Article: Grimm Audio MU1 Music Player Review

[PYP]

17 hours ago, 57gold said:

Still not sure I understand its functions / capabilities.  The company's website seems to indicate that it is a DAC 

When I was trying to get a handle on what the MU1 is, it was helpful to understand that it is a digital device only -- it contains no analog processes like your DAC has.  

 

I think of it as a DDC + server (either 2 or 8 TB storage) + streamer that also has a volume control (if you wish to use that; I don't).  As others have mentioned, attaching it a DAC is very simple as is getting Roon up and running.  

 

There is a web interface which allows you to try 3 different oversampling options, so trying out these options is rather simple (Chris then took it another step in examining the interaction with DACs that have various filters, which I think is valuable information for a prospective buyer).  Or, you can just use the Grimm suggestion of 4fs and enjoy it.  

 

My Tambaqui DAC is also a Roon endpoint/streamer (no filters available).  I was using the ethernet input.  The Tambaqui is a very fine DAC and the streamer was very good, but using the ethernet input required ethernet cleaners placed before the DAC to sound its best (which is pretty darn good).  

 

The Grimm doesn't need those cleaners, at least in my setup and according to my preferences.  And the Grimm's special sauce adds an inviting musicality that is even better than the Tambaqui alone (I was doubtful about this).  When I was considering the Grimm and adding up the dollars it seemed beyond what I wanted to spend.  But an in-home demo blew away those doubts.  It is truly a special unit.  

[Flashman]

Two thoughts:

1) A friend of mine says that the Tambaqui DAC with the Grimm MU1 is the best digital system he's ever heard.

2) For a few years, Grimm has been touting an upcoming MU2, which would add a DAC.  As it's been some time, I suspect the Grimm folks are having some issues.  Did you hear anything about a MU2?

[The Computer Audiophile]

5 minutes ago, Flashman said:

Two thoughts:

1) A friend of mine says that the Tambaqui DAC with the Grimm MU1 is the best digital system he's ever heard.

2) For a few years, Grimm has been touting an upcoming MU2, which would add a DAC.  As it's been some time, I suspect the Grimm folks are having some issues.  Did you hear anything about a MU2?

Here is info about the MU2, straight from Eelco Grimm. 
 

https://audiophilestyle.com/forums/topic/58754-grimm-audio-mu1-server/?do=findComment&comment=1215325

 

[Flashman]

6 minutes ago, The Computer Audiophile said:

Here is info about the MU2, straight from Eelco Grimm. 
 

https://audiophilestyle.com/forums/topic/58754-grimm-audio-mu1-server/?do=findComment&comment=1215325

 

Ah, thanks for the information!

[soupcon]

Appreciate this review. The MU1 is the most consequential audio expenditure in a long time. I spend a lot more time enjoying music than I have in a long time. 

 

 

[The Computer Audiophile]

9 minutes ago, soupcon said:

Appreciate this review. The MU1 is the most consequential audio expenditure in a long time. I spend a lot more time enjoying music than I have in a long time. 

 

 

Great to hear @soupcon

[FredM]

On 10/26/2022 at 8:27 PM, The Computer Audiophile said:

Audio that sounded great through the MU1, but with oversampling turned off via its web interface, was what I'll call piano music.

 

After testing various settings in and outside the MU1, you mentioned that you preferred the non upsampling (0fs) setting in the MU1 with piano music. Calling the transient in the Midnight Sugar track ‘overly sharp’ and even ‘the piano can rip the listener’s ear off’. It got me curious and also puzzled. I’ll try to explain: Although I have preferred the 4fs upsampling since the first day with the MU1 (and actually never touch it since), I tried if I could reproduce your findings. Well, long story short: no. On the contrary actually. I downloaded Midnight Sugar the album (great album btw, thanks!), and must say that I clearly prefer the 4fs setting compared with the 0fs setting (didn’t brother with the 2fs setting). This said, I’m not questioning your findings. But find it interesting what makes that things differ. And thinking more about it, I wonder if the way of testing could have anything to do with it.

 

With upsampling enabled to me it just sound more alive, with more air around the instruments. Also smoother, in a positive way. The strike of a piano key is easier to hear and the tones have a beautiful decay (longer lasting than in a 0fs setting). In more complex pieces, multiple tones just ‘flow’ next to each other and fade out gradually individually. In the specific section (2.25) the piano key is struck hard (and recorded close by?), but the clarity and flow remain. In the 0fs setting it sound (a bit) harsher for me, with less ‘flow’. I would call it an obvious difference (easy to pick in a blind test). Or could the higher Dynamic range (15) of the specific track have something to do with it?

 

With other music I have the same findings, no matter the genre or instruments playing. In my case 4fs is just better, more organic, it opens up, enable the flow. I even listened at some other ‘piano’ tracks to compare. The 4fs benefits remain:

- Nicolas van Poucke, The Schumann collection - Vol 1, Arabeske Op. 18 (modern recording)

- Joan Baez, The very best of, If you were a carpenter (older recording)

- Elbow, Build a rocket boys, Lippy Kids

 

 

On 10/26/2022 at 8:27 PM, The Computer Audiophile said:

The evaluation process I used involved setting Roon's upsampling to 2x or 4x, setting the MU1 to no oversampling, setting the DAC 200 to any number of filters or no filter, then listening, then setting Roon to no upsampling, then the MU1 to 4fs oversample, then listening, then trying a different setting or DAC, etc... The number of combinations is enough to drive anyone crazy. 

 

Once experiencing the 4fs setting, for me there would be no way back to 0fs. All this of course in my setup with my preference, but still our findings quite differ. Hence my confusion. Could it just be a matter of personal preference, or could specific variables result to the different upsampling findings? Perhaps a more general subject is touched (not specific to the MU1). You mentioned that when using additional filter settings,the filters are based on musical content which allows switching between filters depending on the music. Quite a part of the finding cover upsampling/tuning outside the MU1, it would be valuable to understand what relates to what, and ultimately why in your case 0fs is preferred with piano music.

 

With countless tuning combinations possible (filter settings, DSP, convolution setting, upsampling inside the DAC, etc), it’s hard to pin point things. Perhaps double upsampling (in MU1 and T+A DAC 200) can lead to mixed results? Or can early stage digital room correction influence the outcome? When using a specific settings/tuning methods for various types of music, could there be something like a too high level of detail so that it becomes too specific for a review in general? I don’t know. Would it be similar when during a review of for example a Power amp the power cord is swapped for music type A, and even a different pre amp is used for music type B. Besides difficulty in reviewing the product itself with the external variables, as a reader it will also be more challenging to get an understanding of the performance of the product (like I have at the moment 😀 ). Perhaps my hifi tuning knowledge is far below average, but I wonder to what extend an average listener/ reader uses these tuning options in practice (and apply specific tuning for specific music).

 

Looping back to the Grimm MU1, I think it would be interesting if you can try out the Midnight Sugar track with perhaps the tracks above and see how they sound in a minimalist setting (Without the DSP, filters, etc, etc.) Keep it simple. I think that would be closer to (most) users situation, better to understand and more valuable insights. 

 

Please don’t get me wrong, at first I liked your to approach as a welcome addition to existing reviews. But some results seem to differ quite from what others experience (by MU1 users and other reviews). As a suggestion, perhaps it’s an idea to simplify the evaluation approach for gear and perhaps have a separate paragraph for those who have interest and understanding in advanced filter/tuning settings?

 

[The Computer Audiophile]

8 hours ago, FredM said:

After testing various settings in and outside the MU1, you mentioned that you preferred the non upsampling (0fs) setting in the MU1 with piano music. Calling the transient in the Midnight Sugar track ‘overly sharp’ and even ‘the piano can rip the listener’s ear off’. It got me curious and also puzzled. I’ll try to explain: Although I have preferred the 4fs upsampling since the first day with the MU1 (and actually never touch it since), I tried if I could reproduce your findings. Well, long story short: no. On the contrary actually. I downloaded Midnight Sugar the album (great album btw, thanks!), and must say that I clearly prefer the 4fs setting compared with the 0fs setting (didn’t brother with the 2fs setting). This said, I’m not questioning your findings. But find it interesting what makes that things differ. And thinking more about it, I wonder if the way of testing could have anything to do with it.

 

Hi @FredM this is fantastic. This is what it's all about. Read what I have to say, then listen for yourself. Never take what I say about my experience, with my ears and my system n my room, as the gospel. 

 

Part of what this boils down to is which initial stage upsampling is preferred by the listener, that of the MU1 or that of the DAC being used. There's no right or wrong. 

 

 

9 hours ago, FredM said:

With upsampling enabled to me it just sound more alive, with more air around the instruments. Also smoother, in a positive way. The strike of a piano key is easier to hear and the tones have a beautiful decay (longer lasting than in a 0fs setting). In more complex pieces, multiple tones just ‘flow’ next to each other and fade out gradually individually. In the specific section (2.25) the piano key is struck hard (and recorded close by?), but the clarity and flow remain. In the 0fs setting it sound (a bit) harsher for me, with less ‘flow’. I would call it an obvious difference (easy to pick in a blind test). Or could the higher Dynamic range (15) of the specific track have something to do with it?

 

What this seems to say is that the upsampling to 4fs in the MU1 is either better than in your DAC or preferred by you more than what's in your DAC. All good. 

 

 

9 hours ago, FredM said:

With countless tuning combinations possible (filter settings, DSP, convolution setting, upsampling inside the DAC, etc), it’s hard to pin point things.

 

Absolutely!

 

 

9 hours ago, FredM said:

Perhaps double upsampling (in MU1 and T+A DAC 200) can lead to mixed results?

 

It isn't double upsampling technically. It's upsampling in the MU1 to 4fs, and in the DAC 200 to its max rate. The first stage is done in the MU1, the rest in the DAC 200, versus all in the DAC 200. Different filters and algorithms should sound different. Both of us have definitely heard this :~)

 

 

9 hours ago, FredM said:

Besides difficulty in reviewing the product itself with the external variables, as a reader it will also be more challenging to get an understanding of the performance of the product (like I have at the moment 😀 ). Perhaps my hifi tuning knowledge is far below average, but I wonder to what extend an average listener/ reader uses these tuning options in practice (and apply specific tuning for specific music).

 

I hear you loud and clear. I really wanted to be able to deliver some clarity, but it just isn't possible with so many options. The only thing I could do was try many of them, and describe what I heard. It's great that you and others have described what you/they heard with the MU1 as well. More data points are good. 

 

 

 

9 hours ago, FredM said:

Looping back to the Grimm MU1, I think it would be interesting if you can try out the Midnight Sugar track with perhaps the tracks above and see how they sound in a minimalist setting (Without the DSP, filters, etc, etc.) Keep it simple. I think that would be closer to (most) users situation, better to understand and more valuable insights. 

 

The MU1 is heading out the door today, back to @Analog Audio of Minnesota

 

 

9 hours ago, FredM said:

Please don’t get me wrong, at first I liked your to approach as a welcome addition to existing reviews. But some results seem to differ quite from what others experience (by MU1 users and other reviews). As a suggestion, perhaps it’s an idea to simplify the evaluation approach for gear and perhaps have a separate paragraph for those who have interest and understanding in advanced filter/tuning settings?

 

No worries. I know you have th best of intentions and it all comes from a good place. The fact that my results are different, is kind of nice to me. I feel very different from most other writers. Not better, just different :~)

 

All feedback and recommendations noted. It's all valuable. Thank you.

[FredM]

6 hours ago, The Computer Audiophile said:

The fact that my results are different, is kind of nice to me. I feel very different from most other writers. Not better, just different :~)

 

All feedback and recommendations noted. It's all valuable. Thank you.

Thanks for your responses @The Computer Audiophile 👍 
I guess I’m trying to understand why -per type of music- you seem to prefer different upsampling settings (0fs / 4fs). But fully agree, we just have different findings, all good.
 

Great that you’ve had the opportunity to experience the MU1. When it arrives back at @Analog Audio of Minnesota it can do its magic and create smiles on a lot faces again 😀, nice to occasionally see new MU1 users in the Grimm MU1 topic.

 

[Analog Audio of Minnesota]

3 minutes ago, FredM said:

Thanks for your responses @The Computer Audiophile 👍 
I guess I trying to understand why -per type of music- you seem to prefer different upsampling settings (0fs / 4fs). But fully agree, we just have different findings, all good.
 

Great that you’ve had the opportunity to experience the MU1. When it arrives back at @Analog Audio of Minnesota it can do its magic and create smiles on a lot faces again 😀
 

thank you for the kind words. I already have one in my main gallery room so this one is heading to a new home. Not to mention I have an evaluation unit on-hand for clients.

 

And yes, it creates smiles whenever anyone experiences it.

 

[The Computer Audiophile]

20 hours ago, FredM said:

I guess I’m trying to understand why -per type of music- you seem to prefer different upsampling settings (0fs / 4fs).

 

This is actually very common. Here is page 22 of the dCS Vivaldi manual. You can see why people may prefer different filters and type of music may be considered when selecting a filter.

 

 

[fas42]

Quote

On the title track to Midnight Sugar, there was also more definition in the top end and the transients were less sharp with the MU1's oversampling disabled. Specifically, the transient at 2:25 into the track. With 4fs oversampling enabled, the piano can rip the listener's ears off. It's overly sharp. Without MU1 oversampling enabled on this track, the T+A DAC 200 with bez2 filter sounded fantastic, as did the EMM Labs DV2. When listening to piano music, I preferred the T+A and EMM Labs filters and algorithms on their own. 

 

Very strange recording balance to the piano; I've never heard a live instrument present so much 'power' in the transients - did they place a microphone right on top of the right hand strings?

 

Is this typical for how TBM record the sound of the musicians?

[The Computer Audiophile]

20 minutes ago, fas42 said:

 

Very strange recording balance to the piano; I've never heard a live instrument present so much 'power' in the transients - did they place a microphone right on top of the right hand strings?

 

Is this typical for how TBM record the sound of the musicians?

This is the specific version I listen to. 
 

https://www.impexrecords.com/midnight-sugar/

 

[Low325]

Thanks for the review!  

I haven’t posted as much since creating an account but its great to see a high concentration of MU1 experiences and owners here.  I have a MU1 on the way.  I’ll be moving away from my all in one streamer DAC so till I get another DAC I wont be situated with enjoying the new capabilities.

[dctom]

I purchased a MU1 last year after a long comparison with an Innuos statement. For several years I have been using my DIY server (recently upgraded with new MB and  i7-13700cpu) based on the Audiophile style server building threads - A novel way to massively improve the SQ of computer audio streaming / Building a diy music server (Nenon et al). Running  Audiolinux and HQplayer utilising the Taiko ATX-DC and powered by a P Haynes SR7, silver wired, turbo. It sounds excellent, so good in fact I sold my vinyl set up of Kuzma XL 4pt, Lyra Atlas and Ypsilon phono stage.

It also compares very favourably to the Grimm, however the Grimm just seems more natural and adds a better sense of flow. 

I was interested to see some owners use the MU1 as an end point and wondered what the set up proceedure is to achieve that? I would be interested to try out using my server streaming to the MU1 - at least it would not be redundant, although I might be able to sell it.

Something I have tried with the MU1 is play an old CD player (Pioneer 802 - plays CD inverted)  through it via the CD  player's SPDIF out. The result is quite amazing the CD virtually equals the same file ripped to HD when played through the MU1. 

I have the MU1 connected to my Mola Mola Makua pre, which has a Tambqui DAC module incorporated, via AES. So my assumption is the Grimm's clocking and FPGA are improving the CD player's signal dramaticlly prior to sending the information to the DAC.

[krass]

On 2/3/2024 at 3:12 PM, dctom said:

I purchased a MU1 last year after a long comparison with an Innuos statement. For several years I have been using my DIY server (recently upgraded with new MB and  i7-13700cpu) based on the Audiophile style server building threads - A novel way to massively improve the SQ of computer audio streaming / Building a diy music server (Nenon et al). Running  Audiolinux and HQplayer utilising the Taiko ATX-DC and powered by a P Haynes SR7, silver wired, turbo. It sounds excellent, so good in fact I sold my vinyl set up of Kuzma XL 4pt, Lyra Atlas and Ypsilon phono stage.

It also compares very favourably to the Grimm, however the Grimm just seems more natural and adds a better sense of flow. 

I was interested to see some owners use the MU1 as an end point and wondered what the set up proceedure is to achieve that? I would be interested to try out using my server streaming to the MU1 - at least it would not be redundant, although I might be able to sell it.

Something I have tried with the MU1 is play an old CD player (Pioneer 802 - plays CD inverted)  through it via the CD  player's SPDIF out. The result is quite amazing the CD virtually equals the same file ripped to HD when played through the MU1. 

I have the MU1 connected to my Mola Mola Makua pre, which has a Tambqui DAC module incorporated, via AES. So my assumption is the Grimm's clocking and FPGA are improving the CD player's signal dramaticlly prior to sending the information to the DAC.

 

I have same setup (Mu1 and Makua with DAC).

 

I think you’re correct.. that config takes advantage of the Mu-1 upsampler & transfers 4fs (or whatever you’ve configured) to the DAC module over AES. I’ve attached a block diagram & it’s clear to see.

 

You might also try your CD out via optical to the Makua DIGIN Toslink input - without the Mu-1 intermediate upsampler of course so maybe not as good though it is one less component (I’ve not tried this as I only use my CD player analogue outputs as I mainly use it for its SACD stream direct to a dedicated Makua analogue in)

[dctom]

I like your diagram very informative. I have tried the CD directly into the Makua and unsurprisingly it is better than through the CD's DAC but not as good as through the MU1.

Trying to work out how to get my computer server to play through the Grimm now.