Grimm Audio MU2 "Major Dac"

[PYP]

Great feedback, thanks. I’m considering adding the MU1 to my Tambaqui, but (all things being equal which they never are) I prefer fewer boxes, and I certainly prefer buying fewer statement level power cords and AES cables. Not to mention likely skipping the preamp.

The MU1 + Tambaqui are a great combination. I had the Tambaqui for about 5 years and enjoyed every minute, more so when the MU1 was added. Recently had a demo MU2 to compare directly and subsequently purchased the MU2 (received yesterday). As @owen lawlor mentioned, this is a matter of personal preference since both are musically engaging (and provide a lot of value for the money). There is also the matter of system synergy.

Since I enjoyed the addition of the MU1, I became interested in the MU2. I too prefer fewer boxes, but it was the unique qualities of the MU2 that convinced me to make the change in my setup.

 

[owen lawlor]

The MU1 + Tambaqui are a great combination. I had the Tambaqui for about 5 years and enjoyed every minute, more so when the MU1 was added. Recently had a demo MU2 to compare directly and subsequently purchased the MU2 (received yesterday). As @owen lawlor mentioned, this is a matter of personal preference since both are musically engaging (and provide a lot of value for the money). There is also the matter of system synergy.

Since I enjoyed the addition of the MU1, I became interested in the MU2. I too prefer fewer boxes, but it was the unique qualities of the MU2 that convinced me to make the change in my setup.

Wow, congratulations on the MU2! Takes some 200 hours or so to break in. The first week of break-in is wild - lots of ups and downs. Enjoy in good health!!

 

[WLP3]

Wow, congratulations on the MU2! Takes some 200 hours or so to break in. The first week of break-in is wild - lots of ups and downs. Enjoy in good health!!

Mine coming on Saturday! Good to know about the ups and downs the first week. Sure hope it lives up to the hype!

 

[PYP]

Wow, congratulations on the MU2! Takes some 200 hours or so to break in. The first week of break-in is wild - lots of ups and downs. Enjoy in good health!!

@owen lawlor , thanks and thank you for that info! Nearing the end of week 1. In spite of a personal dislike for the breaking-in process, it has been fun.

All I can say is the "ups" provide a clear indication of something special -- an extraordinary ability to portray the vibe of the song/album. The Tambaqui had excellent PRAT, but this quality is something different. The better my equipment becomes the less I'm able to describe what I'm hearing.

Any time my wife asks if I've turned the music off, that is a very good indication that we are heading in the right direction.

 

[owen lawlor]

@owen lawlor , thanks and thank you for that info! Nearing the end of week 1. In spite of a personal dislike for the breaking-in process, it has been fun.

All I can say is the "ups" provide a clear indication of something special -- an extraordinary ability to portray the vibe of the song/album. The Tambaqui had excellent PRAT, but this quality is something different. The better my equipment becomes the less I'm able to describe what I'm hearing.

Any time my wife asks if I've turned the music off, that is a very good indication that we are heading in the right direction.

You bet, PYP, my pleasure. Once mine was burnt in I discovered a number of tweaks to push the unit to a whole new level. It's super sensitive to PC, IC and vibration control. I purchased a Puritan PSM156 and it was a huge leap, as is the Shunyata Sigma NR v2 I have on it. Added a Platinum Wireworld ethernet cable after trying a bunch and holy cow - like listening to local files on Roon! The most shocking tweak though was adding a Shakti Stone. Played around with placement all over the unit and the best turned out to be this one (pic attached). Someone on WBF had mentioned that it would double the performance of my SR switch and while it did make some big improvements I felt it robbed music of its energy thus tried on the MU2. It's perfect directly on the MU2 and doesn't press the control button down at all. I don't normally recommend gear but man, o man this was staggering. The already huge soundstage got even wider and deeper, sound was more settled and organic and just "right". I actually sometimes remove it and forget to replace it and start listening realizing something is not optimal and oops forgot to put the stone back. It's crazeeeeee!!! Anyways I am thinking about swapping the fuse next and trying to find the values. Thinking SR purple or pink. Anyone here try swapping fuses on this?

 

[WLP3]

You bet, PYP, my pleasure. Once mine was burnt in I discovered a number of tweaks to push the unit to a whole new level. It's super sensitive to PC, IC and vibration control. I purchased a Puritan PSM156 and it was a huge leap, as is the Shunyata Sigma NR v2 I have on it. Added a Platinum Wireworld ethernet cable after trying a bunch and holy cow - like listening to local files on Roon! The most shocking tweak though was adding a Shakti Stone. Played around with placement all over the unit and the best turned out to be this one (pic attached). Someone on WBF had mentioned that it would double the performance of my SR switch and while it did make some big improvements I felt it robbed music of its energy thus tried on the MU2. It's perfect directly on the MU2 and doesn't press the control button down at all. I don't normally recommend gear but man, o man this was staggering. The already huge soundstage got even wider and deeper, sound was more settled and organic and just "right". I actually sometimes remove it and forget to replace it and start listening realizing something is not optimal and oops forgot to put the stone back. It's crazeeeeee!!! Anyways I am thinking about swapping the fuse next and trying to find the values. Thinking SR purple or pink. Anyone here try swapping fuses on this?

I will be using a QSA Black/Red IEC adapter on a AQ Blizzard PC.

 

[WLP3]

You bet, PYP, my pleasure. Once mine was burnt in I discovered a number of tweaks to push the unit to a whole new level. It's super sensitive to PC, IC and vibration control. I purchased a Puritan PSM156 and it was a huge leap, as is the Shunyata Sigma NR v2 I have on it. Added a Platinum Wireworld ethernet cable after trying a bunch and holy cow - like listening to local files on Roon! The most shocking tweak though was adding a Shakti Stone. Played around with placement all over the unit and the best turned out to be this one (pic attached). Someone on WBF had mentioned that it would double the performance of my SR switch and while it did make some big improvements I felt it robbed music of its energy thus tried on the MU2. It's perfect directly on the MU2 and doesn't press the control button down at all. I don't normally recommend gear but man, o man this was staggering. The already huge soundstage got even wider and deeper, sound was more settled and organic and just "right". I actually sometimes remove it and forget to replace it and start listening realizing something is not optimal and oops forgot to put the stone back. It's crazeeeeee!!! Anyways I am thinking about swapping the fuse next and trying to find the values. Thinking SR purple or pink. Anyone here try swapping fuses on this?

Looking forward to playing with the Shakti Stone!

 

[owen lawlor]

I will be using a QSA Black/Red IEC adapter on a AQ Blizzard PC.

Interesting. Wasn't on the radar but do let us know how it turns out!

 

[PYP]

You bet, PYP, my pleasure. Once mine was burnt in I discovered a number of tweaks to push the unit to a whole new level. It's super sensitive to PC, IC and vibration control. I purchased a Puritan PSM156 and it was a huge leap, as is the Shunyata Sigma NR v2 I have on it. Added a Platinum Wireworld ethernet cable after trying a bunch and holy cow - like listening to local files on Roon! The most shocking tweak though was adding a Shakti Stone. Played around with placement all over the unit and the best turned out to be this one (pic attached). Someone on WBF had mentioned that it would double the performance of my SR switch and while it did make some big improvements I felt it robbed music of its energy thus tried on the MU2. It's perfect directly on the MU2 and doesn't press the control button down at all. I don't normally recommend gear but man, o man this was staggering. The already huge soundstage got even wider and deeper, sound was more settled and organic and just "right". I actually sometimes remove it and forget to replace it and start listening realizing something is not optimal and oops forgot to put the stone back. It's crazeeeeee!!! Anyways I am thinking about swapping the fuse next and trying to find the values. Thinking SR purple or pink. Anyone here try swapping fuses on this?

That is pretty wild (well, the Shakti Stone part). Unfortunately, I sold all but the two attached to the metal cover of my electrical junction box (above the dedicated lines for the hifi) and those are almost fused to the metal with thick double-sided mounting tape therefore I cannot experiment.

When I had the MU1, I found what you found about vibration control, PC, power conditioner and use the same setup with the MU1 -- Shunyata Denali for power, Kubala-Sosna PC and ethernet cable since all but the PC for the Denali are KS and Stack Audio AUVA footers.

I also continue to use the Network Acoustics Muon Pro passive filter before the MU2, but I prefer the KS ethernet to the one attached to the Muon Pro and therefore use a RJ45 to RJ45 coupler so that the KS can feed the MU2 (a clear improvement with the MU1). So far, my conclusion is that there is no need for a switch before the Muon Pro, but perhaps I need to test that opinion some day.

 

[WLP3]

That is pretty wild (well, the Shakti Stone part). Unfortunately, I sold all but the two attached to the metal cover of my electrical junction box (above the dedicated lines for the hifi) and those are almost fused to the metal with thick double-sided mounting tape therefore I cannot experiment.

When I had the MU1, I found what you found about vibration control, PC, power conditioner and use the same setup with the MU1 -- Shunyata Denali for power, Kubala-Sosna PC and ethernet cable since all but the PC for the Denali are KS and Stack Audio AUVA footers.

I also continue to use the Network Acoustics Muon Pro passive filter before the MU2, but I prefer the KS ethernet to the one attached to the Muon Pro and therefore use a RJ45 to RJ45 coupler so that the KS can feed the MU2 (a clear improvement with the MU1). So far, my conclusion is that there is no need for a switch before the Muon Pro, but perhaps I need to test that opinion some day.

I will also planning on using the Stack Audio Auva footers under mine as well. Are you using 3 or 4 footers? Apparently Eelco Grimm does not think there is any benefit to switching or filtering before the MU1 or 2 due to the reclocking/filtering/up sampling of the device.

 

[PYP]

I will also planning on using the Stack Audio Auva footers under mine as well. Are you using 3 or 4 footers? Apparently Eelco Grimm does not think there is any benefit to switching or filtering before the MU1 or 2 due to the reclocking/filtering/up sampling of the device.

I use 4 footers that are distributed as widely as possible without touching the existing feet. I did try 3 and thought that didn't work as well. When I experimented with the MU1, it took about two weeks for the footers to fully settle in, perhaps because the silicone supporter at the bottom of each footer is stiff when they are new. If you already have a great rack for your equipment, the effect might be small (I don't know since the furniture for my gear was made to fit the aesthetic of the room, not provide isolation for gear).

As for filtering, I agree with Hans Beekhuyzen that the effect isn't large for the MU1 (he has repeated this opinion for the MU2). I have wondered whether the MU2 is even more immune to common mode noise than the MU1, but haven't tried removing the Muon Pro to test that theory.

I also wonder if any re-clocking before the MU2 has any benefit and haven't tried switches as a result. My network is generic in the sense that the modem/router is ISP-provided and uses a wall-wart for power (plugged into an equi=tech power conditioner in a different room and different electrical circuit than the hifi). The MU2 is the only wired device on the network.

The more I engage with the music, the lazier I become with respect to testing all the variables. I have not experienced any major changes in SQ with footer or PCs. I was surprised by the relatively large effect of the Kubala-Sosna ethernet cable though. My conclusion is that it is worth trying different ethernet cables to see if this matters. All setups are very different.

 

[WLP3]

I use 4 footers that are distributed as widely as possible without touching the existing feet. I did try 3 and thought that didn't work as well. When I experimented with the MU1, it took about two weeks for the footers to fully settle in, perhaps because the silicone supporter at the bottom of each footer is stiff when they are new. If you already have a great rack for your equipment, the effect might be small (I don't know since the furniture for my gear was made to fit the aesthetic of the room, not provide isolation for gear).

As for filtering, I agree with Hans Beekhuyzen that the effect isn't large for the MU1 (he has repeated this opinion for the MU2). I have wondered whether the MU2 is even more immune to common mode noise than the MU1, but haven't tried removing the Muon Pro to test that theory.

I also wonder if any re-clocking before the MU2 has any benefit and haven't tried switches as a result. My network is generic in the sense that the modem/router is ISP-provided and uses a wall-wart for power (plugged into an equi=tech power conditioner in a different room and different electrical circuit than the hifi). The MU2 is the only wired device on the network.

The more I engage with the music, the lazier I become with respect to testing all the variables. I have not experienced any major changes in SQ with footer or PCs. I was surprised by the relatively large effect of the Kubala-Sosna ethernet cable though. My conclusion is that it is worth trying different ethernet cables to see if this matters. All setups are very different.

I am currently using the Auva EQs on my current Gold Note DAC and streamer. Using 3 per unit rather than 4...seems to be a bit more effective with 3 probably due to their light weight. I also have them on top of concrete patio stones instead directly on the veneered/particle board of the Pangea amp stands I have them on. It gives a bit more detail on concrete. Not sure how it will work out with the MU2 whether I will use the concrete stones or directly on the stands. I am using Stein Music Super Naturals (Matrix series) on other components but prefer the Auva on the front end gear. Also using Auva 100s on my speakers. Great product.

I am currently using Supra cat 8 ethernet cable and I am quite pleased with it. I am running it directly from the Xfinity router to the DAC with a iFi Lan iSilencer which seems to make a difference. I am lucky in that I have fiber optic cable which is fiber optic right into the router and there does not seem to be a lot of noise on the network. The DAC is the only wired device on the network. If I was to upgrade my ethernet cable I would need to add a switch since it is about a 50 foot run to the DAC. I'm not sure it would be worth it.

 

[WLP3]

You bet, PYP, my pleasure. Once mine was burnt in I discovered a number of tweaks to push the unit to a whole new level. It's super sensitive to PC, IC and vibration control. I purchased a Puritan PSM156 and it was a huge leap, as is the Shunyata Sigma NR v2 I have on it. Added a Platinum Wireworld ethernet cable after trying a bunch and holy cow - like listening to local files on Roon! The most shocking tweak though was adding a Shakti Stone. Played around with placement all over the unit and the best turned out to be this one (pic attached). Someone on WBF had mentioned that it would double the performance of my SR switch and while it did make some big improvements I felt it robbed music of its energy thus tried on the MU2. It's perfect directly on the MU2 and doesn't press the control button down at all. I don't normally recommend gear but man, o man this was staggering. The already huge soundstage got even wider and deeper, sound was more settled and organic and just "right". I actually sometimes remove it and forget to replace it and start listening realizing something is not optimal and oops forgot to put the stone back. It's crazeeeeee!!! Anyways I am thinking about swapping the fuse next and trying to find the values. Thinking SR purple or pink. Anyone here try swapping fuses on this?

I just received mine today. Unfortunately I have a terrible ground hum when it is plugged into the circuit. Did you experience anything like that? Unlistenable. Thoughts?

 

[owen lawlor]

The MU2 has ground hum? Sorry to hear that. Doesn't sound right to me. You may want to contact your dealer. It's an extremely quiet unit. Have you had issues with any other equipment? Sometimes things happen in shipping. I received a D'Agostino Progression integrated last year and a wire harness came loose in shipping. I was happy that I opened it up and reattached the power wire and it was right as rain. Even when I sold and shipped it. Only way to know for sure is to open and inspect it if you feel inclined....

 

[GHasley]

Ground hum....same plug? circuit? power distribution? cable(s)?

 

[WLP3]

The MU2 has ground hum? Sorry to hear that. Doesn't sound right to me. You may want to contact your dealer. It's an extremely quiet unit. Have you had issues with any other equipment? Sometimes things happen in shipping. I received a D'Agostino Progression integrated last year and a wire harness came loose in shipping. I was happy that I opened it up and reattached the power wire and it was right as rain. Even when I sold and shipped it. Only way to know for sure is to open and inspect it if you feel inclined....

Thanks, Owen, for your response. I have never had a grounding issue in my room ever. I have contacted my dealer and also Grimm on the issue. They are rather specific in the manual about plugging it into a grounded outlet with your other equipment. I have always separated my amp from the front end on a separate outlet. I wouldn't think that having it on a separate outlet would be that much of an issue. I certainly would not be surprised if something came loose in transit. It came in from the Netherlands to LA and trucked cross country to Michigan. The box it came in sure looked like it had some miles on it. I will use a 3 prong to 2 prong adapter to see if it goes away, but that is obviously not a long term fix. It is too bad because I can hear the potential through the horrible hum. Voices are amazing and soundstaging very precise.

 

[WLP3]

Ground hum....same plug? circuit? power distribution? cable(s)?

Same plug as previous front end directly into the wall. Never had an issue before.

 

[WLP3]

Same plug as previous front end directly into the wall. Never had an issue before.

On the same circuit as amp but different outlets.

 

[PYP]

sorry to hear that. Agree that the MU2 is extremely quiet and on its own does not hum (usually). Hopefully, the dealer can troubleshoot the problem.

Problems can occur during transit. When my audio dealer received my Tambaqui trade-in, he found it DOA. Was absolutely fine up to the moment I unplugged it to cool down prior to packing it.

On the positive side, you can already hear some of its qualities.

 

[WLP3]

sorry to hear that. Agree that the MU2 is extremely quiet and on its own does not hum (usually). Hopefully, the dealer can troubleshoot the problem.

Problems can occur during transit. When my audio dealer received my Tambaqui trade-in, he found it DOA. Was absolutely fine up to the moment I unplugged it to cool down prior to packing it.

On the positive side, you can already hear some of its qualities.

It looks like it was a ground loop, but I never had an issue with my previous DAC. Not sure why it is an issue with the MU2. I would prefer a more elegant solution than slapping a 3 prong to 2 prong adapter on my amps power cord.