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...

 

 

nyev
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Hi Thyname,

The Grimm MU1 was at the CAF in the GTT Audio room. Bill was running it with Mola Mola gear and Vivid speakers. I wasn’t crazy about the sound it was a little bright. Maybe it was the Class D amps?
I have the Grimm MU1 and Mola Mola Tambaqui dac in my setup and the sound is wonderful!
 

 

I hate to say this, but Grimm was totally absent in CAF. I looked for it. Zero. I think the fad is dying up pretty quick. I love to be proven wrong. All the OG Grimm enthusiasts I know gave up on it. Admittedly my sample size is small 

@lalitk A public shout out to you. You have been very helpful and I very much appetite it. 

@lalitk Yes. When toggling between native and 4x it’s quite obvious. Have the JCat feeding it. I should try it without but nah.
Hope all’s well with you.

@wsrrsw 

Congratulations on acquiring MU1. Do you hear appreciable difference between native and 4x up sampled file? 

Also just got an MU-1 (replacing a Lumin x1) into a Weiss 501. Just thrilled. 4x over sampling! Who knew? Darling where you been?
My wife came into listen ( second time this month…stop the presses) and without me saying anything asked why it sounded so good. Buy her a drink.

It’s a better Roon box with playback that is more enveloping and all the usual superlatives.

Smoke ‘em if you got ‘em.

Hi Carlsbad2, now that the MU-1 has a few more hours of use, do you have any follow-on comments or preferences. 

I have the Dave, M-Scaller and Zenith MkIII and even though I prefer user experience with Roon, I prefer the SQ of the Innuos native player. A move to the MU-1 interests me as others have preference the MU-1 with Roon over the Zenith with the native player. Given you were using the Chord Dave, I wonder if that was your conclusion or if you ended-up on a different route. Thanks, Neil

Just bought an MU-1.  I've only had it 36 hours so I'm going to refraim from drawing conclusions but initial impression is very, very positive.  

I spent most of the morning reading this thread quickly and there is so much information in it that I had to skip over some of the bunny trails it goes down and will probably go back through it a bit later.  But great info here.  I especially appreciated the discussions by @nyev and @ghasley .

My old streamer is an Innuos Zenith MkIII.  My DAC in a Chord DAVE and with the old streamer I use the Chord M-scaler so count me in the pro-upscaling camp.  I'm not going to sell this gear yet as initial impressions can fade.  I'll put it back in service in a week or so and that should confirm.  Of course with the MU-1 I don't use the Mscaler.  Interestingly I was able to remove the following equipment from my rack:  1.  Innuos streamer.  2  Chord Mscaler.  3  NUC with Roon core running on it.  4.  Farad LPS for M scaler.  5.  LPS for NUC.  

I don't have a good AES cable so I'm listening to a $50 amazon cable I could get overnight.  I decided last Sunday to look at the Grimm.  60 minutes later I decided to try one, and 2 hours later I had bought one used. It shipped Monday, arrived Wed, and I'm posting this on Fri.  I have a better cable from DH Labs coming tomorrow but will look at higher end cables.  But just the step up to DH Labs from amazon should be big.

I pulled the fuse and the Grimm has a 500mA input fuse which is very small (sizing of fuses by OEMs is more Kentucky windage than science).   It is my opinion that this one is sized very tight to the load (even though the load is very small).  That's the long way of saying that I recommend a fuse upgrade.  I upgraded the fuse this morning and the improved detail and dynamics was obvious. 

I'll post more after I've had more time to listen.  I updated my system in my profile this morning so you can see what other gear I'm running if you care.

Jerry

Hi @nyev - Sorry if this was stated previously, but I am wondering if you were comparing the MU1 (running Roon) to the Innuous Zenith’s native player or Zenith running Roon?

Reason for asking is I find the running Roon (core or end point) to be a bit smeared and narrow sound stage on my Zenith Mk3, and the Zenith native player to be more 3D, wider, deeper and a tad bit of mid range dip with vocals enhanced and out front, which I think you noted in one of your posts, so I assumed you were comparing the MU1 with Roon to the Zenith with native player.

And given your conclusion that the MU1 was the keeper has prompted my interest in testing the MU1 too, as I like Roon for additional music information presented and clicking through for music discovery and would rather be using Roon as my primary player.

Thanks, Neil

Hi @nyev - I don’t have anything to add to the Hifi Advice comparison of the Grimm and Playback Designs piece, other than to say it’s consistent with my experience. I’ve been using the Playback with a stock Roon Nucleus and I’ve been very happy with it. Both the Grimm and Playback are excellent, I’m glad to hear you are having a good time!

@metaldetektor , I’d be interested in your assessment of how the new PBD differs in character from the MU1?  Those would be interesting to compare. But my journey on this front is over….for now!

 

I've only tested my MU1 with the generic power cable and with my Audioquest Hurricane so my experience is limited.  But I can hear a very big difference going from generic to the Hurricane. 

As an aside, I've read a few initial accounts of the sound of the Innuos Pulsar on WBF, as this product is finally available.  Of interest to me, is that a few have said the sound is dense, "bottom-up", full-bodied. One poster compared it with his Zenith Mk2 + PhoenixUSB and also supported that finding. 

Which I find very interesting as 1) I've found that I don't think I gravitate to that particular profile, based on my preferences, and 2) That is not how I'd characterize the Innuos Zenith Mk 3 + PhoenixUSB at all (light-on-its feet, airy, expansive when compared to others I've had in my system).

 

 

@calgarian5355 

 

My experience is consistent with yours. My aes cable is a 1.5m Shunyata Sigma v2. I have a Final Touch Audio power cable.

For those that own the Grimm MU1, what are your experiences with changes in the power cable?  My findings is that it didn’t make much of a difference in the sound. I currently use the Kubala Sosna Emotion power cord (a slightly warm cable imo). My friend lent me his Nordost Odin 2 and I didn’t hear much of a difference.  Changes in the aes/ebu cable however, resulted in big changes!

 

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@shkong78 I find those comments a little strange (Grimm doesn’t sound polite to me) but in any event, those two options are 2x the price of the Grimm.

If we’re talking about the same price class, the Playback Designs MPS-X is the interesting comparison. Having owned both Grimm and now PB, I have to say I prefer the latter, which takes nothing away from the Grimm which is an exceptional product.

@nyev If you are interested in trying the Purple Fuse on the Innuous, here is their link for changing fuses. https://innuos.com/kb/replacing-the-fuse-on-innuos-products/

 

Also, I think Marten speakers recommend Jorma cables, so Marten dealers will often also be Jorma dealers.  I think that's the case near me, reach out to Command Performance A/V in Falls Church VA to see if they can get them.

@w123ale , I’ve not had direct experience with combined DAC/Streamers, so I can’t say first hand whether separating the streamer from the DAC will help.  But on the accounts of many, many others, it sounds to me that there is a very large benefit.  That said, you might want to check out the updated info on the Grimm MU2, which is a combined streaming DAC, on their website.  The MU2 should be available soon.  The article on the Grimm site is interesting.

@nyev sorry if this has been covered already, but I’m curious on your thoughts about if there is an advantage of having a dedicated streamer between a Roon core and a Weiss 501 DAC. As you know the 501 is Roon ready and accepts an Ethernet cable. I’ve been running a fiber connection into a Sonor Optical module and an Shunyata Ethernet cable into the Weiss. This thread has gotten me wondering about moving to something like a Grimm. I have a high resolving system. 

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@nyev  

I have a Jorma, HIJIRI HDG-X, and borrowed my friends Tron. All three are excellent AES cables and would be happy with anyone. None blow away the other. The differences aren't night and day. The Jorma might be more open in the treble and hits a little deeper in the bass. The Hijiri and Tron sound more similar to each other. Their midranges are a touch fuller than the Jorma. They are all very open and transparent from bass to treble. 

I think it will be whatever cable has best synergy with your components! In my setup I like the Hijiri best, its a touch more natural and brings out emotions more especially with vocals. Probably will put the Jorma up for sale or just might keep it too. I do like what it offers.

Where do you live I might be willing for you to check it out. I also would like to hear your thoughts on the Sablon.

Like I said it is all highly subjective. I could live with any one and be happy!

 

Strange.  I don’t have that issue with my MU1.  I certainly do with other components in my set up but not the Grimm.

@nyev

Some use plumbers Teflon tape and find it works well. It also has an infinitely lower cost. Regards

 

BTW - great wrap up!

Back to the MU1. A point I forgot to mention, is that I find both the generic power cord that comes with it and also my Audioquest Hurricane to be looser in the MU1’s power connector socket than with most of my other gear. The slightest nudge will cause a disconnection of power. I absolutely notice an improvement in sound when I reposition and recenter the connector.

Am ordering these to solve the problem. Shunyata ships these exact inserts with their power cords to help with fit when needed.  Perhaps Grimm should too.  Have to order 100 but hey I’ll never run out.

 

It’s great to hear that things are settling and you are enjoying your journey. I compared the Mu1 to two major streamers. I can PM you my thoughts. I do not want to derail your thread.

Some developments, close to the end of this particular journey… I’ll say this right up front in case it gets missed below, but with my upgraded cables my Innuos PhoenixNET pairs beautifully with the MU1. With the new cables the PhoenixNET does not “overdampen” the sound like it did when I was using the basic cables. Here is where I am at:

  1. My Shunyata Omega AES and Sigma V2 XLR cables arrived, and have about 110 hours on them. Burn in was needed; things sounded good at first but vocals were a tad “canned” sounding. All better now.
  2. Compared to my prior entry-level temporary cables (Old green Cardas AES cable and Audioquest Red River XLR interconnects), the sound has really relaxed and opened up. High frequencies are coming through without being forceful or drawing attention - they are simply there, in a very relaxed way.
  3. Sound is more “suspended” now with far better positioning, space, and air - especially with vocals.
  4. The MU1 has more than caught up in one of the areas I thought my Innuos setup was doing slightly better in. The MU1 has become more expansive and open with a bigger sense of presence and scale.
  5. Midrange is more relaxed and expressive with more finesse. That hard midrange impact I noted previously is toned down, and in retrospect is not missed. This is better!
  6. This one is interesting. Before, I noted that my PhoenixNET didn’t pair well with the MU1. The sound was over dampened, and became dull and lifeless. This is not so with my new cables. It sounds awesome - tightens and clarifies everything without losing anything at all now! Not sure if there is any concern that the MU1’s network speed is 1000 Mbps while the PhoenixNET is limited to 100 Mbps. I will ask Grimm if this holds back sonic performance at all.
  7. Another interesting one. Before re-adding the PhoenixNET, I have to admit I wasn’t sure about the MU1’s oversampling modes. I was finding that on some tracks, vocals at center stage were not as solid and well-formed with 4X oversampling engaged. But after reintroducing the PhoenixNET, this problem went away! 4X oversampling sounds fantastic now in all cases, to me! More open, cleaner, more suspended feeling, with more space, and vocals are just as solidly formed at center stage now.
  8. As an aside I tried some sonic stabilizers that rest on top of your gear. Herbie’s. They changed the sound without a doubt. But not in a good way - sound became more condensed and compact. Will not use them.
  9. I did some comparisons feeding my original Diablo 300 DAC module using the Shunyata Omega AES. And it sounds truly fantastic! Had I tried this originally I would have been happy with this. But the Tambaqui is better - more detail, more precision, more expressive. But taking a step back, between the cost of the Tambaqui, the cost of the Sigma V2 XLR interconnects, and the future cost of a Dragon power cord, I’m not sure the value is there, considering how good the Diablo 300 DAC module sounds now that I have a premium AES cable. But the Tambaqui is without a doubt better, and since I already own the Tambaqui and XLR interconnects, I’m happy with them and they aren’t going anywhere. Debating whether to remove the DAC module from my Diablo300 amp, for a possible boost in quality due to less electrical noise in my amp.

Regarding the SR fuse for my Innuos Zenith Mk3, my dealer has not followed up twice after they had emailed they would. I’ll take that as a sign and give up on that. I may try SR purple fuses in my MU1 and Tambaqui in the future.

Regarding the Muon filter, now that the PhoenixNET is back in the mix, I won’t be going the Muon route. The PhoenixNET does filtering AND it is a reclocker for Ethernet.

As a very final step, I will be ordering a Sablon AES cable. Just have to hear this cable after several reports comparing with Shunyata, the most recent being from @svenjosh.

Really happy with where things seem to be settling out. It’s finally time to say goodbye to my beloved Innuos Zenith Mk3 and PhoenixUSB, and AudioQuest Diamond USB cabling. I can now remove the cellophane screen protector from my MU1 - it’s definitely here to stay!

My next upgrade (because yeah…) will be swapping out my Audioquest Hurricane power cords feeding my source equipment for Dragons. I currently have Dragons feeding my amp and Torus isolation transformer. Seems like a logical next step to me! Will not be anytime soon, will take it slow for now, aside from messing with the Sablon AES….

 

 

 

@snopro , just saw this now.  I had previously opened a ticket with Vana Inc from their website requesting the Jorma, but didn’t receive any response.  Can I ask, what other AES cables you have compared with the Jorma, and what differences you found?

Nyev, if you want Vana Ltd. in Nesconset, NY deals with Jorma cables.

I received mine from him and it is an excellent AES/EBU cable.

 

 

@essrand i tried to reach out to them but no one responded to my inquiry. Does it have Roon software built in?

@woots Have you considered trying Playback Design streamers with your Nagra Tube DAC, it will use the Nagra Link instead of AES or USB.

Thanks to @metaldetektor, its top on my list to try out now with my Tube DAC.

There are other reviewers who compared the Gustard R26 to Ares II and preferred the Ares II as being more organic and balanced. I’ve owned it for two days now in my second system, and so far I can say that it’s very good for the money. But giant slayer it ain’t. 

“I just get the impression that if you can compromise on the streaming functionality, the R26 sound quality is especially good.

@chopandchange

The OP is on a journey to push the limits of his digital streaming…don’t think he is in a compromising zone…LOL! You can certainly choose to save money and go for R26 and be happy. That’s the beauty of digital, one can enjoy sound from a very modest setup. Check out the YouTube video of Orchard Audio’s Pecan Pi + Streamer/DAC ($799.95) and Starkrimson Stereo Ultra Amp ($2499.95). This two components system sounded pretty darn good for the money when I heard it at AXPONA 2023. Just add speakers and you’re in digital heaven.

https://youtu.be/ymIoPm66FJo

@arafiq no I didn't expect the R26 to be close to the MU1 in terms of comparing the streaming side of things - I just get the impression that if you can compromise on the streaming functionality, the R26 sound quality is especially good.

You could put an MU1 ahead of the R26 of course using it as only a DAC - many are replacing the Chord Upscaler with the MU1 to save money, because the MU1 upscales especially well.

But saying all that - the R26 is a Roon endpoint, so this does help make up for the loss of it's own inbuilt streaming capabilities.

Anyway - as someone has said - I have not heard the R26 to make that comparison it's just an impression I get from a trusted reviewer who was bowled over by the sound of the Gustard. If the R26 ends up sounding as good as the review states - I would probably choose to save money and get the R26 over the MU1 and possibly enjoy my hi-end sound equally well.

I cannot backup the R26 review from experience and there are no dealers in the UK where I can try one out. I have heard the MU1 in a proper demo - and the MU1 is an excellent digital transport, probably about as good as you can get in that respect.

 

Thanks @lalitk . Definitely something to keep in mind. At times I wonder about mixing and matching too many different cable brands in my system and risking mismatches, vs leveraging single brand synergies. Not a big concern though, not by a long shot.

@nyev 

Network Acoustics also makes great sounding cables. Check out their latest Muon AES Cable. Something to keep in mind when you’re ready to order Muon Pro filter kit.  Another favorite of mine is Combak’s 聖HIJIRI Million HDG AES cable. 

@ghasley while I’m somewhat curious about the buzz surrounding Musetec and I don’t think these people’s experiences should be discounted (questioning is fine), it’s certainly not a priority as my DAC tick box is definitively checked with the Tambaqui.  I have zero reservations on what it adds to my system and can’t really ask for more at the present time.  So while I remain curious about the Musetec testing one is certainly not a priority for me!

What I do find fascinating is @svenjosh ’s enlightening findings on his AES shootout thread.  Extremely interesting he chose Sablon AES over Shunyata Omega and, shockingly to me, over Nordost Odin 2.  Whoa…. And he’s not the first to prefer Sablon over the uber-expensive cables either. Sorry this probably belongs on his thread but it’s sort of intertwined with my journey here too!

@nyev stick to your plan, overlay your goals and don’t deviate. Alot of well-meaning forum members are certain their giant killer server/streamer/dac/upsampler/reclocker is the answer to your prayers.

 

Only you can determine what will work best for you.

Yes unfortunately that seems to the case with Jorma, even some of the dealers listed on their website don’t carry the brand anymore.

Awesome, thank you @svenjosh !  I see that you as well were unsuccessful in securing a Jorma cable this side of the Atlantic.  I even tried contacting UK dealers and distributors, and Jorma directly.  They don’t seem to care about selling their products in North America.

Further to @arafiq post…those contributing here from their direct experience often ignore (conveniently) a fact that every system is unique just as our individual preferences. There are no absolutes in audio..nuff said!