Anyway, for those of us who try to stay away from hifi myths and are ready to accept (sometimes with some reservations of course) what technology presents us, there's joy and practicality to enjoy music at home. Don't misunderstand me, I'm not a techo-junkie. It's just a matter of evaluating without prejudice what is available at our service at the moment and still be critical enough to not accept every novelty as a magic step towards good sound.
It's been many years that I transfered all my music collection to computer environment. I have been using MPD on Linux as a source through an external DAC. It was a Musical Fidelity V-DAC at the beginning. In time, I had DACs from HRT, Musical Fidelity again, Teac, Cambridge Audio, iFi and Pioneer. It was easy for me to see the difference of new generations of DAC chips from different manufacturers and their adaptations in various models. It's a pleasure to see (or hear) how the sound of digital audio evolved in a short time of just some years.
My last choice of DAC for my system is the humble looking product of RME of Germany. I knew this brand as a producer of studio equipment. They had an ADC/DAC unit that was available for a few years that became a favourite of music producers and up to a level of some music lovers. But honestly, why should you spend your money for a devide that works both ways of converting music on a home hifi system when what you need is to convert from digital to analog only? It seems RME people understood the demand and decided to produce a product that does what you need for listening only. Still, they were reluctant to leave their roots as a supplier of studio devices and prefered to design a DAC that could be used both by hifi enthusiasts and by studio people who need to listen what they produce.
So comes the ADI-2 DAC FS. A small device with a strange name. This is not the first model of the range but a newer version of a previous model.
It's small, too small for a home hifi product unless your choice of listening is by headphones alone.
This is how ADI-2 DAC FS (new generation) looks like.
There's no internal power supply. An ordinary looking external switching supply is the power source for the unit. A jerky plug at the end of adapter cable fits into the input terminal on the back of the unit by pushing and turning to lock the plug. Once done it's OK but you are supposed to be very careful or read all the user's manual before even connecting the power cable.
There are all the digital inputs you expect on a contemporary DAC and both unbalanced RCA and balanced XLR analogue outputs on the back. Front side has two phones outputs. The second one is some novelty for in-ear monitors that require different output characteristics.
I use the unit to feed my integrated amplifier, so back side connections are my choice to hook up the unit in my line from source to speakers.
Once you operate the unit, you realise that this is not a mainstream DAC. Of course, those who start reading the exemplary user's manual will understand this before even turning the unit on. Yes, the user's manual is something I have been missing in all equipment I bought in the last 10 years minimum. It's a 72 pages booklet that try to explain all the features of this DAC with honesty. You have to understand from the beginning that this DAC is capable of a lot of tunings beyond converting bits into waveform.
As you can imagine, at first I just plugged in the DAC and run it as it is to see how it performs on factory set values.
My system is based on a laptop running MPD on Kubuntu as souce. RME DAC is in between the computer and a Marantz PM-11s3 integrated amplifier which feeds a pair of KEF R900 speakers. Most of my music collection consists of FLAC files of both standard and high resolution types and some are DSD files.
My first impressions of this DAC after listening to some jazz and classical music were absolutely positive. A smooth and detailed sound that was unlike any other DAC I used before. You immediately realise that this device is a technological marvel, nothing less.
After spending some time listening to music I knew, it was time to fine tune the DAC to use its full potential. It was at this moment I realised the negatives of the physical design of the unit. It's too small for what it's supposed to perform. There are four tiny push buttons you need to press that are lined up vertically and are just milimeters away from each other. Even the two rotary knobs on the far right side that also function as push buttons are so close to each other that you are unable to make a full turn since your fingers get stuck in between the knobs.
This is where the RME team compromised a hifi design for a studio equipment because as I understand, this box size is a rack standard on recording studios. For home use, it's ridiculous to squeeze all these buttons and knobs in such a small area. A DAC of similar size is Teac UD-301 but it has only two buttons and a volume control on it that are sparsely placed.
One additional negative point is the choice of feet for the unit. The DAC is very light weight and the push-in knobs require a decent presure to apply for the settings. You can guess the outcome. The ADI-2 always slips back on the desk whenever you press a knob. I had to stick elastic non-slip feet to make it stand still while I was making changes in the setup.
You can see the additional circular plastic non-slip paddings I used on all the four feet. It's beyond my understanding how the designers can overlook such a simple but obvious problem.
The biggest feature on the façade of the device is not knobs or connections but the LCD display that really makes a difference. There is a high level of information available to see what the unit is doing and to make changes according to your choice. Main screen has a precise spectrum analyser and VU meters. You already saw this screen in the two pictures above. More versions of main screen are available that concentrate on volume level and input signals but since I use the fixed output level in my setup, I'm not much interested at output level. However, be aware that this is not an ordinary DAC where you can choose the fixed or variable output level by a small switch at the back panel. You have to go into menus to select the fixed output level precisely to your taste or equipment feed and this is just the top of the iceberg. You can change so many settings that you need to arrange a position for yourself where you feel comfortable facing the RME DAC since you are supposed to spend some significant time tuning a variety of parameters of crazy detail and testing to see if it fits your taste. You might easily turn out to be a paranoiac trying to hear the differences during all those tunings. But after you feel like you finished your process and get away from the DAC to your listening position, you are rewarded with a magnificent sound. I spent almost three evenings for finishing up with all these crazy variables and now I can take a glass of wine to enjoy my music in the dimmed lights of my room.
An experienced DAC user might ask the plain question "There might be some choices of digital filters but what else?" Well, you have to read the user's manual to see what the else is!
Let's move to listening impresions. My FLAC files never sounded this smooth, enjoyable and solid before. A good recording really shines with this DAC. Mediocre ones are processed according to your choice but don't expect miracles.
I also listened to some DSD files to hear how my new DAC handles them. At first, RME didn't accept them as they are and MPD (music player daemon, my source software) converted them to PCM as it should do if the USB DAC connected is not able to play DSD. After reading again the related part in the manual I realised that RME accepts DoP protocol for DSD signal. I had to modify the configuration file of MPD to feed DoP bits to the DAC. There were no bad surprises, DSD was on the DAC to convert to analog signal. You can get this information clearly on the LCD panel as shown below.
Optical and Coaxial inputs are not connected and there's DSD signal on the USB input.
How does DSD sound? Well, it depends on the recording quality just as in FLAC. I'm not a big fan of DSD. It's very clear that when technical characteristics are objectively compared, there's nothing extra in DSD over hi-resolution PCM. But if I'm to evaluate the DAC alone, the sound of DSD is just as the sound of PCM: top class.
So, where are we at the end? This is an exceptionally well made product on the electronics side. I have absolutely nothing to complaint. On the physical/mechanical side, there is way to go. Why do we have to fiddle with these tiny buttons, awkwardly placed knobs, slippery feet on such a high quality (and not cheap!) DAC?
See RME ADI-2 DAC FS next to my Marantz amplifier below.
Even the connection cables look huge compared to the DAC itself. They are not some exotic ones costing more than the DAC itself, by the way. These are DIY cables I made using decent and reasonably priced parts.
Now comes the last words. This is a very enjoyable, talented, honest piece of high tech equipment. I sincerely wished to see it in a larger box that is easier and pleasant to control.
So, function over form, sound over physical design, this DAC really makes a difference.