@gerihifi I'm curious about how you arrived at - 7bB for the MU2. I assume you just iterated through various settings until your ears said this was the best setting.
Grimm Audio MU2 "Major Dac"
- Thread starter PaulB
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Hi, it's a general thumb-rule (my opinion) and not put it on max - always around 85% of max volume if preamp is attached. Also see Grimm FAQ:
MU2 FAQ - Grimm Audio
#1 Cannot log into Roon after database reset. After you performed a database reset you cannot login to Roon. Instead you are forwarded to the Roon login page. After returning to the Roon remote there is no response. To resolve this issue, please update your MU2 to firmware version V0.9.6 or...
www.grimmaudio.com
- This rule doesn't apply in setting done mentioned earlier, as you set the MU2 to "Fixed Volume"
- As advised with "fix volume" in roon device setup, this doesn't apply as well:
BTW: Eelco Grimm mentioned to me that MU2 nativley supports DSD up to 256 (I completly overlooked that) and they also do their magic 1.5bit instead of 1bit data conversation. I tested some DSD256 albums and I'm pretty impressed - highly recommended to test!
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For those who don't follow the MU1/MU2 thread on AS, Eelco Grimm responded to a query about the software update to add UPnP/DLNA functionality:
"The UPnP/DLNA function of the next big MU1/MU2 update will be JPlay and Audirvana certfied. It takes longer than expected due to external reasons I cannot comment on here, but also because this is a major firmware update that has impact on many aspects of the playback system. And also because the same software team has been working on the quite spectacular LS1 update that is currently in beta. Please keep a little more patience, we build all software completely ourselves for stability reasons and stuff like this takes time."
While I'm happy with Roon, it will be fun to experiment with the others and make a comparison.
"The UPnP/DLNA function of the next big MU1/MU2 update will be JPlay and Audirvana certfied. It takes longer than expected due to external reasons I cannot comment on here, but also because this is a major firmware update that has impact on many aspects of the playback system. And also because the same software team has been working on the quite spectacular LS1 update that is currently in beta. Please keep a little more patience, we build all software completely ourselves for stability reasons and stuff like this takes time."
While I'm happy with Roon, it will be fun to experiment with the others and make a comparison.
I have all the things that would let me test UPnP/DLNA, I doubt I will race to try them. The MU2 with a Muon Pro System is just fine with Roon. Those other programs just don't match up to the ease of Roon. Bah. Audirvana is like a puzzle that constantly changes. Have a large DSD collection? That stops it dead cold. Bah. (At least it did for me)
completely agree that MU2 with Muon Pro using Roon sounds like music. Period.
A friend who uses Audirvana has experimented with many, many settings. To him, that process is enjoyable. It wouldn't be for me. I think JPLAY makes sense when used with their server because that is the reason one would by their server.
But, these additional capabilities will expand the market for the Grimm Audio products and that is a good thing. The MU1, and especially the MU2, could change the perspective about the fact that enjoyable music playback need not impose complexity on the end user.
On another site there was a question about fixing the volume level. Eelco responded as follows (I highlighted the part that refers to the MU2's design):
"The procedure with the current MU2 firmware to achieve a 'fixed volume' is as follows:
1. Put Roon in 'Device volume' (always...).
2. Dial in the volume that you like the MU2 to play at. It can be any volume you like, just dial it in with the top control knob or Roon's volume setting.
3. Make certain that this preferred fixed volume level is at or below '0 dB' on the MU2 display.
4. Click 'fixed volume' in the GRUI web interface.
From now on the selected volume will always be used. The sound quality is the same for any selected volume level. The same electronics is always in the signal chain, the relay volume control system is part of the DAC buffer stage. With 'fixed volume' you just fix the MU2 volume control to a certain setting. So for the shortest and most transparent signal chain, leave out an external preamp. If you wish to 'color' the sound with an external preamp, that's perfectly fine of course. In that case you can fix the MU2 volume control as described above."
I'm currently trying the Roon setting at Device Volume instead of Fixed Volume which I have been using for some time. In casual listening, it sounds great. Will need to motivate myself to do a more A/B comparison, but those aren't much fun these days. Just listening to music is far preferable. The other experiment would be to lower the fixed setting below 0dB to determine what, if any, SQ changes result.
Currently trying the -7dB on the Grimm (Roon = 85). For this experiment, the Roon volume setting = Device Volume. Will try Roon Fixed Volume too.
These are not only fun experiments, they also demonstrate the MU2's flexibility.
Since the first day I hooked up my MU2 DAC I have favored its sound. I have favored it so much that until tonight I stopped using the DAC in my BACCH-SP adio. This was my previous favorite DAC. I had a passionate 3 month love affair with a Mola Mola Tambaqui someone sent my way. But hearing the MU2 I sold the Tambaqui without any thought or regret.
This week I picked up yet another pair of Stealth Audio V17 Sakra LE balanced interconnects. The same as I use to connect the Grimm MU2 to my Commander Preamp. Tonight I hooked the DAC outputs from the BACCH-SP adio to the Commander. I used a function on the Commander to match the perceived levels best I could. This allowed me to switch between the two DACs. It is surprisingly really, really close. I haven't picked a favorite yet, more study is needed.
For the Grimm MU2 setup, the MU2 streams to the endpoint in the BACCH-SP. It does all its processing and outputs a digital signal via SPDIF (Stealth Octava-T) to the MU2 and outputs to the Commander.
For the BACCH-SP, the MU2 Streams to the endpoint in the BACCH-SP and its DAC connects up to the Commander.
And of course there is the option to stream from the MU2 to the MU2 and take all that external processing out and listen to the MU2 in its pure state.
But the BACCH-SP, now armed with Optimal Room Correction as well as it's crosstalk elimination software pulls a lot of weight. It's fun to listen in different ways. For me BACCH processing always sounds best. You might feel differently.
Fun though!
This week I picked up yet another pair of Stealth Audio V17 Sakra LE balanced interconnects. The same as I use to connect the Grimm MU2 to my Commander Preamp. Tonight I hooked the DAC outputs from the BACCH-SP adio to the Commander. I used a function on the Commander to match the perceived levels best I could. This allowed me to switch between the two DACs. It is surprisingly really, really close. I haven't picked a favorite yet, more study is needed.
For the Grimm MU2 setup, the MU2 streams to the endpoint in the BACCH-SP. It does all its processing and outputs a digital signal via SPDIF (Stealth Octava-T) to the MU2 and outputs to the Commander.
For the BACCH-SP, the MU2 Streams to the endpoint in the BACCH-SP and its DAC connects up to the Commander.
And of course there is the option to stream from the MU2 to the MU2 and take all that external processing out and listen to the MU2 in its pure state.
But the BACCH-SP, now armed with Optimal Room Correction as well as it's crosstalk elimination software pulls a lot of weight. It's fun to listen in different ways. For me BACCH processing always sounds best. You might feel differently.
Fun though!
Interesting setup, but BACCH-SP and Grimm are very different DAC design approaches ;-)
I've to say, I completely stopped to play around with any kind of upsampling, room correction in my 2-way stereo setup. It is a never ending rabbit hole and distracts me from music listening (also too many sonic changes to source materials never intent to be).
MU2 is my roon core for any streamers in the house, Holo May KTE the DAC for my PS Audio SACD (I2S) & Pachanko Labs Constellation Mini SE server (have to try it with AES/EBU on the MU2 in a later stage). Abbas Audio also used for some other CD transports (SPDIF) and streamers.
No more DAC's/streamers for me the next x-years
Happy music listening!
Gerald
I have three rabbits in my home. And rabbit holes? More than I can count. (It isn't the bunnies fault)Interesting setup, but BACCH-SP and Grimm are very different DAC design approaches ;-)
I've to say, I completely stopped to play around with any kind of upsampling, room correction in my 2-way stereo setup. It is a never ending rabbit hole and distracts me from music listening (also too many sonic changes to source materials never intent to be).
MU2 is my roon core for any streamers in the house, Holo May KTE the DAC for my PS Audio SACD (I2S) & Pachanko Labs Constellation Mini SE server (have to try it with AES/EBU on the MU2 in a later stage). Abbas Audio also used for some other CD transports (SPDIF) and streamers.
No more DAC's/streamers for me the next x-years
Happy music listening!
Gerald
...as someone left the DAC rabbit hole, here my (sorry in German only) resume on the MU2 - unpaid and my private opinion
hificouch.world
HiFi Setups - Couchsurfing | Grimm Audio MU2 DAC
Der (ultimative) DAC der meine unruhige Suche beendet hat!
hificouch.world
Very nicely done (Google translation works fine). I'm currently trying a switch (already had a passive filter before the MU2) and agree with your conclusion that a switch designed for audio use is beneficial....as someone left the DAC rabbit hole, here my (sorry in German only) resume on the MU2 - unpaid and my private opinion
HiFi Setups - Couchsurfing | Grimm Audio MU2 DAC
Der (ultimative) DAC der meine unruhige Suche beendet hat!
The Grimm MU2 ticks off a lot of boxes for me as someone who is trying to reduce the number of boxes in his system. I have a question for users: I have a nice full function preamp that I would like to continue to use mainly because of the phono stage. I read that some here run their MU2 into a separate preamp rather than using the built-in analog preamp. Does the MU2 have line level analog outputs? The best solution for me would be just to run (preferably balanced) cables from the Grimm out to my existing preamp. Are these analog outputs the same or different than those that would drive an amplifier? Thanks for any input, Ken.
Yes.
Same.
Grimm Audio MU2 streaming preamplifier
For several months, my wife and I had been living in a cozy studio apartment in New York's Financial District while our apartment underwent substantial renovations (footnote 1). All the old furniture was sold or donated, and decades of accumulated stuff was subjected to triage (sell, donate, or...
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I use the MU2 with an external preamp using XLR cables (like many folks).
The reduction in boxes has a huge benefit to the sound since there is no external connection between streamer and DAC. All of the standard interfaces are compromises.
I have the Grimm MU2 as a contender for my forthcoming streamer / preamp upgrade, so I was wondering why the OP and others seem to ignore its preamp feature and send its analogue output to another preamp! Any good reason for that, apart from the second preamps' likely phono and other analogue input abilities?
I only use digital sources and understand the MU2 includes a Roon Core, so only a subscription required - no separate Nucleus or equivalent hardware. An I right in thinking this?
The MU2 ticks most of my boxes (apart from its price!), so I am hoping it can be used for Qobuz / Tidal streaming, Radio Paradise, Internet radio, other digital inputs (TV sound, etc), all controlled by Roon and directly powering my mono power amps - no other electronics. Does the MU2 do all that?
As a spin-off question, is there an alternative streamer preamp on the market that includes a Roon Core? I don't want extra boxes and the idea of including Roon's hardware requirements built into a streamer is an attractive proposition. Thanks.
PS - It's seems unfortunate that the MU2 offers no Sub Out (or even secondary pre-outs so that subs could be connected), or an HDMI for higher quality audio from a TV. Maybe these omissions explain who some use a separate preamp?
I only use digital sources and understand the MU2 includes a Roon Core, so only a subscription required - no separate Nucleus or equivalent hardware. An I right in thinking this?
The MU2 ticks most of my boxes (apart from its price!), so I am hoping it can be used for Qobuz / Tidal streaming, Radio Paradise, Internet radio, other digital inputs (TV sound, etc), all controlled by Roon and directly powering my mono power amps - no other electronics. Does the MU2 do all that?
As a spin-off question, is there an alternative streamer preamp on the market that includes a Roon Core? I don't want extra boxes and the idea of including Roon's hardware requirements built into a streamer is an attractive proposition. Thanks.
PS - It's seems unfortunate that the MU2 offers no Sub Out (or even secondary pre-outs so that subs could be connected), or an HDMI for higher quality audio from a TV. Maybe these omissions explain who some use a separate preamp?
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Same here, I'm using my Soulution 725 Pre via XLR to the MU2, nice match
MU2 does have all those features.
Best regards
Gerald
The MU2's own preamp requires no additional preamp and sounds very transparent. In my case, I find that the synergy between the Mola Mola preamp and MM amps is desirable.
The MU2 only requires a Roon subscription to work with Roon. You can add an internal SSD to the MU2 (order it that way to start or send back to the dealer later for installation) for a local library or connect to other network storage. If you have a huge library, you might want to check in with other users about any issues and the solutions they found. Both Tidal and Qobuz can be connected through the Roon interface. I use Qobuz and it works flawlessly 99.5% of the time. Roon allows me to see my entire library, or just the music stored on the SSD or just Qobuz.
Grimm is working on a software update that will allow the use of Audirvana, Jplay, Qobuz and Tidal connect. Internet radio is already accessible.
Regarding connections, see page 11 for a diagram of the back panel: https://www.grimmaudio.com/wordpress/wp-content/uploads/Manual-MU2-Hardware-v1.1.pdf Inputs are RCA and XLR analog and AES, SPDIF and optical inputs.
Then there is the sound. This is a very lyrical streamer/DAC. You connect an ethernet cable and you get beautiful music. It is nearly that simple. 5 year warranty. Has been completely reliable since first power up.
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