Grimm Audio MU2 "Major Dac"

[PYP]

It has been a while since I posted on this thread and have a few things to add to the mix. Six months with the MU2 and I can't imagine a legitimate need on my part to look for another dac/streamer for my digital only system. It is nice to have a piece about which I don't need to worry or consider changing.

My first attempt to clean up the noise was to install a grounding rod outside the house and have the electrician run two dedicated "home run" lines for stereo equipment only. I use the SR small passive grounding box that feeds into a wall unit. These two things brought a level of blackness or dark background not achieved by anything else to that point. Having heard it, I would never go back.

I then considered going down the Network Acoustics Tempus/Muon Pro filter and cable road. That was about a $6,500 toll. Instead, I went down the Dejitter It Switch-X and Wifi-X road through GTT Audio. This was a $4,350 toll. These latter pieces create a separate "clean" internet access point. Again, having heard the "before and after" I would never go back. At this point, if there is more noise to remove or darkness to achieve—I don't know how to gain it or if I could hear it.

That little SR grounding box works well in my setup too. As for the ethernet side, it seems you have taken all the steps to clean up the noise that is carried by ethernet cable. Once I thought I had taken reasonable steps to clean up the ethernet, it occurred to me that noise still travels via electrical lines and although my dedicated outlets help, the hifi is powered by what is essentially an electrical circuit.

In a separate room from the hifi, there is a router, TV and TV box. All are polluting devices by nature of their SMPS. Although they are all powered by a balanced power unit, a few experiments told me that noise on this common line was traveling back to the electrical panel and polluting the dedicated outlets too.

I'm trying one of these in the outlet that also powers the balance power unit: https://www.akikoaudio.com/en/products/product/akiko-audio-triple-ac-evolution-u-s Although it has only been a few days, I'm surprised by the clarity it brings. I can try it for 45 days but I already know it is staying. Once it has been in place for a month (burn-in time according to the manufacturer), I'll try it with the outlet that powers the Shunyata distributor.

 

[PYP]

A good and fair review of the MU2:

 

[Ron Resnick]

A good and fair review of the MU2:

I thought this was a great and genuinely informative and educational video, coming in at under 20 minutes.

 

[ukiro]

Yes, Tom's DAC reviews have been really great over the past year or so. He has truly put in the work to form a language around some of the emerging understanding of cutting edge D/A conversion. I think several of his expressions and mental models deserve to become defacto standards.

In this particular case I think his focus on spectral linearity, while not incorrect, took a bit of attention off of other strengths of the MU2. But I also understand why he wouldn't just want to repeat the consensus around fluidity and intoxicating naturalness that has emerged across other reviews. Though he does seem to pick up on these traits too.

I intend to make one more video about the MU2 (as my first one proved very popular, despite exceeding Ron's preferred 20 minute length preference) where I review the reviews, sort of a meta-analysis of all MU2 reviews to give an owner's perspective of what they got right and where I might disagree.

 

[PYP]

In this particular case I think his focus on spectral linearity, while not incorrect, took a bit of attention off of other strengths of the MU2. But I also understand why he wouldn't just want to repeat the consensus around fluidity and intoxicating naturalness that has emerged across other reviews. Though he does seem to pick up on these traits too.

I liked the linearity comments if one considers the context of system synergy. For example, the way my speakers are situated in the living room as well as their HF presentation (as designed), an overemphasis in the frequency extremes would not produce a natural sound overall.

The one area missing for me was more emphasis on how neutral/natural vocals sound. Human evolution has given us extraordinary sensitivity to voices. Addressing that gets a reviewer into the language of intoxication, etc.

 

[Kingrex]

In a separate room from the hifi, there is a router, TV and TV box. All are polluting devices by nature of their SMPS. Although they are all powered by a balanced power unit, a few experiments told me that noise on this common line was traveling back to the electrical panel and polluting the dedicated outlets too.

I'm not sure you have common mode noise from your tv and router if you are using a balanced isolation transformer. The Akiko could be addressing other noise. The 3rd, 5th and 7th harmonics off that equipment will walk right through and isolation transformer. But My Akiko Corelli does nothing to reduce their intensity. So I doubt the small tuning rod does either. I am pretty darn confident you can not reduce low level harmonics with a parallel device. You would need to remake the sine wave with a regenerator or a Inverter of some device as such. Atmasphere says there is an old filter that in Inline that can mitigate them.

 

[PYP]

I'm not sure you have common mode noise from your tv and router if you are using a balanced isolation transformer. The Akiko could be addressing other noise. The 3rd, 5th and 7th harmonics off that equipment will walk right through and isolation transformer. But My Akiko Corelli does nothing to reduce their intensity. So I doubt the small tuning rod does either. I am pretty darn confident you can not reduce low level harmonics with a parallel device. You would need to remake the sine wave with a regenerator or a Inverter of some device as such. Atmasphere says there is an old filter that in Inline that can mitigate them.

Well, you know a LOT more about this stuff than I do. I listen and then theorize as to the reason for an improvement. The improvement was not small, which truly surprised me. When I did a simple experiment of using a "better" power cord on the balance power unit, I assumed that the "better" power cord was filtering the noise going back to the breaker box because the sound of my hifi (in a different room and on its own dedicated circuit!) improved, but I don't know if that is true. I do know there was an improvement and that led me to experiment with the Akiko with that same outlet as the TV/TV box/router. The positive result led to trying another one in another room (same shared electrical line) for my computer/monitor/printer. More improvement.

The noise abatement never seems to end. A very recent upgrade of the power distributor (as Shunyata calls them) surprised me again. The combination of the two Akiko and the upgraded power distributor has resulted in my explorations of different kinds of music than I usually listen to. That is always a good sign and what this hobby is all about (for me).

From time to time, an audiophile friend and I reflect on the ideal diagnostic tool that would analyze your setup and provide guidance about the noise in the setup and the perfect ways to mitigate it. Our setups are very different, as is the power delivered (we live in different countries with different electrical standards), therefore we assume the solutions would be different. But who knows?

PS. the "tuning rod" is rather large and chunky. An evolution in their technology/design.

 

[PYP]

Grimm has just launched a major software update for the MU2 that includes UPnP functionality and Tidal Connect.

For now, I'm continuing to use Qobuz as integrated within Roon.

 

[aangen]

I may not jump into the upgrade too quickly. I need to read the release notes first.
Read the notes, and the new manual. I am jumping in. LOL

Ran the update, all is well.