The MU1 speeches

MU1 team at Van Abbe

On January 31st 2019 the MU1 Music Player was officially introduced to the press, dealers, customers and friends during a special event in the Van Abbe museum of modern art in our home town Eindhoven. After speeches by some of MU1’s prime developers, all people who contributed to the development of this keystone product came on stage, as pictured on the right. It was a moment of great pride.

For those who could not attend the event, we offer transcriptions of the speeches below. Please enjoy.   

Eelco Grimm

“Luctor et emergo – struggle and emerge – is the motto of the people of Zeeland, in the south west of The Netherlands, but it could also be the motto of the MU1 project. It has a scope, larger than any project we ever did before. Our small team has built something that normally is only established by real large hifi companies. And often even these large companies just buy an off the shelf solution. So why did we go there?

Well, I had a dream. Grimm Audio’s mission is to set new audio frontiers by making the music chain more transparant. To reach that goal we need to explore new territory and for that we need full freedom to go where-ever we want. And that freedom comes at a price. 

The MU1 music player is a hub between you and the digital music world, online and local. And we like that hub to be transparant to the music. To achieve that it first of all has to be very accurate in clock stability. We know that for a long time and we are specialists in low jitter clocks. But we learned that this hub also has to be more accurate than we could ever imagine, when it comes to digital processing like upsampling and downsampling. So we decided to develop our own FPGA processing platform of extremely high precision and combine this with a very stable Linux PC. 

This brings me to the second reason to build the MU1. Media players often make me feel nervous. They sound different, depending on the processor jobs etc. I don’t want that. I want a music player to be stable and reliable. And always be confident that it runs smoothly.

And if we put so much effort in this device, it better be attractive too. For the user interface we selected Roon Labs. They allowed us to run both Roon Core server and Roon End Point in one box, which makes it very convenient for the user. And of course the box had to be beautiful. For this we hired the talented industrial designer Michiel Uylings who amazed us with the design of this extremely beautiful MU1. 

Now to envision a device that is attractive, reliable and precise is one, but to build it is a much more complex thing. And for that I like to hand you over to project leader Justin.” 

Justin Vis

“My name is Justin Vis. I am working with Grimm Audio for a while and the last two and a half years I have been working on the MU1 music player project.

At Grimm Audio we want to be in control of the audio. We want every part of the audio to be played back perfectly to the speakers. To get in control, we design and build analog discrete systems like very low jitter oscillators and low noise power supplies. But this time with the media player, we had to go further and enter the digital domain too. To acquire full control here too, we cooperated with our friends Gertjan and Pieter who offered us their high performance processing algorithms. These run inside an fpga chip. An fpga has a large collection of basic digital modules, that the designer can control to a large amount. It excels in running several high speed, high precision processes at the same time, which is exactly what we need for upsampling and downsampling. 

So I designed kind of a high end ’sound card’ around a powerful fpga. The communication between this fpga board and the CPU mother board that runs the user interface needs to be very stable. Again we want to be in full control. So we decided to use a fast PCIe interface and my colleague Michiel Schriever and I wrote our own DMA controller that guarantees a fast and stable communication. For the PC we selected a powerful fan-less NUC that can runs both Roon Core and Roon End Point so the MU1 becomes a one box solution.

As you can imagine, to have all these high speed electronic devices in a compact enclosure can be a threat to sensitive circuits like our low jitter oscillator. To stay in control, we developed our own switch mode power supplies and took EMC practice very serious during layout and evaluation.

It has been a tough ride at times, but we succeeded and I am very proud to present our little baby to you today.”

Gertjan Groot Hulze

“I designed the digital signal processing of the MU1, together with my colleague Pieter Meijer. This implementation took place in the past years, but the development actually started many years ago when we observed that CD oversampling filters were audibly degrading the signal quality. We found that the presence of a digital filter itself was not to blame, but the precision of its implementation. The digital processors inside DAC chips had and have very limited processing power, which restricts the maximum achievable sound quality. We decided to design our own filters and put them in an FPGA and then a long and interesting adventure started. It turned out that every single detail matters with digital brickwall filters, there are no short cuts. To get them right, an incredible precision is needed and a lot of creativity to find the best solutions. 

Looking back on the steps we took over the years, it strikes me how the playback gradually evolved from ‘reproduction’ to ‘presentation’. Reverb and other spatial aspects like coughs in the audience, creaky seats, noises etc, seem to disappear in the background and that’s a good thing. In stead of an audible reverb that seems to be part of the music itself, you get an almost visible space in which the instruments are placed. In stead of a relative superficial experience, your ears use the reverb information of the recording to experience a virtual three dimensional image that resembles navigating the real world. What started as gradual improvements of the playback turned into a whole new listening experience.” 

The MU1 team, from left to right: Peter van Willenswaard, Hans van Bommel, Michiel Schriever, Koen van Brero, Eelco Grimm, Justin Vis, Marco Schmidt, Rob Munnig-Schmidt, Pieter Meijer, Gertjan Groot Hulze, Guido Tent

Peter van Willenswaard

“My influence on the MU1 is in the background, I never even touched it as far as I can remember. You could say though that my spirit hovers over and through the MU1, as with all Grimm Audio products in fact.

I am specifically concerned with super silent power supply circuits wherever they are needed. I designed a very simple but effective shunt supply over 15 years ago and we still use it. These are really silent: less than 300 nV in the audio band.

And I am the jitter guardian: if there is a jitter problem, it’s my call.

My other support is that I stop by from time to time and ask nasty questions.

Of course these are just a few aspects. Over the years we have learned that everything, literally everything, matters if you want top quality audio. Down to the choice of even a single resistor or one tiny capacitor.

If you work hard, pay attention to every detail, and have a little luck, you end up with a smile on your face and on the face of your customers. Taking it too easy will damage the musicality of the equipment.”

Koen van Brero

“During the better part of last year, I had the opportunity to work with the dedicated engineers at Grimm Audio on this remarkable product. When Guido and Eelco asked me to assist them with defining the software architecture for the MU1, I jumped at the chance of using my knowledge about software architecture and design to make the MU1 work the best way we could.

Defining the software architecture was a two-part job. We needed to define both the architecture of the software running on the mini-computer inside the MU1, as well as the architecture for the custom Grimm Audio processing hardware, which is employed for attaining the highest level of audio quality.

“Sounds interesting…”, you may think, but what does “doing Software Architecture” entail? A good architecture should simplify things. Defining it is a quest for finding similarities in the many parts of the system and unifying them into similar structures and solutions. In essence, “doing Software Architecture” entails creating harmony.

This not only makes the system more easy to understand and therefore easier to build, but it also enables us to use it for multiple products. The MU1 that we show to you today is only the first in a line of audiophile and professional audio products that are going to be based on this MU-platform.

And on a lighter note… 

Where did this “quest for harmony” lead us to? What is the end result? The shortest possible answer I can give to that is: “12”.

The architecture is fitting for the 12 different use cases for the MU-platform we envision today. And “12” is a very nice number when it comes to creating “great things”. In popular culture, some believe that “42” is the answer to all questions. For architects, the right number seems to be “12”.

MU is short for MU-sic, and in western music, harmonies are created by using infinite combinations of 12 different ‘notes on a scale’. Together they form the 12 essential building blocks in the architecture of music. And playing music is the main reason why the MU1 “came into being” in the first place.

MU is also short for ‘muon’. Which in modern particle physics is believed to be one of the 12 elementary particles of the standard model that together form the 12 essential building blocks of all the matter in the known universe. For sure, the architecture of the MU-platform should adhere to this “Grand Architecture”.

But wait, what about the 13th particle, the Higgs-Boson or God-particle, discovered using the Large Hadron Collider at Cern a few years back? For us architects it has always been clear that this simply cannot be right. It should be 12 not 13. And indeed, the Higgs-Boson is deemed by more and more physicists to be a mere “quantized manifestation of the Higgs field” and not an elementary particle after all.

As can be seen, the number 12 is very important when it comes to architecture. And I wonder when I look at the architecture of language: Is it a mere coincidence that ‘MU’ is the 12th letter of the Greek alphabet?”

Guido Tent

“When I was young, I was surrounded by tons of components that I found in my fathers workshop. I did not have any clue about them and most of them had magical appearance. I built my first electronic circuit when I was 8 or 9. Later, I assembled my own stereo system which eventually led to setting up a drive-in discotheque, building huge speakers, light effects and so on. This was, and still is, my main connection between electronic engineering and music. I built my first tube amplifier when I was around 18 and that made me aware of sound quality, rather than sound pressure level. Mark that all those activities did not positively contribute to my school results.

Firing up your first circuit is major excitement: will it explode or not? Next, will they work, and still work tomorrow? After some experience the electronics world becomes predictable. Eventually this can lead to the EMI performance of the MU1 switch mode power supply where only 1 out of 100 million electrons escapes as electromagnetic radiation. And to clock circuits with jitter down to a few tens of femto seconds only. And shunt regulators with power supply rejection up to 140dB (yes, that is 10 million).

Developing true audio products is all about control. We are extremely happy to have gathered a team with that mentality in their DNA. Grimm Audio products are designed by talented engineers that have the mindset to control what they do, and never let go. The MU1 is the ultimate outcome of this mindset.

I would like all our team members to step forward and join me on stage.”

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