Grimm Audio MU1 and MU2 Music Players

[Low325]

17 hours ago, TheAttorney said:

My 1.5 upgrade went smoothly.

 

On first listen, I was underwhelmed by the SQ - seemed a bit flat. But then noticed that I had accidentally set the volume 3db lower than before. Doh! a reminder how easy it is to get hoodwinked during comparisons. Once I had set the correct volume, I agree with the recent consensus that 1.5 seems to have (incrementally) improved SQ. Can't put my finger on exactly what's changed - all the good things just got a little bit better.

 

Funny, you should say… I am experiencing a similar issue with SQ.  I know something is different, after 1.5.  There isnt a whole lot of settings even after the upgrade so I don’t know what it could be?  I’ll re-comb it again.  I am not using the MU1 for volume control as I have always used my amp’s gain knob.  Does anyone know if there a way to revert back to 1.4.x?

 

If anything, thanks to this thread and all the contributors.

[Low325]

On 12/19/2022 at 7:15 PM, Low325 said:

 

Funny, you should say… I am experiencing a similar issue with SQ.  I know something is different, after 1.5.  There isnt a whole lot of settings even after the upgrade so I don’t know what it could be?  I’ll re-comb it again.  I am not using the MU1 for volume control as I have always used my amp’s gain knob.  Does anyone know if there a way to revert back to 1.4.x?

 

If anything, thanks to this thread and all the contributors.

Okay only in an online forum where its fine to quote yourself :)

 

Anyway, it looks like I’ve figured out my problem after I did the 1.5 upgrade, and it was totally my fault but I wanted to make sure to do enough listening tests to confirm.

 

After the 1.5 upgrade my sound became flat, small, and the entire stage seemed to have collapse. I almost thought of selling it because I was so dissatisfied with the “new” MU1 sound. 

 

• I did a MU1 reset from the GRUI.
• Listened and immediately still perceived a huge (negative) change.

 

Luckily I have a Tambaqui to which I can use as a Roon endpoint and was able to switch the device in Roon.  Previously, I had listened to the Tambaqui as a streamer and thought it still actually sounded pretty good with no MU1 magic.  But I do prefer and just adore the magic the MU1 brings. (Difficult to describe)  

Anyhow, I searched for the exact same song for each device.  The MU1 being the core, I am still able to flip back and forth between Roon Device endpoints (hold that thought).

 

• In Roon I made sure I played the MU1 as the device
• Made sure all settings MU1 were as how I like it. 
  • mainly 4fs
  • and no output volume control selected as I use the gain control on my Bakoon.  Listened.
• Then I went into Roon and had the same song play the “other” device, the Tambaqui.

And it was in that moment that I can confirm there was something inherently wrong and that something had changed affecting the SQ - that had coincidentally happened around the time I did the upgrade.  After a grueling few days, I remembered something that I read the night before I did the upgrade…it was Chris’ (yes THE Chris lol) comments of MU1 where it was mentioned if anyone was using Roon’s Convolution DSP settings.  I was the curious cat and discovered Convolution and other settings in Roon and added them…fearing I didn’t want to play with them till the next day, I left them included but ‘Disabled’ in DSP.  (Bring back that thought of Roon Device endpoints here.)  Fast forward a bit, I did the MU1 upgrade and immediately went into listening, but of course, damage was somehow done.  When you add the Convolution Filter, I think it automatically adds a Speaker Setup Filter too.  Even though I had these two filters Disabled, it seemed to have brought a change that affected the overall sound/signal.  By default, there is Crossfeed, Parametric EQ and Audeze presets, all disabled.  I cant seem to remove them.  These are the same defaults I see for the Tambaqui device Roon settings.  I hit that Reset to default option for the MU1 device in Roon - redid a listening test with my “set it and forget it” settings in MU1 and immediately knew THAT familiar presentation.  

 

Moral of the story —- Roon is dangerous!  But also brings great capabilities. 

[Low325]

12 hours ago, TheAttorney said:

TBH, I couldn't tell from your description what exactly was the Roon problem that you eventually solved.

 

But you can remove the filters by entering each one and hitting the remove button on the top RHS of each filter display. Simply disabling the filters is not enough.

If you read through this thread, there are a number of Roon tweak recommendations to improve SQ (these generally apply to any Roon implementation, not just MU1's). I would class them as resulting in subtle/incremental differences, but it all adds up.

 

This sadly does include the use of Roon Radio. I like to use this function, so over time I've been trying to convince myself that RR makes little or no difference to SQ. But I have now conceded that it does indeed subtly impact SQ (a softening/smoothing effect), so I only enable RR when I'm in less critical discovery mode.

 

I added Convolution filter and Speaker Setup filters in the MU1 DSP settings - just me experimenting with Roon.  From my testing, this was the difference between both devices.  When you reset it to default the said (3) filters always show up.  Is mine different?  Though I see what you’re saying, I can remove them one by one. Kinda quirky if “Default” sets do show up….

 

Yes - totally get it.  I’m a DSP fan…i come from competing in mobile audio (moons ago) where you die without DSP.  I’ll likely play with some DSP over time.  I’ve got some funky room modes I’d like to address with every little help possible.

 

Roon is fun.  

 

[Low325]

It looks like the LS1Be or even the other ones use SEAS drivers.  I absolutely love LOVE SEAS (Say-Us).  We used to use their drivers in mobile SQ and have worked with the SEAS team in Norway to help tune the Lotus Reference tweeter in the mid 2000s.  Always impressed on how their mids measured impressively (okay that ~4.5k-5k dip should’ve never been there, but thats what the EQ was for 😝)  on the Klippel when tested by one of the guys.

 

But yes, if there probably is one speaker (system) that calls my name to cheat on my current ones would be the LS1Be,  I always have a soft spot for SEAS….  I mean it’s not even that… I would have never known the MU1 would be the “gateway drug”, taking it to the next level when things just became music - and then you throw in an element of ‘back in the day’… kind of says that the Grimm Eco system is worth serious consideration.

 

Roon - great interface, it is responsive like Spotify’s UI.  I’m really started to come around and like it sooner than I thought.  I’m a lifetime user as well.  But definitely other native apps are gaining popularity to their increased SQ compared to using Roon.

[Low325]

On 1/3/2023 at 12:34 PM, Nicholas Dong said:

I have tried your experiment, I found that the sound of Mu1's display at the default brightness is the most perfect, dimming the screen or turning off the screen will have some impact on the sound, which is different from some other devices, maybe Grimm Audio in  When debugging the sound, it is adjusted under the default brightness

 

In addition, for the Roon extension of the display, I feel that the sound will be lifeless after the extension is removed. This is the opposite of the usual experience. This is very strange. I believe everything I hear.

Wow, you have some great hearing differentiating the affects of MU1 SQ on it’s the screen brightness levels.  I would have thought just turning off the screen would give the greatest affect increase on SQ, not really something in the middle…?  Interesting.  How do I find out the default setting without resetting MU1?  Perhaps an experiment is order too with the extension..hmm?

 

On the subject of displays…there used to be a trick that you can turn off the white LED in v1.4.x. I used to be able to ‘wake’ it from a standby mode of sorts and it would I would be able to control the MU1 as normal with the white LED off. In v1.5 I am unable to stumble on this (bug?) anymore…

[Low325]

Small little update released today, 1.5.1. Went in without a hitch!

 

also if anyone is using a Tambaqui. You have an app and firmware update. In the firmware my requests have been answered about the dimmable LEDs lol!

[Low325]

20 hours ago, PYP said:

Also, there is an update for Roon.

I didn’t know!  Updates galore and the week is not even over yet! 

[Low325]

12 hours ago, PYP said:

@TheAttorneySince you like to experiment, have you tried an external grounding box with the MU1?

 

I've been reading about two.  Computer Audio Design is based in your general geographic area:  https://www.computeraudiodesign.com/gc1-ground-control/   And Shunyata Research is in the US:  https://shunyata.com/products/grounding/altaira/     

 

The logic of these devices makes sense to me.  The two designers seem to agree on the sources of noise (signal ground and earth ground) and a similar way to address it.   Both companies seem to believe in in-home demos, which is a positive sign to me.   

 

Given my setup, I'm most interested in anyone who has tried these with both the MU1 and the Mola Mola Tambaqui   (perhaps @Low325  is interested in doing my work for me?)   Neither the MU1 nor the Tambaqui has grounding posts on the chassis, so one of the spare inputs would be the logical point of connection.  

 

I'm also curious about how these might be used with the LS1 since I've been reading more about their architecture.  

 

 

I’ve never ventured too much into grounding units but i do love tweaks.  Though ive read about ‘grounding’ spare rca inputs with non powered devices.  I’ll take a look see at these.

[Low325]

Thanks for continuously sharing experiences within this awesome thread.  I  dont want to go down this rabbit hole either…but jeez I must say there are times, when I go …”hmmmm what just happened…” during a listening session…  But I was equating them to noise in the AC, of course I had no data to back it up, so I would chalk it up to placebo or just my mind so caught up with other distractions…

 

I do like to turn off my gear, and start up again.  ‘Rebuilding binaries…’ i always say to our customers ;-)

 

Anyway, I debated on adding this here on or on the tambaqui thread (but equally enough, credit to the tambaqui DAC too).  But does anyone else run SPDIF into the MU1 from their Tv out?  I do, and I have always been super impressed with just how full bodied, impact and clarity the sound of movies or even regular programming sound.  I know most of you have dedicated listening rooms, but I have a shared space, and with the MU1 being the hub, I downsized back to 2CH HT and packed u all my home theater components…!  For me, of course, I can only know technically how good its been sounding since, but just noticing how my family tends to just be more engaged at the material and catching them jump at those moments of surprise…perhaps just pure coincidence, too many variables.  That jitter-free special sauce is very addicting.  Whatever it is, I’ll take it!  

 

That said, with @PYP mentioning that the LS1 could be in his future…I just imagine how great that integration would be with the addition with the SB1s and 2CH HT.  Anyhow, i thought I’d just throw it out there as an added bonus to LS1 integration…as I understand it, even if you added 5 speakers, it wouldn’t translate Dolby or decode in that way, but just a small little added benefit for those of you who have shared spaces and are, like me, 75% 2ch listening and the 25% 2ch HT.

[Low325]

On 3/20/2023 at 5:46 PM, PYP said:

So, excellent value, great performance (yet to be heard), compact size/versatile placement options and blends in with the existing decor = winning combination.  

 

To each their own, but I think the LS1 variant in white is beautiful.  Dont delay, I encourage you to buy now/soon! :D

[Low325]

17 minutes ago, PYP said:

I like all the colors.  Thank you for helping me spend my hard-earned savings!  🧐 

 

If I do purchase, it will be the final molt before I become a butterfly and there will be no transformations after that.   Before the MU1, I thought I had my final setup, but it has thrown a curve in my expectations.  It is a special piece of gear as we know.  

Yep.  I get it… been considering Grimm ecosystem for many things that can come full circle; the MU1 has heightened the level of transformation in my system like no other piece before it.  Simplicity/Design, and philosophy.  The drivers they chose bring back so many good memories.  There is something about a copper phase plug (get your head out the gutter you sickos 🤨) 

[Low325]

MU2 has been announced. Closely trying to monitor all convos on the new box. 

[Low325]

@PYP MU2 still high on the radar for you?  A number of us have the MU1/Tambaqui combo and it’s been such pure joy.  I don’t know how I could find a way to demo in my home without having to sell up my current setup to fund the MU2. Trying hard not to scratch the itch for the sake of just scratching the itch since the Grimm/Mola tag team is great in terms of sonics.  Given the Mola is somewhat a third width of a typical component, it and the MU1 are so neighborly on the shelf.

 

Still, Grimm Audio sits in a special place in my journey of audio. I wish they had a showing at the recent Home Entertainment show out here in the west.

[Low325]

You can send them in but pay a fee from Grimm I think? 

[Low325]

Are you using the MU1 as core and endpoint?  How big is your library?

 

Never experienced a stop even when I have left it on for weeks btw. 

[Low325]

On 10/31/2023 at 1:40 AM, aangen said:

I run my Gryphon Ethos transport through my MU1. I also can choose to listen to it through the Ethos DAC directly. I love both but I lean to listening through the Grimm a bit more. Those inputs in the back, use them!
 

(This is not about streaming anything, no matter the source)

I agree.  I put everything through the Grimm MU1, toslink (from my TV), Ethernet, SPDIF in from an Spotify Connect streamer…its the central HUB, and it is outfitted with a 8TB internal disk.

[Low325]

@Ronnie112 fantastic!

 

Here’s to hoping #2 concern will be updated in the new firmware for the MU1. 
 

[Low325]

8 hours ago, stevebythebay said:

I use the etherREGEN (Swenson design) switch with its low jitter clock, and have tested footers from Herbie's and lately an EVP from Norm Varney (avroomservice.com) underneath to see if these have any impact.  Not that significant a difference.  However, with Caelin Gabriel's (Shunyata) cable supports or even the less expensive CVP's (Norm Varney again) there is a benefit in lowering noise, though not very dramatic.  Interestingly, like much of our home audio equipment, cable and footer settling in (in conjunction with connected components, makes a difference.  I've other tweaks in my system.  But these seem very specific to minimizing high frequency digital cable "radiation" affecting my Spectral amps.  The deeper I go down this audio system rabbit hole, the more I discover.  Maddening!

Did you ever do a comparison between norms stuff and the AUVA? I have Norm’s footers too but underneath my speakers stands. 

[Low325]

22 hours ago, stevebythebay said:

No.  I’m awaiting a set of 4 Auva footers for the MU1, which I’ve had for about a month.  As for Norm’s, I’ve had success with his EVP’s under my Revel Salons and subs, and some of my MIT network sections of speaker cables.  Never anywhere else…yet.

I can tell you’re a Norman fan with keywords like ‘airborne’ and ‘structural’ vibrations.  He’s become my most recent favorite too. Met him at a show and he is the kind gentleman you see online. 

[Low325]

The mighty MU1 still going strong, really love mine - never a hiccup with it and still such an integral piece in the chain.
 

Congrats  to all the MU2 owners, and hats off to the Grimm Audio team for what seems to be another tremendous product…! 
 

Looking forward to hear more reviews of the MU2. 
 

Also just want to give a really big shout out to the N.A. Grimm Audio rep. Outstanding support every step of the way for inquiries and professional service; (opting for an internal SSD.)

[Low325]

13 minutes ago, stevebythebay said:

Agree that John-Paul Lizars has been both responsive and diligent in reaching out to the tech folks at Grimm to get answers to my gnarliest questions. 

Thank you. I was a little distracted and for the life of me couldn’t remember his name as I typed!  He deserves to be mentioned for sure!  

[Low325]

Hans will probably have to create a ref 1c with the MU2 in place 😂. 

[Low325]

Well then, let me just go and gracefully shut down my lovely MU1, unplug for a few and get it started up again. 🙂 ahhhh - what a beautiful piece. 

[Low325]

Thanks for the update @stevebythebay !

my AUVA EQ are supposed to be here soon. 
 

If things pan out I would like to trial the 50s or 70s underneath my speakers. 
 

Stack audio mentioned the EQs are height adjustable?  

[Low325]

Yeah it was someone at stack audio that i was in touch with via email. He said the included manual will provide instructions.  Hopefully I’ll have mine soon. I’m actually using oreas under the MU1.  But as PYP mentioned earlier, my rack isn’t an aduiophile rack either. So perhaps there are still other airborne entities that resonate into the space and the structure the mu1 sits on. I have the worst kind. It’s basically a cavity I have my MU1 inside of.