Grimm Audio MU1 and MU2 Music Players

[SackATK]

My previous digital setup included a USB chain consisting of a Sonore opticalRendu streamer, Uptone Audio ISO Regen USB reclocker, and Innuos PhoenixUSB reclocker.  It utilized some very good USB cables and DC cables with some very nice low noise linear regulators cleaning up the DC power from an HD Plex 300W LPS. This setup sounded great!  At the time, it was the best I had ever heard.  I could've easily stopped there and just enjoy. The only downside was the number of boxes and cables and determining how to place everything. 

 

The Innuos PhoenixUSB was a transformational addition to the system and it provided a good lesson. This USB reclocker has an excellent clock and power supply built into the unit.  The clock and the DC power are very close to the parts that need them.  These design decisions allow it to perform at a level above other implementations.  Of course, the same design decisions can be said of the MU1. 

 

So a few weeks back I decided to try the MU1 because it would accomplish a few things for me.  It can replace most of the boxes and cables, it would satisfy a small curiosity with upsampling, and it would allow me to reclock spdif for a few components that output spdif.

 

Initially a Sonore opticalModule fed the ethernet signal to the MU1 using a no name ethernet cable and a Grimm TPR AES cable was used on the output. This combination bested my previous USB chain.  I didn't take notes but I remember their being more low level details and I believe tonality was more correct and everything else was better except for perhaps dynamics.  Now when I did this comparison, the MU1 and the TPR cable were still fairly new and the state of burn in was unknown. 

 

I sold most of my USB chain and I've been happily listening and tinkering with ancillary cables and components. The Grimm TPR cable was replaced with a Shunyata Alpha AES cable and this was an improvement.  Then the Shunyata Alpha AES cable was replaced with a Shunyata Omega AES cable. This was not a subtle change.  Many things improved and there was a noticeable drop in the noise level.  Then I implemented Supra ethernet cables into the system, removed the opticalModule, and most importantly, I added an Innuos PhoenixNet switch between the router and the MU1 and "astounded" is the word I want to use.  With the PhoenixNet, sounds became more well formed and the pieces in the soundstage had more clarity. Transparency was better and the "pops" popped more, if you know what I mean. Each percussive sound felt like a punch in the face/ear drums.  The bass performance was nothing like I've ever experienced in my system.  It almost felt like there was too much super tight dynamic bass... but I'm not complaining. My research indicated the PhoenixNet would benefit the system but to experience the ways the music has improved is something else. I solely stream music with the MU1 so I don't know how playing music internally stored in the MU1 would compare.

 

The MU1 was used to supply the digital signal to Kii Three active speakers and to a Benchmark DAC3/HPA4 headphone stack.  Power conditioning and cables are higher end Shunyata Research. 

[SackATK]

I don't know if this is really new info, but a few days ago, I noticed this on the Grimm Audio website under the MU1 webpage: "Spotify and Tidal Connect support (soon)".  I'm eager to do Tidal Connect on the MU1 because I use Tidal Connect more than Roon day to day and this would allow me to eliminate the Bluesound Node 2i from the system because it's main purpose is to utilize Tidal Connect.  And my spdif implementation out of the Node 2i (also connected to the PhoenixNet) doesn't sound as good as Roon directly on the MU1. 

[SackATK]

On 5/5/2021 at 6:52 AM, Kenkuan said:

I was told MU2 could be one year away, if you can wait😅

 

I couldn't... Now waiting for delivery of MU1. 

 

I have lofty expectations of the MU2.  It would make me a very happy man if it can beat my headphone DAC because it would allow me to free up a very expensive AES cable and power cable.  Simpler is better in my book. 

[SackATK]

14 hours ago, FredM said:

Congrats SackATK. Thanks for sharing! Nice decluttering 👍, combined with active speaker systems the MU1 is a great and simple front end solution/hub.

Thanks Fred!  I haven't tried many combinations of speakers and front ends, but the MU1 and active speakers is an excellent combo for sound and simplicity and simplicity for me allows for more bang for the buck.  I also thank you for starting this thread because it's one of the key reasons why I'm currently enjoying the MU1. 

[SackATK]

12 hours ago, FredM said:

I personally wouldn’t judge (pun intended 😁) a device on its specs. In a specs first world it would be better if the Dave would support the full AES/EBU spec. With the AES input at 96kHz max it could impact SQ, but who knows? And if, even a ‘95% ideal spec first performance’ could still be well preferred sound wise.

 

Besides the AES/EBU output, did you know that the MU1 now also has a S/PDIF digital out? Perhaps this is useful in your situation. Link to announcement 

 

I would just to ask for a demo. Trying one of the above mentioned options you know much more. If you like it SQ wise, you could swiftly enjoy your music and already sell 3 boxes. When a MU1 is upgradable to a MU2 (ask a dealer), you decide later if it will also replace the Dave. I don’t know a lot other one box solutions on the market which offer a Roon server, clock, upsampler, endpoint and DAC as an alternative. And of course, if you don’t like the MU1 at first you know you can look elsewhere. Imho a ‘best’ doesn’t exist, it about personal preference and synergy with other gear and room.

Great point on the dedicated spdif output. I ordered my MU1 mid March and it came with this new output.  However, I believe the firmware that would enable this output is forthcoming.    This feature should be enabled in the next firmware update and I'm hoping it will also include support for Tidal Connect. 

[SackATK]

That's a very positive review of the MU1.  I also considered the Antipodes K30/K50 for my next streamer and this review makes me feel great for choosing the MU1.

 

Like the reviewer, I found Roon bested the other digital inputs.  And it's interesting to me that the reviewer never mentioned the type of ethernet cable(s) used and whether or not there was an audiophile switch upstream of the MU1.  One of the pictures had what looked to be a standard ethernet cable hooked up to the ethernet input.  The reviewer mentioned that a transport when done right can have more "depth and flow" than the MU1.  I wonder if he were using say a PhoenixNET switch with high end ethernet cables if he would think differently.  In my experience, the PhoenixNET switch with entry level audiophile ethernet cables made Roon playback sound like it was done on a "MU1+". 

[SackATK]

On 7/18/2021 at 6:19 AM, TheAttorney said:

My MU1 goes AES direct to a DAVE DAC/headphone amp.

 

But I think it's an oversimplification to imply that PhoenixNet or Sablon are the only things that have great synergy with the MU1.

For example, a while back someone raved over the Shunyata Omega AES cable. I would have liked to try that one, but its price was way more than I'm prepared to pay for a single cable.

 

From what I've learned so far, the MU1 is affected by much the same surrounding components as any another digital device I've come across. I had wished it wasn't so. Because the MU1 had successfully isolated the noise created by Roon, I did wonder whether it could also isolate the noise from the mains supply etc. It would have saved me much money if I could have connected stock everything to the MU1.

 

But I'm not complaining - making Roon sound so good is a big step further than just about any other manufacturer has managed to achieve (I don't think the $25k Extreme would be a fair comparison here).

 

 

 

TheAttorney, I enjoy your posts and learning of your experiences with the MU1 and associated tweaks.  I too wished the MU1 was immmune to its surroundings but my own experimentation proves to me this is not so.  

 

Grimm Audio has done such a wonderful job of designing what happens inside the golden dome black box. They put a lot of effort into the AES output and it would be less than ideal to limit this in any way with any ho hum AES cable. I decided to bypass the upgrade game and go straight to what I thought was the best AES cable I can get and that was the Shunyata Omega.  Other cables may be good enough, but that's for each listener to try and decide.

 

For your next tweak, I would highly recommend a very good network switch designed for audio.  I have the PhoenixNET but less pricey ones may be good enough. I don't know because the PhoenixNET is the only swich I've ever used. Again, I went straight to what I thought was best. I want to share this experiment I did just minutes ago. The well regarded ENO ethernet cable and ethernet filter connects the MU1 to the PhoenixNET.  I turned off the MU1 and disconnected the ENO system from the PhoenixNET and inserted it directly into the router, thus bypassing the PhoenixNET.  I turned back on the MU1 and had a listen on the Kii Threes.  The music got smaller as if it was put into a box. It lost some magic and fun.  Many good musical attributes went downhill.  This was remedied when I reverted the network changes. You don't know what you have until it's gone. In my music system that is designed to reduce all kinds of noise, the PhoenixNET was a major upgrade and for me the network switch is a necessity for maximum performance.  With the MU1 and the tweaks I've done directly before it and after it, I've surprised myself at where I am on my audio journey.  I know I can improve the system further but I would not mind staying put for a very long time. 

[SackATK]

I should mention both the MU1 and PhoenixNET are powered by Shunyata V14 Digital power cables.  The modem and router are powered by an HDPlex 300W LPS that is itself powered by a Shunyata Delta V2 NR and everything AC is connected to a Shunyata Everest power distributor. 

[SackATK]

Does the MU1 need fancy cables to do its magic? No. Can it be improved with fancy cables? Yes.  In my experience, the responses above is universal to all audio components I've had the pleasure of owning or demoing.  I've played with two ethernet cables and three network switches with the MU1. These things made an audible difference in my system. I've yet to switch out the Shunyata V14 Digital power cable but I would expect a fancier cable to sound better.

[SackATK]

46 minutes ago, aangen said:

I think it s common for gear manufacturers to say you don’t need nor will you benefit from expensive cables. Lots of people agree with this. Many of us believe otherwise.

 

I'm in the otherwise camp.  And to prove that they matter, I use the best measurement tools I have called my ears and my brain.  Both have evolved over many millenia and the latter is the best supercomputer ever known.  At the end of the day, I have to make myself happy and not some oscilloscope. 

 

I don't blame manufacturers for saying cables don't matter. They spend all of their time and research to make their products work well (as they should) and these are things they can control (things internal to their products). They can't control external factors like what cables listeners decide to use with their products so why spend precious energy to determine rigorously how cables impact their products?  And no manufacturer wants to say to a customer you're missing out on 30% better performance for the DAC if you don't pair it with a $2000 power cable. 

[SackATK]

My favorite quote from the video:

 

"I have a problem here, for I'm not sure I'm able to fully describe what I'm hearing..."

 

Some of us understand this fully.

 

I'm excited about the new features coming down the pipe as well.  My Benchmark DAC3 I believe has the 3dB Headroom feature built in but now it seems like all DACs can possibly benefit from this feature with the MU1.  Very nice. 

 

 

[SackATK]

After firmware update, go to Menu [4/7] and there is the IP address and a QR code for the web interface. 

[SackATK]

Link to Grimm Audio press release for the v1.4.0 firmware update:

 

Link

 

And the firmware v1.4.0 change log:

 

Link

 

I had a listen last night and I thought I heard better resolution.  But it's hard to know for sure because recent system upgrades have been very good in this area.  This was before I read that there should be sound quality improvements with the firmware. Love free upgrades. 

[SackATK]

As an experiment, I just recently successfully configured my system to be MU1 endpoint only, utilizing a roon server on an external NUC I still had laying around. I will leave it in this configuration for a while to get use to the sound but I can say there is no dropoff in sound quality. If anything, there might an uptick in quality.  I will know for sure after I revert back to server in MU1 and retesting. 

 

In this new configuration, I've lost album and track info on the MU1 display but for me this is a minor inconvenience.

[SackATK]

Yes, that's essentially what I did to get the MU1 to work as endpoint only.  I would add reboot the MU1 after logging out of it's roon core and then unpause it after it comes back up.  Now it should be ready for play.

 

Over a year ago a lightning strike sent a power surge through the internet coaxial cable and ethernet cables. This damaged my cable modem, router, and my Logitech Touch that was serving as an expensive digital time piece.  Fortunately, the rest of my system was isolated from the surge and no further damage was done.  I mention this because the MU1 is a pricey device to replace so steps should be taken to protect it from this type of surge. 

 

After this power incident, I bought a mesh router system that came with three wireless routers. The main router is connected to the cable modem with an ethernet cable and wirelessly serves the other routers.  I put a surge protector on the coaxial cable feeding the modem but if this fails to protect, only the modem and this main router will be damaged.  One of the secondary routers serves the MU1.  In-between this router and the MU1 is an Ediscreation Fiber Box II and a Paul Pang Quad Switch.  When connecting the NUC, I could've connected it to the switch but the mesh router had a spare ethernet port and I chose to connect it there. The idea here is to take advantage of the galvanic isolation offered by the Fiber Box II. 

[SackATK]

Below is a link to the surge protector I use.  In my experience, it does not reduce my internet speed.

 

 https://www.parts-express.com/Cable-TV-In-Line-Coaxial-Surge-Protector-180-190