Grimm MU1 - demo impressions
Jan 1, 2021 at 1:46 PM Thread Starter Post #1 of 49

bluecar

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So, Steve at Ultimate Stream very kindly lent me a Grimm MU1 to demo over the New Year....I've been looking for a server, and to upgrade my bridge for a while, so this seemed a good opportunity to look at the heavy-caliber end of the offerings on the market....This is not a review, just my impressions - there are plenty of pro reviews out there for this unit.

The MU1 is a Roon Core and a Roon client, embedded in some proprietary Grimm Audio tech, mainly power supply and output boards. It functions very well as a Roon core/player and that's mainly how I've been using it. Roon is the only choice at the moment, although Grimm are planning to bake in their own system soon. The unit is incredibly well made, and carefully finished. The 'mushroom' controller on top is a thing of beauty, but I confess to having touched it once in 3 days - all control is done via the iPad.

The setup is.....

Grim Audio MU1, (connected to network via AudioQuest Vodka ethernet and Fidelizer Etherstream switch)
Chord DAVE (connected with Audioquest Diamond AES/EBU)
Benchmark HPA-4 (connected via Chord Signature XLR to DAVE)
Focal Utopia (connected to HPA with Forza Noirt Hybrid balanced)

All the kit is mine except the Grimm and the Audiouest AES/EBU, (kindly loaned by Steve) - the AQ diamond is lovely, very well-made, extremely high quality and (£1200!!!! to buy). I may look for less costly options if I go down the AES route :D All power delivered by MCRU No75 power cables.

The Dave-Benchmark-Focal combo is brutally revealing, so an interesting test of the Grimm's impact as a source. I usually stream from a NAS into a Sonore MicroRendu (with LPSU) - I'm not going to contrast to that, as it's pretty unfair comparing a $1000 streaming combo with a $13,000 server/streamer!! Rather, I wanted to test the various options available to me through the Grimm.

First up, it's worth noting that the Grimm only has one output option - AES/EBU. They put a ton of effort into the output stage, including some exotic clocking technology, so didn't feel the need to bypass that with USB. You are left with two choices....a) use Roon to upscale (or not) and pass it to the DAC or b) let the MU1 do the upscaling and leave Roon upscaling off.

So I tested it with pass-through and upscaling, and also did some comparisons between local storage in the Grimm, My NAS and Qobuz...

So, first decision - let the Grimm handle the upscaling. In every album I listened to, the sound was more resolved, more detailed and more enjoyable using the Grimm's scaler - more refined, more musical, more heft, better low registers....I could go on. Whatever Grimm did in this circuit, it's profoundly better than anything I can achieve in software via Roon or HQP....so I left it set to that and moved on :D

In terms fo Nas vs Local, local wins by a long way. Texture is better, detail is better, musicality is better. Again, I don't know the technical details, but the act of playing the exact same rip form the local drive is much more resolved than playing it from the NAS store.

Streaming from Qobuz was interesting. testing with albums I have on my server, internet streaming was a little less resolved than playing the file from within the Grimm, but not by much.

In my preferred config, the Grimm was pulling up musical detail I'd not heard before, from rips I've been listening to for years. On Pink Floyd's "Wish you were here", there's a beautiful slide guitar melody filling in the right, which I'd always been aware of, but never could hear distinctly from the synth tracks - with the Grimm it is clear, separate and rich, adding another layer to the overall sweetness of the track. In "So What" by Miles Davis, the walking bass is harmonic and rich via the Grimm, and the percussion snaps and glides with the melody in a much more integrated way. On "The Man who sold the world" there's a ton of bass harmonics on "Width of a Circle", that were never really clear before, and ass the bass is center-mix and quite prominent, add a lot to the texture and rhythm of the track. It was much the same on all the tracks I compared - more detail, more music, more emotional enjoyment.

It's a strange experience, and not immediately obvious, but playing from the Grimm disk, and via the hardware scaler, instrument definition is exceptional - backing tracks resolve into multiple singers, guitar chords ring true and complex mixes are opened up and laid out for listening. But all of that with musicality and coherence. There is no 'edgy' edges on guitars, vocals, or percussion unless the original recording meant there to be. At no point did I ever feel I was missing out, with the Grimm being sample-rate-capped by the AES connection.

Overall, changing source and server stepped up the enjoyment of music for me. I've demoed lots of high-end kit, but few delivered real emotional enjoyment. In the past it's happened maybe twice for me - once many years ago, when I got may hands on a Naim CDS3, with a 272 and a stack of NAP250s. More recently with the DAVE (digital had always left me a bit "meh" until then, and now with the Grimm.....

I may be suffering from luddite syndrome, and I need to get off my ass and listen to other comparable kit (thinking Innuos Statement or Aurender A10), but I have thoroughly enjoyed using the MU1, to the extent that unless I find something better to my ears, I'll probably buy one...all in all, a very happy new year.

Note - in the pic, the screen is blurry as I left the protective film on (it's a demo unit) - the actual screen is crisp and clear).

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Jun 18, 2021 at 2:30 AM Post #2 of 49
Hi Bluecar, thanks for sharing your impressions :slight_smile:

In terms fo Nas vs Local, local wins by a long way. Texture is better, detail is better, musicality is better. Again, I don't know the technical details, but the act of playing the exact same rip form the local drive is much more resolved than playing it from the NAS store.
Thanks for trying local storage options, I currently use the MU1 with a NAS. Will give USB storage a try 👍
 
Sep 29, 2022 at 3:23 PM Post #3 of 49
MU1 is my new favorite thing. I went for a 4000 eur AES cable from Sin Audio 😂 But I swear I hear the difference!
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Oct 7, 2022 at 7:21 AM Post #5 of 49
Looks like a very impressive set of equipment you have there.
I've never heard of this cable company. What other AES cables did you compare it to?
Stefan from https://www.headphoneauditions.nl/ gave me a live demo of few other similarly priced cables. He works with them directly. I think the best thing is to fly and try in his Amsterdam shop. I would never have bought it without trying. I still have doubts believing AC cable magic :)
 
Oct 8, 2022 at 11:30 AM Post #6 of 49
I get my Grimm MU1 with 8TB SSD tomorrow! It will go into my system with a Innous PhoenixNET switch before it and a Bricasti M1SE downstream. I also have an Aurender W20SE in my other system so I have a good reference for comparison. I'll be using a Revelation Audio Labs cyro'd pure silver AES cable to connect the MU1 to the M1SE.
 
Oct 11, 2022 at 4:57 AM Post #7 of 49
Stefan from https://www.headphoneauditions.nl/ gave me a live demo of few other similarly priced cables. He works with them directly. I think the best thing is to fly and try in his Amsterdam shop. I would never have bought it without trying. I still have doubts believing AC cable magic :)
Well, even a dedicated audiophile would stop at flying to another country to audition a cable :). So I'm really curious what other cables you listened to? There can't be that many choices in the $4k ball park.

I'm very much an AES cable believer for the MU1, but I stopped at the $1k Sablon Bocchino.
 
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Oct 12, 2022 at 6:09 AM Post #9 of 49
Well, even a dedicated audiophile would stop at flying to another country to audition a cable :). So I'm really curious what other cables you listened to? There can't be that many choices in the $4k ball park.

I'm very much an AES cable believer for the MU1, but I stopped at the $1k Sablon Bochinno.
I flew in to try Grimm MU1 with/or instead of Mscaller, and the cable was just a thing I ended up getting. I will msg stefan to ask what I have tried.
 
Nov 19, 2022 at 9:30 AM Post #10 of 49
I flew in to try Grimm MU1 with/or instead of Mscaller, and the cable was just a thing I ended up getting. I will msg stefan to ask what I have tried.
Maybe you (or someone else) can help me. I am thinking about to replace my Innuos Zenith 2SE (better than Zenith 3), Phoenix USB and McScaler with a MU1 straight into Chord Dave. What are your thoughts?
 
Nov 20, 2022 at 9:54 AM Post #11 of 49
Maybe you (or someone else) can help me. I am thinking about to replace my Innuos Zenith 2SE (better than Zenith 3), Phoenix USB and McScaler with a MU1 straight into Chord Dave. What are your thoughts?
I had Chord 2yu+2go as a streamer into mscaler and the mu1 direct is better. The only downside is that mu1 has no usb interface and only supports rune. If you can live with that, I think that is better!
 
Nov 21, 2022 at 2:43 AM Post #13 of 49
If any of you are ever in Vilnius, I am would be very happy to give you a demo! I also recently got Fleetwood Deville
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speakers, they are simply something else.
 
Nov 21, 2022 at 4:19 AM Post #14 of 49
Maybe you (or someone else) can help me. I am thinking about to replace my Innuos Zenith 2SE (better than Zenith 3), Phoenix USB and McScaler with a MU1 straight into Chord Dave. What are your thoughts?
I replaced a tweaked NUC, M-Scaler, external LPS, ISORegen and 4 expensive USB&BNC cables, with an MU1 and a single great AES cable going into my DAVE.
Full story in the Grimm MU1 thread over at AS - this is the most comprehensive MU1 thread I've come across, and essential reading for anyone interested in the MU1.

The short version is that the MU1 made all those components redundant - by significantly improved SQ along with a simpler, downsized solution.
But you have to throw away many audiophile assumptions because it's based on a low-powered i3 NUC, SMPS, Roon-only music app, no USB of any consequence, etc. It just has a different approach to most rival TOTL servers/streamers.

Note also that MU2 (adding DAC, pre-amp and headphone amp into a same-sized box) is due next year, which may be interesting for those (like me) who ultimately want to downsize to a single-box TOTL headphone solution. There is currently no plan for existing MU1 boxes to be upgraded to MU2. And we don't know how good the new features will be.
 
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Nov 21, 2022 at 1:51 PM Post #15 of 49
I replaced a tweaked NUC, M-Scaler, external LPS, ISORegen and 4 expensive USB&BNC cables, with an MU1 and a single great AES cable going into my DAVE.
Full story in the Grimm MU1 thread over at AS - this is the most comprehensive MU1 thread I've come across, and essential reading for anyone interested in the MU1.

The short version is that the MU1 made all those components redundant - by significantly improved SQ along with a simpler, downsized solution.
But you have to throw away many audiophile assumptions because it's based on a low-powered i3 NUC, SMPS, Roon-only music app, no USB of any consequence, etc. It just has a different approach to most rival TOTL servers/streamers.

Note also that MU2 (adding DAC, pre-amp and headphone amp into a same-sized box) is due next year, which may be interesting for those (like me) who ultimately want to downsize to a single-box TOTL headphone solution. There is currently no plan for existing MU1 boxes to be upgraded to MU2. And we don't know how good the new features will be.
Thank you for your answer! I will tell within a week or two if the MU1 is able to sound as good or better than a Zenith 2SE with Phoenix USB and Audiowise DX-USB and MScaler with upgraded power supply (5 boxes and many cables!). But the Phoenix Net stays and I give it a try it with the MU1.
BTW - I have a SR Purple fuse with 2A slow blow 5x20mm. Is there a chance that I can use it with the MU1?
 

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