Grimm MU1 - has anyone got one, what else did you consider please?

[bigfool1956]

"delivery of digital data reliably isnt that difficult" but whilst getting it to work reliably is not the same as achieving good sound quality. My interest in the MU1 came about because of me being unhappy with the sound quality of Roon compared to ipeng and with the MU1 being designed around Roon I am interested to see if it has managed to remedy that issue.

Thanks for the note on a dealer suggestion but I contacted Grimm and they suggested a good dealer for me to contact.

When I reviewed the SMS-200 Ultra for the forum, I also felt that using Squeezelite was a sonic improvement over the Roon endpoint on that particular device. Not sure I mentioned that in the review though  

 

[Fourlegs]

When I reviewed the SMS-200 Ultra for the forum, I also felt that using Squeezelite was a sonic improvement over the Roon endpoint on that particular device. Not sure I mentioned that in the review though  

Ah, interesting. Thanks.

 

[Fourlegs]

Did you see it was reviewed in the December 2020 edition of a Hifi News, by Andrew Everard?  It gets their top accolade, Outstanding Product.   
 

No, I didn't see that. I will have a look. Thanks.

 

[Glissando]

No, I didn't see that. I will have a look. Thanks.

https://www.grimmaudio.com/reviews/hifi-news-mu1-is-an-outstanding-product/

You can view download the review from here

 

[Fourlegs]

https://www.grimmaudio.com/reviews/hifi-news-mu1-is-an-outstanding-product/

You can view download the review from here

Many thanks. That made it easy to find and it was interesting. I am very much looking forward to hearing a MU1.
 

Can I ask, do you have a particular interest in the MU1 yourself?

 

[tuga]

As the music data remains in the digital domain in and out of the MU1, and we are interested in any differences between the USB and 'conditioned' AES3 outputs, then this can only be inferred via a third-party DAC.

This is complicated by any further jitter suppression/galvanic isolation/re-clocking within the test DAC, so the 'best' may not express a significant difference.

That was certainly the case here as our three AESIUSB DACs — dCS Vivaldi One [HFN Feb '18], Mola Mola Tambaqui [HFN Nov '19] and Mytek Brooklyn [HFN Aug '17] — showed no significant difference in either distortion or A-wtd SIN via either USB or AES3 streams — right down to 0.00005-0.00007% (OdBFs to —30dBFs) and 118.5dB, respectively, for the Tambaqui.

There were minuscule changes in jitter revealed by each DAC [Tambaqui, Graph 1] amounting to mere psec.

The real explanation for the difference in sound between the MU1's USB and AES3 outputs lies in the first-stage 4x upsampling/filtering applied to the latter — a very high tap linear-phase filter revealed by its extended pre/ post ripples [black impulse and response, Graph 2].

By contrast the unprocessed USB output invokes the slower roll-off linear phase filter inside the Tambaqui [red impulse and response].

PM

.

Interesting findings.

The Grimm comes with an infinite-ringing multi-tap filter à la manière de Chord and it downsamples high-res data to a rate it considers optimal comme Benchmark.

 

[Fourlegs]

The Grimm comes with an infinite-ringing multi-tap filter à la manière de Chord and it downsamples high-res data to a rate it considers optimal comme Benchmark

Yeah, but that is not the main thrust of why they think it sounds good if I am reading correctly.  Anyway, the first task is to listen to one and so I will get on the blower on Monday and see if I can arrange that. 

 

[Glissando]

Many thanks. That made it easy to find and it was interesting. I am very much looking forward to hearing a MU1.
 

Can I ask, do you have a particular interest in the MU1 yourself?

Well yes and no

I would find it difficult to justify spending £10k on any item of audio. Also the concept of the product is something I would not purchase either as its highly integrated. As digital is still evolving I prefer to purchase discrete items so as things move on I can swap components out and relatively inexpensively slot a replacement in the chain.

I am however interested very much in how they have achieved the result and what components and technology they are using. They plan to release a standalone DAC in the near future which I suspect will include the DSP capabilities of the MU1 and hopefully the FLL clocking. There may be a possibiliy of constructing something with sound quality of the MU1 but from discrete components.

GRIMM dont exactly design their components all in house, they decide on the concept and use external consultants to design major parts of the overall product. Also as they are only 8 strong they must outsource the manufacturing to elsewhere?

Guido Tent has probably designed the clocking and jitter reduction side as its one of his fortes. Guido owns Tent Labs too http://www.tentlabs.com/ and produces his own range of hif products, DIY kits and componets. TentLabs XO-2 and XO-3 low jitter clock upgrades for DACs using sample rate converters http://www.tentlabs.com/Components/DACupgrades/xo23dac/index.html   XO-DACXO-DAC External DACs need that same low jitter clock! Industry solutions using off the shelf input receivers do not offer jitter at the levels a serious audiophile need. XO-DAC retimes the regenerated clock and delivers a new clock: equal frequency but at least 30 times lower jitter! http://www.tentlabs.com/Components/DACupgrades/XODAC/index.html

Peter van Willenswaard all the power supplies and regulation.

I would not be surprised if Bruno Putzeys has designed the digital processing side as Bruno was the designer of their very first product which was a DAC for professiona  use which is apparently a bit of a legend and still highly regarded today.

 

[Glissando]

As the music data remains in the digital domain in and out of the MU1, and we are interested in any differences between the USB and 'conditioned' AES3 outputs, then this can only be inferred via a third-party DAC.

This is complicated by any further jitter suppression/galvanic isolation/re-clocking within the test DAC, so the 'best' may not express a significant difference.

That was certainly the case here as our three AESIUSB DACs — dCS Vivaldi One [HFN Feb '18], Mola Mola Tambaqui [HFN Nov '19] and Mytek Brooklyn [HFN Aug '17] — showed no significant difference in either distortion or A-wtd SIN via either USB or AES3 streams — right down to 0.00005-0.00007% (OdBFs to —30dBFs) and 118.5dB, respectively, for the Tambaqui.

There were minuscule changes in jitter revealed by each DAC [Tambaqui, Graph 1] amounting to mere psec.

The real explanation for the difference in sound between the MU1's USB and AES3 outputs lies in the first-stage 4x upsampling/filtering applied to the latter — a very high tap linear-phase filter revealed by its extended pre/ post ripples [black impulse and response, Graph 2].

By contrast the unprocessed USB output invokes the slower roll-off linear phase filter inside the Tambaqui [red impulse and response].

PM

.

Interesting findings.

The Grimm comes with an infinite-ringing multi-tap filter à la manière de Chord and it downsamples high-res data to a rate it considers optimal comme Benchmark.

Yes I noted those comments too. If you look at some of the other reviews of the MU1 (like the one posted of Alpha Audio) and others have noted the sonic difference between the USB and AES3. GRIMM currently recommend the Tambaqui probably as its designed by Putzeys and believe he has designed the DSP in the MU1. GRIMM plan to release a standalone DAC MU2 next year. I would think Guido Tent has designed the jitter/clock functions and wonder how close you might come in performance/sonic terms using some of the components Guido sells under his Tent Labs brand? I have also been trying to find if any other DAC's or music servers also use an FLL clock. Perhaps a number of professional DAC's do, perhaps the like of DCS? So far I have not been able to find any which specifically reference their use in the product.

 

[Glissando]

FLL clocks are used mostly I believe in telecommunications but are equally applicable for use in Audio. There is a Wolfson paper here which discusses their product Wolfson Frequency Locked Loop (FLL)  https://d3uzseaevmutz1.cloudfront.net/pubs/appNote/WAN0209.pdf

 

[Glissando]

Interesting podcast with Darko and Bruno Putzeys covering many aspects of audio.

Digital is started to be discussed 37 minutes in.

 

[Glissando]

Interesting GRIMM audo blog article that talks about the digital processing in the MU1. Does not give that much away as to if its the same approach as Rob Watts but does emphasise the importance of power supplies, analogue design and their filter processing The “Pure Nyquist” filters of the MU1https://www.grimmaudio.com/publications/the-pure-nyquist-filters-of-the-mu1/

 

[Fourlegs]

Interesting GRIMM audo blog article that talks about the digital processing in the MU1. Does not give that much away as to if its the same approach as Rob Watts but does emphasise the importance of power supplies, analogue design and their filter processing The “Pure Nyquist” filters of the MU1https://www.grimmaudio.com/publications/the-pure-nyquist-filters-of-the-mu1/

I am probably more interested in how it sounds it truth be told.

I have talked to a dealer and hope to get one on home demo after Christmas.

 

[Glissando]

Have you considered one of these £4.5k in the UK EMM Labs NS1 Network Streamer https://www.stereophile.com/content/emm-labs-ns1-network-streamer

 

[Fourlegs]

Have you considered one of these £4.5k in the UK EMM Labs NS1 Network Streamer https://www.stereophile.com/content/emm-labs-ns1-network-streamer

No, have you heard one or seen any comparisons to any Innuos streamers to help me get an idea for comparison?

 

[Tarzan]

A toilet with heated seat? :mrgreen:

:bulb: