Grimm Audio MU1 and MU2 Music Players

[Spike]

My unit has frozen during firmware update to V1.5. After nearly 1 hour and no restart, I unplugged it since the manual said the update would fail and start again when powered up. That was a mistake. Now I have a white screen and power button and control disc are still unresponsive. Put in a ticket to Grimm. Any ideas?

[soupcon]

56 minutes ago, Spike said:

My unit has frozen during firmware update to V1.5. After nearly 1 hour and no restart, I unplugged it since the manual said the update would fail and start again when powered up. That was a mistake. Now I have a white screen and power button and control disc are still unresponsive. Put in a ticket to Grimm. Any ideas?

That sucks. Grimm will help. The one time I put in a ticket, they were on it as soon as they were open for the day.

[aangen]

I have been appreciating 2x. 

I have not been appreciating player function. Delays on next song startup, a few times the song started playing seconds into it. I don’t care for it. Sigh.

[TheAttorney]

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.

 

The web interface has several additions - including a Standby button and internal disc usage that owners have asked for.

Also now included is IR Remote programming, which prompted me to retry the IR Remote feature (I have previously posted that this significantly impacted SQ for me). Which leads me to report one issue:

 

When inserting, or removing, the IR dongle jack whilst MU1 is running, the MU1 crashes (blank screen) and can only be reset by powering the little power button on the back. Presumably the jack is temporarily shorting the input as it's moved, which is a normal jack limitation. I vaguely remember this caused the MU1 to hiccup in the past, but now seems to be more extreme. Anyway, I've stopped trying  the IR Remote, and hope the Grimm team is reading this and will investigate. 

[Eelco Grimm]

Dear TheAttorney, the IR issue you mentioned is known and has been fixed with later hardware. With the first few batches (that apparently includes your unit) you should indeed not plug or unplug the IR cable while the MU1 is on. Excuse us for the inconvenience.

[aangen]

2 hours ago, aangen said:

I have been appreciating 2x. 

I have not been appreciating player function. Delays on next song startup, a few times the song started playing seconds into it. I don’t care for it. Sigh.

 

 Reboot did not change anything. It’s really odd, I’m not accustomed to issues with my MU1.

[Eelco Grimm]

Dear aangen, Issues like this are usually related to Roon. Sometimes it solves itself after a while (probably related to indexing or so). Sometimes a Roon database reset is needed. Always make sure to regularly make Roon database backups so you can restore it after such a reset. If you need further assistance, please use the support form on our home page. I rather not use this forum to deal with private support questions.

[aangen]

Sorry my friend, it is just so very unusual. 

[Mike123]

The storage meter is a nice add, however, it's only reflecting 2TB when my unit is 8TB..

[Ronnie112]

Hi, was frequently checking this thread, but now after the update to 1.5 wanted to shout out how good it is. Don't know what it is, maybe disabling the connections (incl. circuits) not in use, but it sound all more....right.  Was impressed by the more fluid and easy presentation and the PRAT seems better as well. Thanks Eelco a d team for the early X-mas gift.

[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.

[mriguy]

Yep.... even before checking in on this thread, I too had a sense of just a touch more musicality following Grimm's 1.5 firmware upgrade. The great thing about the MU-1/Tambaqui combination is that I keep getting "recalibrated" on what is possible. What a blessing.

[soupcon]

On 12/19/2022 at 3:45 AM, Eelco Grimm said:

Dear aangen, Issues like this are usually related to Roon. Sometimes it solves itself after a while (probably related to indexing or so). Sometimes a Roon database reset is needed. Always make sure to regularly make Roon database backups so you can restore it after such a reset. If you need further assistance, please use the support form on our home page. I rather not use this forum to deal with private support questions.

i have had about 7 instances of corrupted Roon databases, and even associated problems with backups not happening. This is why I'm particularly interested in player alternatives on the Mu1 horizon. 

 

What is your view of any expected sonic changes with 1.5? ps thanks for an amazing product. 

[pvanosta]

Just chiming in regarding the update process: did my firmware update yesterday and it went through without a hitch. Trying to find some time for a proper listen over the coming days.

[zerung]

No happiness for my upgrade to 1.5

The unit searches and then says that there is an upgrade.

However the short push button is dark and I cannot choose this, so cannot upgrade.

 

Not sure why this is such a challenging hardware? 

[aangen]

My issue was a super easy fix. Eelco told me to reset to original settings on the MU1 and any issues I had vanished. I’ve been listening for five hours now and it’s outstanding+. Whew.

[pvanosta]

I just had a first listening session on MU1 FW 1.5 and Roon 1182. I have an issue with DSD and DSF files. Before, any DSD and DSF file in my library played without and issues. Now, any DSD.DSF file shows as playing in the Roon UI, but no sound is produced by the Mu1 / LS1 system. This goes for DSD64, DSD126 and DSD256 (auto-downsampled to DSD128 due to the limitation on the LS1 speakers). Everything else plays fine (24/192 etc).

 

Update: this issue only occurred when I switched the MU1 from 4x to 2x oversampling. I just switched back to 4fs oversampling and everything plays again...

[Eelco Grimm]

10 hours ago, pvanosta said:

I just had a first listening session on MU1 FW 1.5 and Roon 1182. I have an issue with DSD and DSF files. Before, any DSD and DSF file in my library played without and issues. Now, any DSD.DSF file shows as playing in the Roon UI, but no sound is produced by the Mu1 / LS1 system. This goes for DSD64, DSD126 and DSD256 (auto-downsampled to DSD128 due to the limitation on the LS1 speakers). Everything else plays fine (24/192 etc).

 

Update: this issue only occurred when I switched the MU1 from 4x to 2x oversampling. I just switched back to 4fs oversampling and everything plays again...

Good catch, that's a bug... We will look at it soon and solve it in an interim update.

Please note that DSD256 is converted to 4fs PCM natively by the MU1. Only rates higher than DSD256 need downconversion by Roon (which we do not recommend). 

[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. 

[TheAttorney]

10 hours ago, Low325 said:

 By default, there is Crossfeed, Parametric EQ and Audeze presets, all disabled.  I cant seem to remove them. 

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.

[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.  

 

[yellowblue]

I couldn´t believe my ears. After two days without listening and shutting down the MU-1 I decided to follow TheAttorney´s advice not to use Roon Radio. I also changed some Library settings to "Background audio analysis speed - Off" and "On demand audio analysis speed - Off". And finally my MU-1 opened up as I have wished from the moment I got back the MU-1 from Eelco Grimm (more than 200 hours burn in). Much more holographic and more depth. Grimm did a great job btw with a complete overhaul of the server - hardware and software. Needless to say that it sounds better now than with Zenith SE and MScaler - now directly into Dave with Jorma AES cable. 

[Ronnie112]

Concur with all findings above, Roon should be used as vanilla as possible to make the Grimm Mu1 shine. Leaving (or turning) all additional functions off really makes a difference. Also feel that dimming the display of the Mu1 is distinctively leading to a more black background and more airy highs.

 

This thread made me wonder if revoking the Grimm extension in Roon for enabling track information in the display, will lead to better SQ. Won"t need it anyway, with the display off. Will try it myself, but has anyone experience with this?

[pmorali]

@Eelco Grimm

In that you recommend minimizing using any of the DSP functionality in Roon, are you contemplating offering similar DSP functionality in the MU1 (ran on the FPGA)?  I am interested in particular in the convolution engine.

[TheAttorney]

On 12/30/2022 at 7:19 PM, yellowblue said:

... I also changed some Library settings to "Background audio analysis speed - Off" and "On demand audio analysis speed - Off". And finally my MU-1 opened up...

Well, I thought I'd come to the end of my Roon/MU1 tweaking days, but the above prompted me to have one more go.

 

Previously, I had compared analyzed files vs non-analyzed files and found little or no difference, which was a relief, as there's no easy way of "un-analyzing" already-analyzed files. But it seems that I may have been doing the wrong comparisons...

 

This time, I just toggled the above two settings on and off (on the same already-analyzed files), and this time there did seem to be a difference. As with many of these Roon tweaks, the differences can appear very subtle or very profound - depending on many factors.

And as with many of these Roon tweaks, there doesn't appear to be a rational explanation.  My best guess is that certain settings cause Roon to frequently be polling something to see if further action is required. Because Roon developers don't believe such background activities have any impact on SQ, they never bother to curtail such activities when they're not actually required. Either that, or it's all in my imagination.

 

Anyway, the bottom line is that these two settings are staying "off". I don't have the patience to go back and compare this tweak to the previous ones, but from memory, I'd put it high up in priority.

 

I do still make use of the file analysis, so I will temporarily enable the background analysis after importing new files into the library. Then switch it off again.