Grimm Audio MU2 "Major Dac"

[PYP]

Someone posted on AS that Stereophile will review the MU2. I'm interested to read about their measurements. I already know what it sounds like and am interested in the relationship between measurements and performance. My simple conception of digital is that once the noise is reduced to a certain level, you are left with the music. But that means every component in the chain needs very low distortion. As many have commented, the source needs to be "clean" because GIGO.

 

[WLP3]

Has anyone tried selecting the Fixed Volume setting in Roon? What has been your experience?

 

[gerihifi]

I own it now for 5 months, NOT living my house again and had several Streamer/DACs here!

I use the Soulution 725 as Preamp and MU2 is connected through XLR (Driade Flow Reference). The MU2 is Set to 85% ( -7dB) volume level fixed. MU2 Pre is great, but had the Soulution before and to be fair it is a different level.

Also Eelco mentioned to me DSD Support through their propritary 1.5bit instead of 1bit. Have tested some native DSD256 and quiet impressed! Highly recommended in the price class €15k - €30k.



Rgds
Gerald

 

[PYP]

Has anyone tried selecting the Fixed Volume setting in Roon? What has been your experience?

Fixed Volume works well for me. In Roon's Audio settings: Volume control = Device Volume. In Grimm's web interface: Start-up volume = 0 bB; Fixed Volume is checked. As you can see from the post above, you can "fix" the volume at different levels. The terminology is not the same as back in the day when a transport could be set at either variable or fixed (meaning 100% volume only). With the Grimm, you choose the volume you want, then check the box to "fix" it.

 

[WLP3]

Fixed Volume works well for me. In Roon's Audio settings: Volume control = Device Volume. In Grimm's web interface: Start-up volume = 0 bB; Fixed Volume is checked. As you can see from the post above, you can "fix" the volume at different levels. The terminology is not the same as back in the day when a transport could be set at either variable or fixed (meaning 100% volume only). With the Grimm, you choose the volume you want, then check the box to "fix" it.

Have you tried using fixed volume in Roon?

 

[PYP]

Have you tried using fixed volume in Roon?

I'm confused by your question. By using the procedure I explained, the volume is fixed in Roon (all Volume Limits set to 100) and in the MU2 (fixed volume). The preamp controls the volume.

What settings are you considering changing or have changed in Roon?

 

[PYP]

I own it now for 5 months, NOT living my house again and had several Streamer/DACs here!

I use the Soulution 725 as Preamp and MU2 is connected through XLR (Driade Flow Reference). The MU2 is Set to 85% ( -7dB) volume level fixed. MU2 Pre is great, but had the Soulution before and to be fair it is a different level.

Also Eelco mentioned to me DSD Support through their propritary 1.5bit instead of 1bit. Have tested some native DSD256 and quiet impressed! Highly recommended in the price class €15k - €30k.

View attachment 133209

Rgds
Gerald

Beautiful setup. What brand is the rack? I typically don't like racks but this one is very nice.

 

[WLP3]

I'm confused by your question. By using the procedure I explained, the volume is fixed in Roon (all Volume Limits set to 100) and in the MU2 (fixed volume). The preamp controls the volume.

What settings are you considering changing or have changed in Roon?

Selecting Fixed Volume in the device settings in Roon rather than the Device Volume selection in Roon.

 

[gerihifi]

Beautiful setup. What brand is the rack? I typically don't like racks but this one is very nice.

Pure DIY, 30mm laminated veneer lumber, best dampening you can place 70kg per base without any issues.

 

[WLP3]

Selecting Fixed Volume in the device settings in Roon rather than the Device Volume selection in Roon.

In my system bypassing the volume control in the MU2 and using my integrated amp is a completely different experience. The soundstage is much wider and deeper and much more engaging. Using the Device Control setting in Roon and selecting the fixed volume option in the MU2 GUI and still using my amp to control the volume is not nearly as good.

 

[PYP]

Selecting Fixed Volume in the device settings in Roon rather than the Device Volume selection in Roon.

I know that doing so with the MU1 resulted in the volume control not working properly.

As for the MU2, this is from the software manual:
In Device Setup it is recommended to keep the default settings, if you have problems you might want to press the ‘Load defaults’ button in the top right corner.

8
You can change settings here but some settings will give problems, like changing ‘Volume control’. It should always be set to “Device volume”.

 

[PYP]

In my system bypassing the volume control in the MU2 and using my integrated amp is a completely different experience. The soundstage is much wider and deeper and much more engaging. Using the Device Control setting in Roon and selecting the fixed volume option in the MU2 GUI and still using my amp to control the volume is not nearly as good.

So, you are using the integrated amp to control volume in both of your cases, correct? Could you specify the settings you use for each alternative?

So, for Roon settings: Volume control setting in Device Setup, Audio device volume settings.

For MU2: startup volume, whether fixed volume is checked or not. If there are other settings you use, please include those as well.

Not disputing your results. All setups are different

 

[WLP3]

So, you are using the integrated amp to control volume in both of your cases, correct? Could you specify the settings you use for each alternative?

So, for Roon settings: Volume control setting in Device Setup, Audio device volume settings.

For MU2: startup volume, whether fixed volume is checked or not. If there are other settings you use, please include those as well.

Not disputing your results. All setups are different

 

[WLP3]

I am controlling volume with my integrated in either case.

Mu2 Fixed Volume

Device volume is selected in Roon. MU2 fixed volume is selected on the MU2 GUI. Sound is brighter and sound stage more compressed.

Roon Fixed Volume

In Device Settings in Roon fixed volume is selected. On the MU2 I have the volume set to +0.0 Db currently but could select whatever I want. I have the fixed volume selected on the MU2. Sound is much more natural and engaging. Soundstage is wider and deeper.

 

[PYP]

I am controlling volume with my integrated in either case.

Mu2 Fixed Volume

Device volume is selected in Roon. MU2 fixed volume is selected on the MU2 GUI. Sound is brighter and sound stage more compressed.

Roon Fixed Volume

In Device Settings in Roon fixed volume is selected. On the MU2 I have the volume set to +0.0 Db currently but could select whatever I want. I have the fixed volume selected on the MU2. Sound is much more natural and engaging. Soundstage is wider and deeper.

Thank you. Now I get it. I never tried the Roon Fixed Volume since the MU2 manual advises against it. Very interesting result. Good that you experimented and found it works for your setup.

 

[gerihifi]

I am controlling volume with my integrated in either case.

Mu2 Fixed Volume

Device volume is selected in Roon. MU2 fixed volume is selected on the MU2 GUI. Sound is brighter and sound stage more compressed.

Roon Fixed Volume

In Device Settings in Roon fixed volume is selected. On the MU2 I have the volume set to +0.0 Db currently but could select whatever I want. I have the fixed volume selected on the MU2. Sound is much more natural and engaging. Soundstage is wider and deeper.

I do exactly the same, if you have an additional PreAmp in between for talking care of the volume control, you should/need set MU2 to fixed volume, as well roon for this device to fixed volume.

If you are using the MU2 also with their (pretty good) Pre/Volume implementation, you should roon leave on default settings: Device volume (also recommended by Grimm).

 

[WLP3]

Thank you. Now I get it. I never tried the Roon Fixed Volume since the MU2 manual advises against it. Very interesting result. Good that you experimented and found it works for your setup.

I believe that @aangen is a proponent of the fixed volume setting in Roon as well. Takes the DAC from good to exceptional on my system.

 

[PYP]

I believe that @aangen is a proponent of the fixed volume setting in Roon as well. Takes the DAC from good to exceptional on my system.

I do exactly the same, if you have an additional PreAmp in between for talking care of the volume control, you should/need set MU2 to fixed volume, as well roon for this device to fixed volume.

If you are using the MU2 also with their (pretty good) Pre/Volume implementation, you should roon leave on default settings: Device volume (also recommended by Grimm).

Thank you, both! I have been waiting until my components are broken in to try anything new. I had an at-home demo for both a preamp (Mola-Mola Makua) and the MU2. Ended up getting both -- great combination. The MU2 was delivered first and is probably broken-in. But the Makua still needs some time. When the break-in cycle is at its positive point, the overall setup is very enjoyable.

But I will indeed try this simple setting change soon. And spread the word...

 

[PYP]

In my system bypassing the volume control in the MU2 and using my integrated amp is a completely different experience. The soundstage is much wider and deeper and much more engaging. Using the Device Control setting in Roon and selecting the fixed volume option in the MU2 GUI and still using my amp to control the volume is not nearly as good.

Since this setting is so easy to change, I thought I'd give it a try (Roon Device Output, Volume Control = Fixed Volume instead of Device Volume; then I closed and re-opened Roon just in case that might matter) even though my preamp is still breaking in.

With Redbook, the difference was subtle. Not so with high resolution. Yes, the result is exactly how you described. Will keep this setting and at some point will switch back to affirm my initial impressions.

Thanks for mentioning this!

 

[aangen]

Eelco Grimm posted this a day ago:

We regularly test the output of Roon in 'Device volume' mode to make certain that it outputs the data bit-transparent. We do not test Roon in Fixed Volume mode since in the past we have seen some issues in that mode and most people like to have the convenience of controlling the volume from within Roon so 'Device volume' is more important to us. I presume those issues are solved now, but if you use 'Device volume' you are certain that we looked after it. Note that with 'Device volume' you can still set the MU1 or MU2 to fixed volume in the GRUI web interface.