Invicta MirusReviewers' ChoiceCanada’s Resonessence Labs made a name for itself with its first product, the Invicta DAC ($4995 USD; $3995 at time of review), which our own S. Andrea Sundaram positively reviewed in July 2012 for SoundStage! Hi-Fi. Since then the company has primarily been occupied with releasing a host of new, less expensive products -- their Concero line -- priced below $1000 each. And just this past year, Resonessence reached an even more attractive price point with the Herus USB DAC-headphone amplifier, for $350. Reaching a wider audience is clearly one of the company’s goals, and I think it’s a strong move -- many audiophiles are realizing that great sound needn’t cost an arm and a leg.

After launching all of those more-affordable products, Resonessence decided to revisit their flagship DAC. They’ve now added a second Invicta model, which is the subject of this review: the Invicta Mirus ($4995). If you’ve read about the Invicta, you already know a lot about the Invicta Mirus. Many of the original model’s features are carried over, but a few of the modifications might make the Mirus more suitable for some systems. Mainly, the Mirus does away with the Invicta’s headphone module to make room for a second ESS Sabre ES9018 DAC chip, to increase the THD+N specification to a claimed -114dB and the dynamic range to more than 130dB. Basically, if you don’t need or want the original Invicta’s headphone jack, you’ll want the Mirus -- it’s designed to maximize the sound of a conventional audio system with two loudspeakers. The Invicta Mirus is compatible with all commercially available sample rates up to 384kHz, and will accept DSD64 and DSD128. Basically, it will play anything you feed it.

The front panel of the Mirus offers the user lots of useful adjustments and information. On the far right is the rotary volume control, and just to its left are the sample-rate indicators: 44.1, 48, 88.2, 96, 176.4, 192, 352.8, 384kHz, and DSD. Right below these is a slot for playing music directly from an SD card. To the left of the sample-rate indicators is the main OLED display, which indicates the input being used (e.g., “USB Audio”) and the volume level selected. Below the display are four pushbuttons. The far-right button lets you scroll through the digital filters (explained below) as you listen. Pushing the button on the far left brings up a list of sources, from which you select by turning the volume knob. That done, pushing the volume knob locks the Mirus to that input. The two middle pushbuttons at first seemed inoperable, but are actually Fast Forward/Next and Rewind/Previous, to be used when navigating the file directory of an SD card, viewable by connecting the Mirus’s HDMI output to your TV (and on the OLED).

On the rear panel, from left to right, are XLR and RCA analog outputs and digital inputs, including AES/EBU (XLR), TosLink, USB, and two S/PDIF (BNC). There are TosLink and HDMI outputs, a master power rocker switch, and an IEC connector for your favorite power cable.

Invicta Mirus

User settings are most comprehensive. You can program the Mirus to default to a specific source and at a specific volume level, so that you’re ready to go on power-up. A maximum volume level can be set so that spouses and kids don’t inadvertently blow up your speakers when fiddling with the system. You can set the brightness levels of the display and LEDs. The phase of the right and left channels can be individually inverted. Because the Mirus has a digital volume control, you can bypass an analog preamplifier if the Resonessence is part of an exclusively digital system. If you do have an analog preamp, Resonessence instructs you to set the Mirus’s volume level to -30dB and adjust it up or down from there to match your preamp’s gain structure. I found that setting the Mirus to -15dB gave me the most usable range with the Ayre Acoustics KX-R and KX-R Twenty preamplifiers. I also used the Mirus’s volume control straight into Ayre’s MX-R mono amplifiers and found it to be very transparent. Still, the sound was a touch more dynamic and authoritative with the Ayres between the Invicta Mirus and the MX-Rs, so that’s how I did most of my listening.

There’s been a lot written about the many digital filters used in various DACs. Depending on your personality, the Mirus’s many options will either drive you crazy as you try to pick which one to listen to, or make you feel you have all the bases covered. The choices are: Fast Roll Off, Slow Roll Off, Minimum Phase IIR, Minimum Phase Slow Roll Off, Linear Phase Apodizing, Linear Phase Fast Roll Off, and Linear Phase Slow Roll Off. It would be easy to describe the Mirus’s sound with each of these filters engaged, but such a review would not only quickly become convoluted, it would also make it impossible to peg the sound of the Mirus in general. So I defaulted to the Linear Phase Apodizing filter, which Resonessence says is the “preferred filter of many of our beta testers.”

The Invicta Mirus comes standard with an Apple IR remote control of machined aluminum that matches Apple’s latest laptop models. With this you can adjust the volume and change sources, among other things. This little remote’s very high quality is completely in line with the quality of the Mirus itself. Though not extravagantly built, the Mirus is certainly solid. Its case measures 8.66"W x 1.97"H x 11.1"D, and its bottom plate is a solid piece of milled aluminum with a fitted aluminum top/side piece that makes the Mirus feel like a little brick. I experienced zero operational problems during my time with the Mirus.

Before doing any listening, I asked Mark Mallinson of Resonessence Labs a few questions about the Mirus. Mallinson used to work for ESS, where his group was responsible for the development of the now-ubiquitous Sabre DAC. When I asked how Resonessence’s implementation of the Sabre might differ from other companies’, he deferred to the Mirus’s lead design engineer, who said, “The implementation that we use employs ultra-low-noise regulation for the analog references of the Sabre DAC. It’s so low that we typically get 130dB DNR at the output of the XLR connectors. We also have completely isolated the analog section from the digital section using these [Analog Devices] chips. Having the Sabre DAC chips at its core (there are two Sabre 9018s in [the] Mirus) and fully understanding how these chips operate [are] very important. However, what is really important in our design is not the particular DAC chip used, but everything around the chip. . . . [B]ottom line is that we made sure that the surrounding circuits have all the details worked out to allow us to get the ultra-low noise and THD.” By now everyone knows that jitter is a major contributor to poor-quality digital sound. When I asked what Resonessence has done to reduce this bugaboo, I was told, “The jitter rejection is twofold: First stage is Resonessence Labs’ proprietary technology built into the Xilinx FPGA, and this is where the bulk of the jitter rejection takes place. Second is the one employed in the Sabre DAC itself.”

There’s more to say about the Mirus’s features and design, but I see I’ve already exceeded my usual allotment of words for the description. Those who want more technical information about the Mirus should peruse the Resonessence website -- it’s chock-full. For me, it’s time to get to the . . .


Invicta Mirus remote controlLately, I’ve been a little hesitant to change my system much. Although I think audiophiles instinctively always seek better sound, I’ve been quite content with the sound of my present system: Magico Q7 loudspeakers, Ayre Acoustics MX-R mono amplifiers and KX-R Twenty preamplifier, Calyx Audio Femto DAC, and, for the last few months, an Aurender X100L music server. This combo fits my model of how an ultra-high-end system should sound: ultra-revealing, yet smooth and nonfatiguing; full-range, yet natural and relaxing to listen to; transparent to the source, yet not so ultracritical that I can’t listen to Pandora. In short, it’s the best sound I’ve ever had in my listening room, aka the Music Vault.

But, alas, I’m not only an audiophile, I’m an audio reviewer -- a constantly changing sound system is part of my life. Plus, for some time now I’ve wanted to hear a Resonessence DAC in my system.

Removing the Calyx Femto and inserting the Invicta Mirus could not have been simpler. I used balanced XLR interconnects to link the Mirus to the Ayre KX-Rs, and USB to connect the Mirus to the Aurender (and, later, to my MacBook computer). When I make a change in my system, I do things a little differently from what, I hear, many audiophiles do. Some guys want a piece of gear to warm up thoroughly, “cooking” in the system while they just listen casually. The problem with this is that it also lets your ears acclimate to the new sound. Instead, I listen critically from the very first note, when my ears are more apt to hear any changes wrought by the new component. Often, those observations made in the first few hours of listening prove to be most crucial.

The Calyx Femto ($5850) is a fantastic piece of gear, and one of the most transparent DACs I’ve had in my system -- ultra-revealing, it can uncover scads of detail in recordings of all types. So I was surprised that the Mirus never took a backseat to it in terms of detail retrieval. Right from the beginning, I could pick out all the little details with the same clarity that I hear from the Femto. I first played organist Mary Preston’s Crown Imperial, with Jerry Junkin conducting the Dallas Wind Symphony (24-bit/176.4kHz WAV, Reference HRx-112). It sounded crisp and alive, the bells and cymbals in the title track (by Sir William Walton) jewel-like in their precision. Even at very low volume levels, the Mirus was able to reveal the pristine little subtleties, such as the shimmer of the cymbals, that make listening to this music in hi-rez the only way to really hear it.

It would be no exaggeration to say that the Mirus was as good at detail retrieval as any DAC I’ve heard in my system. Microdetail was superb, but so were macrodynamics. When the drum whacks enter at 5:23 into Coronation March (“Crown Imperial”), the bass resonated powerfully through my room, rolling right past my listening seat. Though the Mirus is physically small, its sound was anything but -- it was as firm and resolute as I could ask for. When a component can unravel the tiny details that some components obscure, as well as faithfully reproduce any bombastic elements in a recording, I know I’m off to a good start.

Then I began to hear some things that surprised me. Listening to Neil Young’s Live at Massey Hall 1971, I compared the CD version to the 24/96 version from the DVD (CD/DVD, Reprise 093624332725), listening first through the Calyx Audio Femto. I heard a distinct improvement when I switched to the higher-resolution version: better image density, and a more rock-solid rendering of each note within the acoustic of Toronto’s 2765-seat Massey Hall. Through the Mirus, the same comparison sounded a little different. The superiority of the hi-rez version was still evident, but this time I heard an even more convincing reproduction of space -- specifically, more precise ambient cues -- that made it abundantly clear that I was listening to a live recording.

Invicta Mirus

Of course this led me to pull out more recordings that might reveal more about the Mirus’s rendering of space. “Club Descarga,” from Chesky Records’ The Ultimate Demonstration Disc, Volume 2 (24/96 AIFF, Chesky/HDtracks), was enlightening. The percussion’s reverberation gave clues to the precise locations of the performers in the room. The rhythmic nature of this music was on full display as David Chesky’s group swings and sways, congas and bass interweaving with bass clarinet, trumpet, and piano in a jam session I could relax into, thanks in part to the Mirus’s ability to faithfully paint the soundscape. By comparison, most DACs sound more two-dimensional.

The Invicta Mirus had no real downsides. It’s a fabulous DAC. It was extended at both frequency extremes, but in my system it never sounded harsh up top or plodding down low. It was ultra-revealing in the best sense, but was quite enjoyable to listen to with any music. I listened to a lot of Pandora, with my MacBook upsampling the feed to 16/44.1 before sending it on to the Mirus. Yes, the soundstage collapsed to a great degree, lacking the spatial cues and the clearly rendered extension at the frequency extremes. Nonetheless, I could still enjoy Taylor Swift’s cheesy “You Belong With Me” and Lorde’s catchy “Team” as background music just fine. “Let Her Go,” by Passenger, center-imaged like a champ, its simple arrangement sounding better than it had any right to, given the limitations of the source signal. The voices sounded spookily real, making this background music capture my attention long enough for me to take the center listening seat, close my eyes, and just listen.


You might come away from this review thinking that I feel that the Resonessence Labs Invicta Mirus DAC is very near perfect. I’m not sure I can say that. What I can say is that DAC technology is now at an all-time high, with fantastic products available for just a few hundred dollars to many thousands. I think the $5000 price point is a sweet spot for DACs these days, with state-of-the-art sound available long before you hit five figures. While I can’t guarantee that the Invicta Mirus will trounce DACs costing multiples of its price, I’ve not heard anything in my system, or at a show or dealer, that would lead me to believe that it’s not at least fully competitive with anything, at any price, on the market today. As I listened to it in my system, the sound wanted for nothing -- and I was mesmerized by how the Mirus was able to fully reveal the spatial qualities of live recordings. Unless you’re the type of audiophile who needs a huge, gleaming chassis in your system -- or several of them -- look no further than this little puppy for all your digital needs. Regardless of the pedigree of the rest of your gear, the Resonessence Invicta Mirus will fit in just fine.

. . . Jeff Fritz

Associated Equipment

  • Speakers -- Magico Q7 and S1, Sonus Faber Venere 3.0
  • Amplifiers -- Ayre Acoustics MX-R monoblocks
  • Preamplifiers -- Ayre Acoustics KX-R and KX-R Twenty
  • Sources -- Apple MacBook running OS X Snow Leopard, iTunes, Amarra 2.4.1, Audirvana; Calyx Audio Femto DAC; Aurender X100L music server
  • Cables -- Nordost Valhalla interconnects, speaker cables, power cables; AudioQuest Meteor speaker cables, Niagara interconnects, Carbon USB cable; Siltech Explorer speaker cables, interconnects, power cords

Resonessence Labs Invicta Mirus Digital-to-Analog Converter
Price: $4995 USD.
Warranty: Three years parts and labor.

Resonessence Labs
863 Coronado Crescent
Kelowna, British Columbia V1W 2K3
Phone: (778) 477-5536