Grimm Audio MU1 and MU2 Music Players

[PYP]

59 minutes ago, Mike123 said:

My dealer agreed to send Mu1 for 14 day demo. Im moving off Innuos MK3 and their PhoenixNet + USB reclocker to DAVE/HMS which Ive been told was as close to Statement as you can get (sans the sean jacobs PS) 

Question ....what's the burn in time and experience for MU1. With a superior BNC cable , hoping to get that component level jaw dropping experience? Is that a reasonable expectation?

Just one person's two cents:  If the unit has already been broken in for two weeks before you get it, you will most likely hear its potential over a 14-day demo.  IIRC, mine took a month to break in and improved in small ways for another month or so.  Of course, I heard positive qualities before one month.  

 

The BNC does make a difference, so if you have a good cable that is broken in that will be a plus.  I tried Mogami cable, which wasn't bad at all, but more can be had with other cables, depending upon your preferences.  

 

Personally, I like to go into a demo with as few expectations as possible.   

 

Have fun!

[Mike123]

thanks for that -- shaping it all down to one box while improving SQ would be ideal. Wondering if i should hold onto the USB reclocker even though Grimm recommends the AES

[soupcon]

1 hour ago, Mike123 said:

thanks for that -- shaping it all down to one box while improving SQ would be ideal. Wondering if i should hold onto the USB reclocker even though Grimm recommends the AES

I would go with AES or spdif. I have a canare DA206 and a Grimm TPR if you want to borrow them to try. That said, I wouldn’t hesitate to invest in a higher end cable, depending on what your tastes are. 
eager to hear about what you hear with the mu1. (I am totally in love with mine)

[Mike123]

thanks for the feedback! considering the Sablon AES. Not in the Shunyata realm, but Ive heard it provides great SQ for the money. 

[PYP]

1 hour ago, Mike123 said:

thanks for the feedback! considering the Sablon AES. Not in the Shunyata realm, but Ive heard it provides great SQ for the money. 

Your audio dealer might have a cable for the demo period.  

[aangen]

I use a Stealth Audio AES/EBU cable to my Gryphon Ethos. It seems to do zero damage to the signal. AES is the right cable.

[TheAttorney]

19 hours ago, Mike123 said:

With a superior BNC cable , hoping to get that component level jaw dropping experience? Is that a reasonable expectation?

If you've read my earlier posts on my MU1/DAVE journey, you'll not be surprised to hear that my recommendation is that you ditch the HMS, as IMO, the MU1 makes it redundant. In which case, there's little point in pursuing BNC cables. Demo with the best AES cable you can get hold of - which really simplifies the cable situation, and you can get some money back by part exchanging, or selling, the HMS.

 

I rarely have a jaw dropping experience if I'm expecting to have one. I agree with the suggestion that it's best to approach the demo with no particular expectations.

 

I can't remember the burn-in time, but I do think that several hours warm-up time (suggest 8+) gets the best out of the MU1 (as it does for most components).

[PYP]

I agree with the AES recommendation and use AES myself.  For the demo, I would pass on the recommendation given me:  leave the Grimm on during the entire time (I still do that).    

[pvanosta]

11 minutes ago, PYP said:

I agree with the AES recommendation and use AES myself.  For the demo, I would pass on the recommendation given me:  leave the Grimm on during the entire time (I still do that).    

+1 on that. My MU1 (and my Grimm active speaker/subwoofer set) remain on 24/7.

[Mike123]

1 hour ago, TheAttorney said:

If you've read my earlier posts on my MU1/DAVE journey, you'll not be surprised to hear that my recommendation is that you ditch the HMS, as IMO, the MU1 makes it redundant. In which case, there's little point in pursuing BNC cables. Demo with the best AES cable you can get hold of - which really simplifies the cable situation, and you can get some money back by part exchanging, or selling, the HMS.

 

I rarely have a jaw dropping experience if I'm expecting to have one. I agree with the suggestion that it's best to approach the demo with no particular expectations.

 

I can't remember the burn-in time, but I do think that several hours warm-up time (suggest 8+) gets the best out of the MU1 (as it does for most components).

Correct, I meant to say AES. BTW, truly appreciate your detailed comments in transitioning from DAVE/HMS. As a matter of fact it was your experience and Hans Beekhuyzen's that convinced me to at least trial the Mu1.

 

[George Hincapie]

On 4/28/2020 at 9:17 PM, FredM said:

Here you go, please let me share my journey/ process to decide for the MU1. In a follow up post I’ll attempt to describe the music experience with the MU1. Besides getting more familiarised with the MU1 at first, hopefully my enthusiasm is settled down (and my night sleep is also back to normal by then). Hopefully I’ve also thought of one simple word to describe the MU1, it isn’t only the qualities, there is more, hard to grab. 

 

As some of you might know, my quest for a decent digital front end started a while ago, to be combined with Harbeth speakers, Primaluna Dialogue amp, Metrum DAC in a medium sized room with some acoustic treatments. A joyful system, and very much to my liking. As part of my interest/this hobby I tracked the latest and rapidly changing front end developments. With Linn’s mantra ‘source first’ in my head, I decided the source should be the cherry on top.

 

As several source (related) products where launched: server, endpoint, OS, clock, switch, psu’s and cabling, eventually I preferred an one-box-solution. Having no technical knowledge or relevant DIY skills to build something myself, I reckon it would be difficult and time consuming to determine a good mix of devices/cabling/.. Most would become trail and error in my case. With already some devices in and on the hifi cabinet, I also wanted to avoid a plethora of source related devices/cables.

 

There where not that many servers on the market to my liking. When the hifi tailored AudioLinux software got more traction. I was eying a particular server with this kind of software onboard. Long story short: this appeared to be a dead end street, with a year waisted. Meanwhile -on the opposite side of the system- the idea of an active speaker system was growing on me. Similar to a one box source, an active speaker system is designed and tuned as one. The Grimm LS1, Dutch & Dutch 8c’s and Kii Three would be the usual suspects.

 

When hearing the D&D and Kii Three for the first time I was surprised with their performance. Later I listened at the Grimm LS1 at a Dutch audio show (XFI 2019), their statement LS1be speaker system was connected with the MU1. What an experience, like a goosebumps inductor, once 3 times during one song..! This really grabbed me. Of course I haven’t listened at all speakers in the world, although more than enough to know this was very special. A fair amount of the afternoon I just sat in the room enjoying song after song. I remember driving back home, ‘I’ve just found a gem’.

 

A while later at a dealer I had a direct comparison with the D&D 8c and two LS1 models from Grimm. The D&D and Grimm are both stunning speakers. I favoured the Grimm LS1a, where the LS1be with the dmf subwoofers in my experience where just magical. I was in love. Unexpectedly I was able to go ‘all in’ and sold my complete system and bought the LS1be’s. As much I liked my previous system, I never looked back. The LS1’s simply play in another league.

 

Regarding the source I still was at square one. Oddly the MU1 wasn’t on my radar at first. In fast forward I went thru a similar thought process as before, pondering about separates vs an one-box-solution. I even thought of building my own server. I did some research on fanless cases, motherboards, RAM, cabling, psu, internal cards/bridge, etc. Where I have utmost respect for those who are skilled and have the time to discover and create servers themselves and share their insights online (which I enjoy reading, many thanks @seeteeyou, @austinpop, @bobfa, @romaz, @Nenon and many more!), I reckoned a turnkey solution would be more appropriate for me. 

 

As the MU1 was well received in the Dutch hifi press I realised the answer could be right under my nose, with the additional advantage that speaker and source will match excellent. Then, the more I read about the MU1, the more fascinated I got, hence this topic. Not looking on Grimm MU1’s sound quality, there are some other aspects which I find appealing and are perhaps worth mentioning:

• The design approach, as first mentioned in the OP the importance of matching the format of the source with the ‘native’ format of the DAC. Also walk the talk by choosing for S/PDIF via AES/EBU as the single digital output which carries the clock (quite daring as USB is most commonly used for consumer products).
• Custom end-2-end design and build, only the NUC and (optional) SSD are of the shelve components. i.e. the psu of the MU1 is developed by jitter measuring at the clock. Track record developing oscillators (Guido Tent, Tentlabs), like a server build by jitter experts.
• Deep understanding how ‘music works’, with Eelco Grimm being a front runner for Loudness Normalisation (ie analysing more then 4 million albums on Loudness, which recommendations are implemented by Tidal)
• As with other Grimm products, the MU1 isn’t just buying a server/streamer. Upgrade possibilities will appear, making the MU1 a future proof investment. Sure it’s a lot of money, but with good value imho. The MU2 is already announced (MU1 with internal DAC). Grimm is also working on custom playback software, as a free alternative for Roon which will deliver a higher sound quality.
• It took the Grimm team of experts (with Eelco and Guido also being university lecturers) about 4-5 years to develop the MU1. No way I will be able to match that with source (related) devices, where I mix and match products myself.

 

So far my personal ‘journey post’, I hope it was interesting and perhaps useful for some. As I’ve enjoyed reading about the process and discoveries of others online, nice to share something in return. 

 

 

 

Oh, @beautiful music, here’s a nice picture, as requested 😋

 

So no more Metrum in your life Fred? That's sad 😭

[pvanosta]

I can echo Fred’s journey with my own. I have had a case of audiophilia nervosa for the best part of 40 years, leading to buy, trade, switch out equipment from Nakamichi, Thorens and ESS via Martin Logan, Classe, Thiel, Marten, Hegel, Auralic, Devialet, Perreaux, Bel Canto, etc etc. Then I heard Grimm LS1be at a Dutch audio event and that was that. I looked for a used pair to hit the market and sold my Devialet 440 and Marten Django. Next step was the MU1 and now I am 99% done. If I can find one last upgrade from LS1 to LS1be, I am all set. Even my issues of Stereophile and Absolute Sound are sitting unread on my IPad for the first time in decades…

[skyline]

18 hours ago, pvanosta said:

Next step was the MU1 and now I am 99% done. If I can find one last upgrade from LS1 to LS1be, I am all set. Even my issues of Stereophile and Absolute Sound are sitting unread on my IPad for the first time in decades…

 

It's never done 😀

 

You will eventually find something else that blows the doors off your expectations.

 

And those are lovely moments in this hobby.

[FredM]

On 8/27/2022 at 3:12 AM, George Hincapie said:

 

So no more Metrum in your life Fred? That's sad 😭

Hi George, nice to hear from you again 👍. I still very much like Metrum DAC’s, as separates they offer great quality and sound. I indeed went all-in for an integrated active speaker system where speakers, amps and DAC’s are tuned as one. Just love it, since I uses the Grimm’s I haven’t looked at other speakers, DAC’s etc once. No itch, just enjoy the music 😀

 

For people with a ‘traditional’ setup (speaker and amp), I wonder when the Grimm MU2 appears on the horizon. With Core, PSU, Endpoint, Reclocker/Scaler ánd DAC inside a single box, is could be an appealing product for those who want high performance and small footprint (declutter ambitions). I’m most curious how the MU2 would perform against separates in the same range. When it has a comparable effect as the integrated speakers (synergy, designed an tuned as one, etc), Grimm could have something special. But hey.. it’s not on the market yet, so who knows. 

 

Perhaps more news on the MU2 will be released during the Dutch Audio Event (8-9 Oct). I’m aiming to go on Sunday.

[soupcon]

On 8/18/2022 at 10:19 AM, Mike123 said:

My dealer agreed to send Mu1 for 14 day demo. Im moving off Innuos MK3 and their PhoenixNet + USB reclocker to DAVE/HMS which Ive been told was as close to Statement as you can get (sans the sean jacobs PS) 

Question ....what's the burn in time and experience for MU1. With a superior BNC cable , hoping to get that component level jaw dropping experience? Is that a reasonable expectation?

 

did you get to try the MU1 yet?

[Mike123]

On 6/24/2021 at 2:28 AM, TheAttorney said:

My MU1 impressions - Round 2.

 

The MU1 on home trial replaced my existing components as follows:

 

     SR7 p/s with 3 DC cables powering: NUC > USB cable > IsoRegen > USB cable > M-scaler > 2 x BNC cables > DAVE

was replaced with:

     MU1 > AES cable > DAVE

 

Both MU1 and M-Scaler were set to their maximum upscaling (4FS and 16FS respectively) as this sounded best in both cases.

 

As start point, I was feeling pretty good about my NUC-based system. Although many here at AS have gone much further than I at optimising their NUCs, I still felt I had a high performing system, with the excellent Euphony Stylus carefully tweaked to give a well balanced sound with no obvious downsides. And the superb Mundorf gold/sliver DC, Sablon 2020 USB and Vertere Pulse HB BNC cables all being "end game" cables IMO that significantly lifted overall performance.

 

However, much of the NUC was still stock, such as the USB output coming straight off the board, so I knew that further improvement was possible. So on balance, I had no idea how this test would go. The worst possible outcome would be that MU1 sounded a bit better, but that I had to strain to hear the difference. In which case, I would be in a dilemma between my downsizing objective vs only minimal SQ improvement for the high cost of change.

 

As it turns out, it took only seconds of the first track to realize that the MU1 was performing in a higher division. To sum it up in a single phrase, I would say that "the MU1 is an open window into the recording studio". Every tiny detail, at any frequency, was presented untarnished and without smearing. I was having to re-appraise albums that I thought I knew well. The most worthwhile change was for my "ok" albums (ones that were fairly good but unremarkable) - these could take on a new lease of life. Audiophile recordings also improved, but these had previously sounded great anyway. No recording ever got worse, but some changed character as the "open window" exposed every characteristic of that recording.

 

There are some caveats:

 

1. The above WOW effect occurred with the dealer-supplied Audioquest Diamond AES cable (around £900). The SQ went down significantly (softer with loss of fine detail) when I tried the AES>BNC converter cable. My understanding was that this was supplied by Grimm, but the wire was by Belden, with Neutrik XLR plug at one end and Canare RCA plug at other end, onto which was a hard RCA>BNC converter.

From my spares box I had some sensible, no-nonsense "pro" microphone XLR cables (in the £20-£40 range). The Van Damme sounded slightly better than  the Belden, and the Sommer Carbokab 225 sounded quite a bit better than the Van Damme, but not as good as the AQ. So the AES cable is critical to get the best out of the MU1 and I'm undecided what to do about it. Sticking with the Sommer for the moment.

 

2: I tried Roon's DSP for PEQ and cross-feed and this was an obvious step down from bit-perfect (as it has been every time I've tried Roon's DSP in the past). So MU1's magic does not extend to Roon's internal DSP algorithms, which is a great shame, but not surprising.

 

3. I felt that MU1's "gold disc" volume control slightly reduced transparency (compared to leaving it at 0dB and solely using Dave's volume control). This was subtle and requires further tests to be conclusive.

 

That's all for now folks. In Round 3, I'll comment on MU1's look&feel and practicalities.

PS. I did buy the MU1 🙂

 

 

 

Again, this is by far the best lab A/B test on the MU1 I've read so far  -well done, Attorney. My Mu1 will be arriving tomorrow for a 14 trial.  A  Shunyata AES cable is on its heels the following week. Really curious if I'll have the same "chicken skin" experience when removing the Innuos USB reclocker from the chain and connecting directly to the DAVE. If all works out and Im able to recoup from selling HMS, Innuos MK3 streamer and, USB reclocker (along with Wave Storm BNC and Shunyata USB cables) I'll come out ahead by $75 and have some real estate in the cabinet! (ugh likely for a future hologram streamer in 2025 -it never ends!) for I'm on the road now and will plug n' play on Monday! 

[Mike123]

On 7/11/2021 at 5:50 AM, TheAttorney said:

My MU1 impressions - Round 3. Look&feel and practicalities.

 

The MU1 in real life looks just like I expected from the photos.

It doesn't scream heavy weight "high end" extravagance. It's more about simple, restrained elegance.

Grimm wisely chose well to give the gold disc a very matt finish so it doesn't look too blingey against the matt black enclosure.

That restrained gold disc helps give a Japanese Zen-like vibe to the minimalist enclosure. With the display switched off in standby mode and cables hidden round the back, the MU1 doesn't even look much like a hifi component - which resulted in an unexpectedly high WAF rating from my wife.

 

The display is clear and unexpectedly useful. It's great to use Roon's "music magazine" UI for discovery etc, but sometimes I want to just listen to music, and for those times I queue up a couple of albums, enable roon-radio, and then close my control laptop. The MU1 display shows, amongst other things, the artist/album/track/progress and one can pause/restart by pressing the gold disc. Even better would be if one could skip track forward and back - I understand this feature will come with the IR Remote Control functionality due in the next firmware release (due around August).

 

My downsizing objective insists that networking is via WiFi (direct to my broadband router in another room), so I don't have to bother with long ethernet cables, super switches, super clocks, super power supplies etc etc. The tiny Wifi dongle recommended by Grimm (TP-link WR802N) is matcbbox sized and works better than I could have hoped for: it's powered by one of MU1's USB ports, with the supplied ethernet cable plugged into the ethernet socket. It consumes less than 0.5W power and automatically comes off and on when MU1 is put in/out of standby. But best of all, I can barely tell the difference in SQ (when playng local music files) whether or not this dongle is active - not bad for £26 including the skinny USB and ethernet cables. There could be some wishful thinking clouding my judgement here. In a future firmware release (after remote control), Grimm are aiming to provide USB-only WiFi support, at which point I will be able to try an even simpler WiFi solution.

 

The MU1 consumes about 17W AC power when playing music (no DSP), which drops slightly to 16W when music stops.

And drops to just under 5W in standby mode. Before removing the power cord, the instructions are to press a tiny button round the back. This definitely does something because the LED light goes out, but interestingly the power consumption stays at 5W, so I'm guessing that this micro switch isolates a particularly sensitive bit of circuitry, without fully switching off the whole unit, which leads me onto the fuse....

 

The back fuse drawer contains 2 fuses (630mA and, unusually for AC, rated as FAST BLOW). The first one you come to is a spare. All this is important because I've confirmed to myself that the fuse does impact SQ (I'm a committed fuse-o-phile, so this should be no surprise). More about that on my 4th and final round about cables and tweaking.

 

Any downsides?

 

Not much. I find the LED light, even at its lowest setting, too bright for night-time listening. Grimm told me it can't be set any lower with current hardware, so this won't  be changed any time soon. I've carefully dabbed the tip of the LED with a black marker pen and this helps tone down the brightness.

 

The main display is also too bright for my liking (to be fair, most manufacturers' LED/displays are too bright for me). Grimm are aiming to add some adjustment for this at a future firmware release (after the remote control one).

 

In short, I'm very happy with my MU1 🙂.

 

On 7/11/2021 at 5:50 AM, TheAttorney said:

Received my Mu1 today and was curious how you are using the single AES cable in relation to the DAVE. Are you using one of the two "OUT" or the single "IN"? thanks again 

 

[TheAttorney]

14 hours ago, Mike123 said:

Received my Mu1 today and was curious how you are using the single AES cable in relation to the DAVE. Are you using one of the two "OUT" or the single "IN"? thanks again 

It has to be one of the two OUTPUT AES sockets for DAVE.

The INPUT socket is for other source components, such as a CD transport.

 

Either of the OUTPUT sockets will be fine. They are each separately configurable for a couple of things such as volume control. I found it best to switch off the volume control feature (leave fixed at 0.0db) and use DAVE's volume control.

[Mike123]

Excellent thank you!

[Mike123]

On 8/31/2022 at 9:44 PM, soupcon said:

 

did you get to try the MU1 yet?

On Day 2! I went for broke (literally) and bough the Shunyata Omega AES cable. A backdrop on my music preference: As an alleged drummer, I listen to musician performance content with no vocals.  As such, rapid moving transient percussive sounds are ever present including congas, timbales, trap sets, both in-studio with close and overhead mic'ed drums and bongos. A chief frustration in other stereo rigs was that the bass guitar (especially acoustic) would invariably compete in the 18-22khz range with the bass drum. They'd essentially cancel the other out with in-deciphering rumbling and booming low end. Initially I was going to replace my B&W 803D3 speakers , then decided to explore other components. In came Innuos' MKIII streamer with DAVE and MScaler in the chain. Cables were Wave Storm's BNC connector and Ferrum Sypsos Power supply for the MScaler. This setup helped, however not 100%. Still getting fatigue in low end. 

Then I read The Attourney's post along with watching Hans Beekhussen's youtube. Hans is alot like me. He has budgetary constraints and will not exceed them unless something legendary comes along. It did. the Mu1. What got me was that Hans had highly praised Chord Electronic's MSCALER to the point that it was irreplaceable and a constant companion to the DAVE DAC. The Mu1 replaced it.  

Well , let me tell you that the boominess is completely gone! The music is unbelievably emotional and immersive. Each instrument- percussive and otherwise  has its intended assigned and mixed location in the sound stage. Im no longer a consumer evaluating and justifying a $10,000 purchase. I'm where I want to be - appreciative of musicians at the top of their game. And it's only going to sound better..

[Mike123]

I do have another question -- how do you know the storage capacity of the internal SSD? 

Mine is 8TB, but I cant confirm

[soupcon]

@TheAttorneyare you still using the TP link box to connect to the network?

 

@Mike123not at all surprised by your mu1  “skin effect.” 😀

[TheAttorney]

12 hours ago, Mike123 said:

I do have another question -- how do you know the storage capacity of the internal SSD?

I don't know how to measure this. The best I've been able to measure is how much space is used by the music folder on the SSD (by viewing the MU1 as a networked drive on my Windows laptop. This also shows the full folder structure on the SSD.

 

Anyway, I'm relieved that you've had a good result - one can never be sure how anyone else will react to the same equipment.

 

11 hours ago, soupcon said:

@TheAttorneyare you still using the TP link box to connect to the network?

 

Yes. and it remains my most pleasant surprise in my recent hifi journey.

 

For completeness of information:

 

From my spares box, I added an ifi silencer+ USB noise reducer dongle between the TPLink and MU1's USB socket. And 3M's EMI-reducing sheet loosely placed between the TPlink and the cables of my hifi system. This was a belt and braces approach to noise reduction made easy because I had these components spare. But I can't say I noticed any difference in SQ when I added them. Again, if I can't tell the SQ difference whether the TPlink is plugged in or not, it doesn't seem worth spending too much time trying to tweak it or look for better solutions.

 

My broadband/wifi router is on the far side of an adjacent room, so the wifi signal from that is not too strong. The result may have been different if that router was in the same room with a strong wifi signal.

[Mike123]

2nd week with MU1-- still a tad bright with Shunyata AES cable but not as shrill from first few days. However, like most, I'm re-evaluating songs I thought I knew well! 

 

Question, not able to play local files through Roon. Open to suggestions on creating Roon file path for both NAS and locally stored? 

thanks so much 

 

Mike

[The Computer Audiophile]

The MU1 arrives here any day :~)