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.

 

[gerihifi]

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.

I personally would NOT go for the upgrade, if you dont need Tidal Connect or UpnP, why?
- it means more services are activated as in the current release (for me a no go)
- I do not need latest Linux kernel updates, as I've not seen any major audio library updates
- upnp is for me not an option, having roon core (even Antipodes says the oppsoite and prefer UPnp over roon) and Grimm has a perfect Implementation already. Why would I need roon bridge in addition (Griims roon core Implementation is rock solid and if you not the upsample-everything-guy, perfect)?

https://www.grimmaudio.com/wordpress/wp-content/uploads/MU2-change-log-document-v1.0.1.pdf

- all new features for me useless in my roon-only setup (would only prefer to test Qobuz connect, but not yet implemented)
- THIS is what I'd ask Elco Grimm exactly what it means: FPGA: Various improvements to timing and power usage. ..would be my only reason to upgrade!

My 2cents.
Gerald

 

[aangen]

And never accept a free breakfast either!

 

[58spdstr]

Update took 15 minutes max. While I’m also a dedicated Roon based streamer, I now have some additional capabilities to explore and was curious about how/whether the DAC performance would be impacted. To my ear an enhancement in the lower registers without losing any sense of linearity or performance elsewhere. Noticeable when streaming and using the CD transport. I’m interested to see what others think. I didn’t have an expectation that it would sound different, but it does in my system and a little more bass presence with the MU2 is a good thing IMHO.

 

[PYP]

Update took 15 minutes max. While I’m also a dedicated Roon based streamer, I now have some additional capabilities to explore and was curious about how/whether the DAC performance would be impacted. To my ear an enhancement in the lower registers without losing any sense of linearity or performance elsewhere. Noticeable when streaming and using the CD transport. I’m interested to see what others think. I didn’t have an expectation that it would sound different, but it does in my system and a little more bass presence with the MU2 is a good thing IMHO.

That is interesting. Since my power distributor is still burning in, there are too many variables for me to form an opinion. The updated distributor was already clarifying the frequency extremes. But, the bass has always been very present in my setup with the MU2. The drum kit, upright bass and piano among others are convincing (mostly listen to Jazz). How convincing relies upon the engineering of individual recordings, or course. The MU2 lays out each recording as its own "experience."

At any rate, glad you are getting a positive result. I've come to think that no matter how much one upgrades other equipment around the MU2, it will show what a truly great piece of gear it is.

 

[tom539]

Hello to all,

currently thinking about stripping down my streaming setup to a 1-Box solution, so verry interested to the MU2.

Use a Antipodes K50 G4 and Soulnote D2, connected via USB („Siren“ from Ideon Audio). All power cord are „Silverdart“ from Zafvino, HY-3 rack from Solidsteel.
Integrated is SIA-025 from Vitus, connected via XLR (Accustic Arts „Reference“) from the D2. Speakers are TAD CE-1.

On the K50, I mostly prefer Squeeze only in terms of sound quality, but for user expirience, I also have Roon-Lifetime and HQplayer license.

What could I expect with the switch to the MU2 in terms of sound quality?
Better, worth or Just different?

Will have a demo Unit of the MU2 the next weeks and compare it at home.
Will also keep the Vitus as Integrated.

Thanks for any thoughts and a nice weekend.

atb, Tom

 

[PYP]

Having never heard the components you have, I cannot venture a guess at the difference.

For the MU2 demo, I suggest leaving it on at all times. It may take 1 - 3 days to fully settle in. No need to wait to listen to music, however. Hopefully, the unit has 300 hours (or so) of play time already. Like all digital, it takes some time to burn in.

Ask the dealer if it has the latest software. While the latest software may not sound different, it does look a bit different via their web interface (called GRUI). In the GRUI, since you are using the Vitus for volume control, you set the MU2's "startup volume" at 0 and "fixed volume" at 0. Perhaps your dealer has already set it up this way for you.

Then, you just play your favorite music. Have fun!

 

[tom539]

@PYP

The MU2 is the demo unit of the dealer from last year - so it should already burned in…
It has 8 TB SSD installed, I would Play my file from this local disk (as I normaly do with the K50.

Thanks for the info of volume settings.

atb, Tom

 

[coldbru]

@PYP

The MU2 is the demo unit of the dealer from last year - so it should already burned in…
It has 8 TB SSD installed, I would Play my file from this local disk (as I normaly do with the K50.

Thanks for the info of volume settings.

atb, Tom

Interested in your impressions.

 

[tom539]

Interested in your impressions.

Unfortunately, that won't happen anymore - the dealer sold the demo unit at short notice.

atb, Tom

 

[tdx44]

Hello to all,

currently thinking about stripping down my streaming setup to a 1-Box solution, so verry interested to the MU2.

Use a Antipodes K50 G4 and Soulnote D2, connected via USB („Siren“ from Ideon Audio). All power cord are „Silverdart“ from Zafvino, HY-3 rack from Solidsteel.
Integrated is SIA-025 from Vitus, connected via XLR (Accustic Arts „Reference“) from the D2. Speakers are TAD CE-1.

On the K50, I mostly prefer Squeeze only in terms of sound quality, but for user expirience, I also have Roon-Lifetime and HQplayer license.

What could I expect with the switch to the MU2 in terms of sound quality?
Better, worth or Just different?

Will have a demo Unit of the MU2 the next weeks and compare it at home.
Will also keep the Vitus as Integrated.

Thanks for any thoughts and a nice weekend.

atb, Tom

Hi I dont have the exact same gear to do a comparison but I did have he K50 G4 (with a MSB Premier) and just a brand new MU2. It still needs burn in and stuff but from the get go I can say it is at least equal and probably a bit better than the already really good K50/Premier combo. The fact that it costs less, takes up much less space and needs far fewer cables is the reason I switched to begin with. But the sound quality is definitely what's making me keep it.

Any questions you have dont hesitate, if i can answer them I will.

 

[PYP]

Hi I dont have the exact same gear to do a comparison but I did have he K50 G4 (with a MSB Premier) and just a brand new MU2. It still needs burn in and stuff but from the get go I can say it is at least equal and probably a bit better than the already really good K50/Premier combo. The fact that it costs less, takes up much less space and needs far fewer cables is the reason I switched to begin with. But the sound quality is definitely what's making me keep it.

Any questions you have dont hesitate, if i can answer them I will.

that is very interesting since the MU2 is new. But the midrange sounds very good within a day or so, therefore a lot of its character can be heard before full break-in. In my setup, the bass took a while to develop fully and HF, as usual, took time to reach full refinement.

But that is breaking the sound it into parts. What it does best is to disappear and the music is just there. A very lyrical player!