hat's going to be quite an atypical intro – I'm no fan of ESS Sabre DAC chips. These (different models I mean) are used nowadays by many manufacturers for both inexpensive and high-end devices, and many people consider them the best off-the-shelf chips manufactured today. I am not going to argue that at least when it come to technical specification. I don't have enough technical knowledge to do that so I tend to trust those who such a technical knowledge possess. But I don't see a reason not to discuss Sabre sonic qualities and so far it's seemed to me that there is a certain sound characteristic to all devices sporting these chips – an impressive, high quality sound that tends to weary me after short listening time. That's been simply not my cup of tea, at least until now. Yes, my Oppo player sport such a chip, but Dan Wright did a great job with his tube mode which made this player not only to sound great but to play music in a way I like it. Also, to be perfectly honest, I've found myself using Oppo mostly to play movies, not music.

Last year in Munich (during HighEnd Show) I had a chance to listen to already highly acclaimed new Auralic DAC called Vega (system included my favorite Audeze LCD 3). Vega used Sabre chips (obviously) and… I wasn't truly charmed by this system. Yes, these are open design cans so listening via them during show was not the best idea, so I realized I couldn't cross this DAC off just yet, but it wasn't game changing moment for me (I mean to start loving Sabre chips) either. I've been discussing Vega test with Polish distributor for some time but it kept getting postponed. In the meantime another company, a Canadian Resonessence Labs founded by Mark Mallinson (Resonessence Labs is a brand belonging to mother company called BCIC Designs Inc.) managed to create a lot of fuss on the market. Name of this guy might be known to ESS Sabre fans as he is a former Operations Director of that company. That means that he knows these chips like very few other people do. I guess it's clear what this company does – it manufacturers D/A converters of course using Sabre chips. Their portfolio includes for now for (or five depending on who's counting) products. It starts with Herus, a small, sleek DAC with asynchronous USB input and headphone output. Second device is called Concero, and there are two sub-models (that's why one could count four or five models). There is a HD version - a DAC with 2 inputs: USB and coax, with analogue RCA output, that might also be used ad USB converter with digital signal sent out via coaxial output. The HP version lacks analogue RCA output but instead sports a headphone output. And last but not least two top of the line devices, that show a lot of similarities: Invicta – D/A converter that accepts also DSD signal (64 and 128) with two headphone outputs and SD cards reader. The SD cards can be used to upgrade Invicta's firmware but also to play music stored on them (which makes it a file player with DAC and headphone amp in one box). The second device is called Mirus – the design is quite similar to Invicta. The main differences being lack of headphone outputs and the second ESS Sabre ES9018 chip that improves some technical parameters of the device.

As I already mentioned there was a lot of fuss about Resonessence Lab's devices on many audiophile forums including Polish ones, so I decided to make another attempt in my search of device with Sabre chip inside that I would not only appreciate but also like. I contacted Mark Mallinson asking for a review sample. He answered immediately with information that he was just finalizing an agreement with Polish distributor. Just a few days later I was contacted by Mr Piotr Chilecki, freshly appointed Resonessence Labs distributor for Poland offering to deliver Mirus for a review. As it so happened that the item I was supposed to review to our April's issue didn't come on time the Canadian DAC could take its place. It got even more interesting when on exactly the same day also the long awaited Auralic Vega came in for a review (for HiFiChoice). That gave me a chance not only to listen to two supposingly very interesting devices based on Sabre chips but also to compare them head to head.

Even before Mirus arrived to my home I received an information from Mr Piotr saying that he'd installed the newest beta version firmware on it. He also informed me that the official release of this firmware should be available in just 2-3 days together with the newer version of USB driver for Windows. He insisted that my critical audition should take place only after I install official release of firmware and newest driver as each new software released by Resonessence Labs improves not only functionality of their devices but also sound quality. The previous firmware, for example, added the DSD128 support, and compatibility with this small, simple Apple remote control (that I received together with device for this review). The newest firmware, that I actually received from Mr Piotr just a day later, today (March, 29th) still isn't available on the website so I don't really know what new it has to offer. To give you a better inside into this Canadian company and their product's let me quote a email I receive from Polish distributor:

Attached you'll find a few pictures showing different stages of Mirus' enclosure production – you can see how meticulously these are made using CNC machinery. An important thing about Resonessence products (considering that still most audio products are made in China) is the information that they are all made „in house" in Canada. That is quite a rare approach especially considering that that prices of their devices are quite reasonable unlike many other high-end devices. The retail price for Mirus on our market is 17 000 PLN, which just about 10% more than it costs on American market (and we have to remember cost of transport, plus customs fees and VAT).
A few words about company – it's founders are Mark Mallinson - a former Operations Director at ESS Technology, his brother Martin, who still is a chief engineer at ESS Technology, and a creator of (among other things) Hyperstream technology, and a third man, who designed some units that were part of ESS Sabre processor. It is a well know fact that implementation of ESS Sabre chips is quite challenging so not all the companies using them are able to make most of its capabilities. Considering who the people behind Resonessence Labs are I dare to claim that if anyone was to succeed it was surely them.
The Resonessence engineers keep working on software development for their devices all the time which is possible thanks to their smart internal architecture which, for example, makes it possible to use one of BNC sockets for communication with external Word Clock, or to use HDMI port as "Audio IN", which after connecting to it e.g. Oppo player turns Mirus into a streamer (not only for PCM files but also for DSD128). Mirus sports also some other unique features – it is able to receive DSD signal over Toslink, SPDIF and AES/EBU inputs, it internally converts PCM signal to DSD (a la Meitner), it's equipped with several user selectable digital filters, and it supports most file formats, also when played from SD card.

It seems that the Canadian Resonessence Labs follows the same path as growing number of American manufacturers (like ModWright, Schiit Audio and others), that manufacture everything either in-house, or at least use suppliers from their own country, and despite that still try to maintain reasonable pricing. Resonessence Labs guys keep in mind that customers expect high quality fit&finish and reasonable pricing combined with abundance of features, like large variety of digital inputs, support of all sorts of files including hi-res ones and DSD that despite limited availability (of music in this format) seems to be a must for every new D/A converter. Mirus and Invicta are currently top-of-the-line products and both are priced just shy of 5 kUSD (this prices proves that despite all significant additional costs that Polish distributor has to cover Polish price is in fact reasonable). Obviously such a price doesn't really allow me to call them inexpensive but unlike many other D/A converters on the market costing dozens of thousands USD these one are surely priced reasonably especially considering large number of features and extremely good fit&finish (not to mention the sound).

Before I received my review sample I've never seen this device, I mean except some pictures of it – I have to admit that whoever took those picture really knew what he/she was doing. Because after seeing these pictures I imagined quite a large device, however in fact it is not much bigger than my TeddyDAC, or Hegel HD11 – the front is just 22 cm wide. When you look at Mirus the eye is caught right away with a very nice looking OLED display. Despite its size one can easily read all information on it, at least from up close as from a larger distance only the digits showing volume level are large enough to see. The are 10 levels of brightness of the display which makes it easy to adjust to one's personal needs. Below the display there are four function push-buttons, on the right side two rows of blue LEDs indicating the sample frequency of played signal (when DSD is played two LEDs are on at the same time). Below there is a SD card reader slot, and a multifunction knob, that allows user to control volume (this DAC sports outputs with adjustable signal level) and move around the menu of the device. This sharp, blue OLED display and a back-lit logo (blue when on, red when in stand-by) give Mirus a very nice glare, especially in the dark room. A very good news for those who, like me, hate all those eye-hurting bright LEDs that manufacturers put nowadays in most devices, even the brightness of the LED behind logo can be adjusted so that it feels comfortable to look at the device when listening to the music even in a dark room. A small detail? Perhaps but really annoying and Resonnessence offered a simple solution – way to go! That earned Mirus a lot of points in my eyes even before I started a serious audition.

Menu of the device might seem complex by moving around it is quite intuitive. Mr Piotr send me a detailed instruction of the whole process of upgrading firmware but it was was simple that I might do just fine without it. Also installation of a USB driver went on my WIN 8.1 64-bit PC flawlessly, which is not a rule (often there are some sorts of problem with USB drivers on this system). User gets 5 digital inputs at his disposal: 2x BNC, 1x AES/EBU, 1xToslink, 1xUSB, plus a bonus – he can play music from SD card which means that this device doesn't require an external source of signal. Some user might miss a classic coaxial input. The second Toslink socket you'll find at the back of the device is actually a digital output, the third BNC is not used although it might be used to connect an external Word Clock.
There is also a HDMI port – for now it is used as video-out, allowing user to connect it to a some sort of display (computer monitor, flat screen and so on) which will allow to display, for example, a content of SD card. One of future firmwares is supposed to add another feature to it – it will be possible to used it as Audio-in port and to connect, for example, and Oppo player to it. This might be really interesting judging from my experience from Devialet review that also sported HDMI Audio-in port and I loved the sonic result when I played music from Oppo via this connection.
As for analogue outputs there are both balanced (XLR) and unbalanced (RCA) ones. Using Apple remote with Mirus wasn't so intuitive from my point of view but I'm sure that with some practice it would come really handy. The reviewed device supports different PCM files (WAV, FLAC, AIFF), also hi-res up to 24/384, and also DSF and DFF files (in both DSD64 and 128). There are 7 user selectable digital filters, that might be switched during playback making it easier to chose the preferred one (there is a short break in playback though when switch is made).

I started my listening session with music stored on SD card – simply because distributor sent a 64GB card together with the device. There was some music on it including hi-res FLAC files and DSD files. Truth to be told – it was also very easy – I had to plug the power cord in, connect it with preamplifier and that was it – no configuration, no driver installation (at this point I didn't know it would be flawless). As I'm not a fan of digital volume control I decided not to used it. There is no way to turn it off, so I just dialed the scale up to 0 dB (max volume). Anyway volume control might be useful if you want to connect DAC directly to power amplifier, but again, since I don't like digital volume control I decided to ship that option or to test it at the very end of this test if there would be some time left. Well... after all I simply forgot to check it out... Sorry. I added some recordings to the card and started my first session (already using newest firmware and USB driver). It was supposed to be a short one as Mr Piotr claimed that while sound quality when using SD card was very good but when using USB input it was supposed to be even better. But I liked what I heard so much that for the first three days I kept giving Mr Piotr the same answer: „I'm still listening from SD, will start with USB tomorrow”. It was a really smooth, liquid sound, rich with details, open, transparent, saturated and musicality was its asset too.

Sabre based device usually seem to sound bright to my ears. I used „seem to” expression on purpose because it's not really about brightness. They usually offer sound that is so rich with details, so transparent that these two elements dominate all other aspects of sound, they force listener to focus on them which makes music sound lean. For my taste midrange is never rich, colorful enough – it's too „cold”. Usually – but not this time. Both range extremes were nicely extended, bass was fast, taut, maybe lacked a bit of a punch, but still dynamic and rhythmically involving, the treble shined with details, breathed, was beautifully lively and vibrant. But these damn good range extremes didn't overwhelm the most important part of the range – midrange. It was smooth, rich, colorful and nicely palpable. Finally I found a Sabre based device that sounded to my liking! This wasn't just a great sound that lost its touch with the essence of music anymore – this was a complete presentation!

My evening sessions I conducted with my wonderful Audeze LCD3 driven by amazing Sugden Masterclass HA-4. The American cans driven by British, class A amp offer delightful presentation that never stops to amaze me with its smoothness, richness and density of the sound. Using Mirus as a source enhanced the sound of this system with even more details and with (that's not my description, but a very good one) an „ear-friendly transparency”, plus impressive dynamics which turned out to be a perfect match. Individual features of all elements of the system complemented each other – LCD-3 offer powerful, extended, punchy and yet very well defined bass, a sound with absolutely no brightness of any sort to it but extremely reach with details and subtleties as far as the source is able to deliver them. In this system they are supported with amazing class A Sugden headphone amp, that enriches the sound, gives it more „weight” and does a wonderful work when it comes to presenting timbre and texture of voices and instruments. When I added what Mirus had to offer on top of all that the outcome was breathtaking, musically involving and it kept me up for hours until very, very late every evening.

Finally I had to start exploring other options – or in other words use my AudioPC as a source. I did it in two ways – I used my reference Bada Alpha USB converter that was connected to AES/EBU input of Mirus, and connected USB output of my PC directly to USB input of reviewed device. As I mentioned before I received also the Auralic Vega for a review at the same time that came with JCAT USB cable. I liked it a lot so I decided to use it also when listening to Mirus. Installing Resonessence Labs new USB driver went flawlessly on my WIN 8.1 64-bit machine (didn't have any trouble with VEGA driver either) and DAC was recognized by computer immediately. For less advanced users Resonessence Labs prepared a detailed instruction explaining clearly how to configure most popular software players for Windows and MAC OS. So even if you're not a computer geek don't worry – just follow instructions and you'll find using Mirus with your computer quite simple. Mr Piotr suggested that properly configured computer was even better source than SD card offering even better performance. Right after I started my first session with PC as a source I had to admit that mostly in terms of resolution and selectivity improvement was quite obvious, and, to some point, also in terms of dynamics.

I started with large scale symphonic music which gave me a very nice inside into the sound features mentioned above. I hope you don't mind another digression considering my previous experience with Sabre based devices. When it came to playing symphonic music they usually offered very good selectivity and imaging. Also an abundance of details thrown at me was impressive. The point was that all these elements were so distinct, they attracted my attention so much that each time I lost the „big picture”, or the music itself from my sight. That's a good thing if you want to analyze smallest details of the presentation but not so good if you want to enjoy the music.
This time it was different – what a relieve! All the elements came together to create a coherent, beautiful music presentation. I love a large scale soundstage with all elements firmly shown in their places, also great selectivity that allowed to follow any and every instrument or group of instruments but did it in a natural „non-imposing” way. I like a lot the way Mirus relayed a great dynamic scale of an orchestra and huge dynamics leaps. Plus there was this little, tiny element, the only thing that from my point of view was a must for every presentation regardless the price level of reviewed components if I was to like it – the emotional involvement in musical event, the trill of awaiting what would happen next even knowing particular piece of music by heart. That's what I'd miss so often when listening to Sabre based devices – lots of good sound but no music, no involvement, and that's what Mirus (and also Vega) finally gave me. Was it a perfect presentation than? Surely not. First of all there is no such thing, secondly much more expensive DACs prove that there is still some room for improvement in terms of resolution, smoothness, and in the bass area. Don't get me wrong – I truly enjoyed bass presentation, because I prefer well defined, fast, taut bass over one going deeper but losing its speed and without proper definition. You can have it both but that costs much more than 5 kUSD one has to pay for Mirus. So in fact the only moments I could complain a bit about Mirus performance happened when listening to large scale symphonic music and moments when I expected a really „heavy”, „weighty” sound of orchestra hitting me with its power and it didn't come with as much power as expected. But these were only brief moments followed by a wonderfully coherent, liquid sound of the most complex instrument of the all – the orchestra.

Another outstanding performance Mirus gave when playing acoustic music relaying beautifully the timbre and texture of each instrument. It took care not only about fast attack faze but also about sustain and wonderful, long decay, although Ardento's tube based PerfectDAC, that I still have at home for comparisons, proved that in this aspect there was still a small room for improvement. I already mentioned that I like Mirus' bass for being fast, taut, very well defined and all that worked really well when it came to playing Ray Brown's double bass, or well recorded drums. When listening to the latter I enjoyed how nicely different drums were differentiated, but also each time when a stick hit a drum (and a way it was hit was also nicely differentiated) and the membrane responded in a very firm, nimble way. Just to listen to that level of realism I listened to some recordings many times. I mentioned before that the bass delivered by Mirus lacked a bit of „weight” in the lowest area which suggested that one could miss something in the sound of such instrument as double bass. But I didn't. The texture, timbre, lots of details, subtleties that I could easily hear, the „agility” of this huge instrument in extremely skilled hand of Maestro – all that made this presentation so interesting, so involving that I didn't miss a thing. It was exciting to watch what this amazing musician could make his instrument play – that was the emotional trill I mentioned before.
I couldn't skip my favorite acoustic guitars in this test. No matter what recording I played there were always proper proportions between strings and „wood”, there was long decay, sound was fast and palpable. Presentation of *Friday Night in San Francisco** in terms of sound quality and musicality was dangerously close to what I knew from playing vinyl record on many good turntable setups, which means close to my personal reference (for this recording I mean).

Another important element of this presentation, making this D/A converter different than many competitors, was a huge, orderly soundstage with impressive width and depth. Comparing to somewhat more expensive (22 kPLN) tube D/A converter PerfectDAC, Mirus didn't render such a convincing 3D images as Polish DAC did, but there are really few devices I know (much more expensive ones I have to add) that could compete with Ardento when it comes to imaging. So it would be much more fair to compare Mirus to other solid-state designs and then it becomes a very competitive source, not only in terms of imaging but also in terms of precision, selectivity, resolution, and speed. 3D rendering that Mirus offered might not have been the best I knew but still the placement of each instrument on the stage, its size and weight seemed very accurate and that allowed Canadian DAC to create a very convincing, musical, soul touching experience.

A short test including Bada Alpha conducted maybe an hour before expected arrival of courier who was supposed to pick Mirus up confirmed what I'd already suspected (which also kept me from conducting this part of the test earlier). An owner of Mirus wouldn't have to bother himself with looking for any USB converter, not even such a fantastic one as Berkeley's. USB input implemented in Mirus is simply that good, comparable to what Bada Alpha has to offer in terms of sound quality, and having one clear advantage – it does accept DSD signal (64 and 128) which is an advantage if you're interested in listening to DSD material of course. I haven't really mentioned DSD so far. On one hand I like what DSD files have to offer in terms of sonic characteristic that in my ears is more “analogue” than PCM – I'd enjoyed listening to DSD files while reviewing Lumin, and I did like it now too. But since today availability of DSD files is rather scarce it seems to me that pushing ability to play such files for every device currently produced is more of a trend, maybe a temporary one, than something that could become a new audiophile standard, On the other hand – if you are to chose between a device capable of playing DSD and without such feature why not chose the former? Mirus is a device that offers excellent sound quality especially, but not only, via USB input even when playing a “regular” 16/44 files, not to mention highest quality hi-res PCM files like the HRX ones from Reference Recordings (24/176) that are a pure magic. If you buy it and have some recordings is DSD (most likely some samplers, or SACDs ripped using Play Station) you will most likely love the sound of these too. In my ears DSD files offer even more smooth sound than hi-res PCM file, which comes handy especially in acoustic and vocal recordings, but on the other hand when it come to rock music I prefer FLAC files that sound “sharper”, bit more “dirty” like a real rock music should.

Summary

After long listening sessions with Mirus (and Vega too) I have to admit I was wrong – Sabre based device is capable of playing not only a perfect sound but also a real, soul touching music. Why this particular D/A converter can do what others can't? Either it is a question of people behind this project, who know these chips inside out, and/or maybe these people are simply music lovers, sensitive enough to its beauty and for them the perfect measurements results just weren't enough. They needed not only to hear, but also to feel that music sounded right.
Mirus offers detailed, transparent sound with large soundstage, both left to right and front to back. It offers not only lively, extended range extremes but also rich, smooth, colorful midrange that is a must if almost any music is to sound right. There is one sound feature that makes Mirus quite unique – on one hand it seems to offer very neutral sound, on the other it is still warm enough to make vocals and acoustic instruments sound natural (as voices and acoustic instruments in nature never really sound cold). Despite its remarkable clarity and transparency Mirus never sounded lean, nor “technical”, which had made me dislike many other Sabre based devices before. Bass is fast, taut, rhythmic, very nicely defined, might not be that mighty, might not have such a powerful kick as some reference devices but it still damn good.
Mirus sports some features that its competitors don't – you can play files from SD card, and use it to upgrade device's firmware, and if it's your thing you can play 64 and 128 DSD files too. It's a D/A converter (that might be used as stand alone source when playing music from SD cards) that is build around ESS Sabre chips and convinced me (easily) that I could live with it happily ever after simply enjoying the music. Until recently I wouldn't believe that! There are not that many DACs at 10-20 kPLN price range on our market. There are a lot below 10 kPLN, and a lot much more expensive ones. So Mirus doesn't really have that many direct competitors and the only other device from this price range I know that could compete with Canadian device is Auralic Vega. It seems to me that even in 20-30 kPLN price range Mirus will not find too many worthy opponents, or at least ones that would offer big enough sound quality improvement to justify price difference. Congratulations to Mark Mallinson and other guys in Resonessence Labs are in place – gentlemen, you've created an outstanding product!

Mirus is, together with Invicta, a top-of-the-line digital to analogue converter made by Canadian company Resonessence Labs. It sports a relatively small, rigid, black metal casing. A central spot of the front of the device is occupied by a very nice, although not too big blue OLED display with adjustable brightness. In the upper left corner of the front there is a backlit logo, and the brightness of this LED can also be adjusted – a very nice feature. There are four black push button under the display that allow to use several functions. On the right side there are 8 blue LEDs indication sampling frequency of the signal currently processed by DAC. Mirus supports PCM signals from 44,1 to 384 kHz, and DSD signal, both 64 and 128 – when it receives one of the latter two blue LEDs are on at the same time. Below there is a SD card's reader slot. SD cards can be used for playing music, or to upgrade device's firmware (manufacturer keeps working on new sound quality enhancements and adding new features to Mirus and thus new firmwares become available every now and then). On the right hand side there is also a multipurpose knob. It is used to turn the device on/off (when you push it), to control volume and to move around menu. The top of the device sports lot of ventilation gaps that are needed as Mirus gets quite hot while working.

The back panel is divided into three parts – (starting from the right) a power section with IEC socket, main on/off button, and a fuse, a digital section (in the middle) with 3 BNC sockets (two are actually used now, third might be used in future to connect external Word Clock), HDMI port (today It serves as „Video Out” to connect a monitor or flat screen, but might be used as “Audio-in” in future to connect, for example, an Oppo player as a source of signal), USB port (asynchronous, Class 2.0), plus TOSLINK input and output. The third section, analogue one, sports RCA and XLR outputs.

Also the inside is divided into sections. In a separate shielding “cage” manufacturer placed two SMD board one above the other, each hosting a 32-bit, 8 channel ESS Sabre ES9018S chip. Doubling the number of chips seems to be, along with lack of headphone outputs, the main difference between Mirus and its twin – Invicta. Using two Sabre chips allowed, according to manufacturer, to achieve even better parameters, especially an impressive S/N ratio that reaches 133 dB. Mirus makes use of the digital volume control that is implemented into Sabre chips. Same section hold another small board with a precise Crystek clock. Power section includes quite large toroidal transformer and 12 smoothing capacitors with total capacitance of 26 400 μF. The digital signal is processed by FPGA Xilinx Spartan-6.

Specification (according to manufacturer)

Digital inputs: AES/EBU, BNC (x3), USB, Toslink
Outputs: RCA, XLR, HDMI, Toslink
THD: 0,0002%
Dynamic range RCA/XLR: 125/130 dB
Output signal RCA/XLR: 2,3/4,6 V
Supports: PCM 44 to 384 kHz/ 32 bit; DSD 64 and 128
Additional feature: SD card reader
Supported SD card file formats: WAV, AIFF, FLAC, DSF, DFF
Dimensions: 220x50x282 mm
Weight: 2,9 kg