a point of note. My Shunyata Omega AES and Sigma NR V2 balanced cables should help separate things when they arrive, not to mention the 4X hardware oversampling of the MU1. Which I’m told is in-transit finally!

Really liking this and feel it is totally aligned with what I am seeking. But it may not be for everyone. It reminds me of exactly the qualities that my Nordost Valhalla 2 speaker cables provided - detail that was really satisfying, delivered with lightning speed and without any lean-ness or hardness.

While this is right up my alley I could see how some may prefer a more fleshy and organic sound closer to what the Aurender N20 offered. But this is just perfect for me. And there is no tension or nervousness that my Gryphon DAC exhibits. It’s completely taken away my urge to tweak. I WILL tweak but because I will consciously do so rather than feeling compelled to do so. I haven’t even removed my speaker grills because it just sounds great and I’m too busy listening to music! This is effortless stress free listening - but with gobs and gobs of detail!

I know the less good things tend to come out with extended listening over weeks. But I really feel like I know this type of sound from my experience with my Valhalla 2 speaker cables, oddly, and that it’s totally aligned with my tastes. I would think that anyone who likes the Valhalla 2 speaker cables, which I know is not everyone, should really try this DAC. I know some people don’t like the Valhalla 2’s but I imagine some of these people may be exposing issues elsewhere in their system with the Valhalla 2’s and attributing the brightness they hear to them. Even in this thread I’ve been blaming issues on the wrong components only to find out later! On that note I’ve always thought the Diablo may not be the fastest sounding amp around but turns out it was the Gryphon DAC module holding things back.

The Tambaqui is clearly a cut above the Merason at more than double the price. But I will go back to the Merason to try it with the balanced interconnects. I still really like this DAC!

Will be interesting to see what the MU1 can do with my Gryphon DAC but at this point I’m guessing I’ll be stuck on the Tambaqui permanently. It’s perplexing how it can be so revealing while totally avoiding sounding lean and while being so musically engaging.

Oh and just for reference - this was all done with the USB output from my Innuos Zenith MK3 and PhoenixUSB.

Sound wise, I’d be totally happy if this was the end of the line. I could live happily with this sound.  But now I’m at +1 boxes until my MU1 arrives!





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.