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
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
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).
