Grimm MU1 Streamer - Really "The Best"?

My initial thoughts on the MU1 (streaming until I get my hard drive issue resolved) - fantastic. As expected. Perfect solid tangible detail.

I’m also using an old, non-current generation Cardas AES cable until my premium cable arrives. The dealer who sold me this old cable (purchased while traveling) wasn’t even able to identify the model - we only know that it is green! We found a few examples of sales on Audio Mart to figure out that it was pretty much the most entry level AES HiFi cable you can get, and it was old.

With that HUGE caveat - and I can’t stress that enough - I really enjoy the sound of the MU1 and I really enjoy the sound of my Innuos gear, both feeding the Tambaqui. The MU1 is clearly more capable when it comes to detail - the details and texture of electric guitars leap out of my speakers in such a tangible, raw yet refined, and different way. The Innuos by comparison is smoother, but not in a way that you notice missing detail unless you do a direct comparison. Unexpectedly, the Innuos gear has a fuller and more linear, 3D depth presentation - but I think that may be due to my very basic AES cable I’m using currently with the MU1. The MU1 has way more, I was going to say hardness but that would give the wrong impression - more impact and grit than Innuos. From snare drums to kick drums and bass, the impact and pacing is fantastic and better than with the Innuos. I’ve also now noticed that the Innuos Zenith plus PhoenixUSB Reclocker have a forward presentation of mids and treble. This makes vocals “pop out” a bit more, with very smooth vocals and treble. The vocals are slightly more enjoyable on the Innuos currently due to that “pop-out” effect and the smoothness.

Again, so important - I am probably just describing the limitations of my current very basic and old AES cable, so it’s not as if I’m forming any conclusions whatsoever with the MU1 at this point! I also notice very little difference between the 4X and NOS modes, but again, that is likely due to being performance-capped by my AES cable.

I also tried the MU1 direct to my Diablo 300 DAC and it sounded very enjoyable - with less detail than with the Tambaqui but really enjoyable. Do I like it better than the Innuos in this configuration? I think so, but too early to say definitively.

Not sure where every combination will land in terms of what I will LIKE the most, but I’m going to wait until my cables arrive to figure that out! I expect the cables to change a lot, especially in terms of spatial positioning/imaging, dimensionality and depth.

Unexpectedly, the Innuos gear has a fuller and more natural depth presentation

Right there….

I would personally NOT want to replace a piece of gear with those two attributes with an alternative that yields a lesser result. Less full, and less natural depth.

But that’s just me.

On another note, my friend who was getting the Grimm MU1 is going silent. I don’t want to bother him with questions. Give him the proper time to evaluate 

@thyname , I didn’t mean to imply the Innuos sounds fuller in tone or body; I meant a fuller soundstage depth. But now that I think about it, the Innuos is slightly fuller in body. The MU1 is by no means lean in tone however. It’s got a very even balance to my ears and things definitely don’t sound leaner or brighter with the MU1.

important to re-emphasize just how basic my cabling is right now - I have the cheapest possible AES cable (with the MU1) and balanced interconnects in my system currently, and will be about to go to the other end of the spectrum in a few weeks. With my Innuos gear I have my Audioquest Diamond USB cables which I’ve found to be fantastically transparent with great depth and I found to be great value compared with far more expensive cables (Nordost Valhalla 2 for example). So, currently my Innuos gear has an advantage over my MU1 in my system I think. The new interconnects will add depth and separation too so I think things will change dramatically for both Innuos and the MU1 when these cables arrive.

The ONLY thing that bugs me slightly about the MU1’s sound - and I really think I should probably be saying what bugs me about my really old basic Cardas AES cable’s sound - is that the soundstage depth doesn’t totally sound consistent / even / linear compared with Innuos / Audioquest Diamond. I notice this the most with vocals.  Could be that my speakers need some placement/toe-in adjustment as well.

Oh one other thing, I see Mola Mola advertises that the Tambaqui has specific filters for each input - USB, AES, etc.  So these differences presumably have an impact. 

Updates! First, I fixed my MU1’s hard disk myself. After Eelco mentioned in his note that the issue may be related to the hard disk’s USB connection not being connected, I thought that would be the simplest thing to fix. So tonight (while watching M3gan with my daughter, so I desperately needed something to do while enduring that pain…) I opened the chassis, and sure enough, the USB connector wasn’t inserted in the PCB’s port. Plugged it in and problem solved. And I got to check out the inside of the MU1 and snapped some pics of the PCB’s and cabling.

Second, I disabled the MU1’s volume control. I don’t know if this has a positive impact on sound quality, as it apparently does with some DACs.

Third, I toed in my speakers quite a bit more.

The results are breathtaking. Everything on the MU1 sounds absolutely perfect now. Soundstage depth is full, even and natural now. And vocals are spectacular and intimate. Like a “window into the recording studio” as some have said. The level of of precision is stunning. I think Innuos still has a more full body but this is bloom which is not as realistic. The 4X OS is more noticeable over NOS now - but still more subtle than I expected. It’s as if some barriers are removed and everything becomes ever so slightly more free and extended. I hear it in the upper mids and treble the most - becomes sweeter and more free sounding. Punk and grunge music with blaring guitars sound absolutely vicious in such a good way. All this detail and it’s really the opposite of fatiguing.

Tonal balance on my overall system sounds great - overall full balance with lots of bass that is so, so well defined and controlled, and as I mentioned before the impact and slam is just way more solid than my Innuos setup at all frequencies. Price point wise, not factoring the added cables, the Zenith Mk3 and PhoenixUSB cost a bit less than the MU1. But the MU1 still costs less than an Innuos Statement (non Next-Gen).

Another thing. As I mentioned I’ve been having issues with poor quality power lately. Yesterday around dinner time was the absolute worst I’ve ever heard - everything became a soft spongy mess while I had my Innuos gear running. Not enjoyable to listen to. Switched it over the MU1, and it sounded like music again. There was enough separation and impact that the MU1 was able to cobble together a coherent musical presentation with a worst case poor quality power scenario.

I think the speaker placement adjustment made a huge difference. Was needed to deal with all the extra detail that is coming through now.

Pretty happy with the MU1 at this point! The detail and impulse control reminds me of what is more easily achieved with an excellent headphone setup. Which is not easy for a full system to be able to do. And most importantly it’s very, very musical -  however you want to define that.  For me it means it sounds like people making music that conveys emotion and a feeling, as opposed to a HiFi system. Not dry/cold/analytical/lean at all!