Resonessence Labs Invicta DAC
Input: Asynchronous USB, (2) BNC, AES/EBU, Toslink, SD Card reader (supports AIFF and WAV files on SD and SDHC cards)
Output: (1) pair RCA line level pre-outputs (controlled by volume) (1) pair XLR pre-outputs (controlled by volume), Toslink, HDMI video output. (2) headphone out
Dimensions (W x H x D): 22.0cm x 5.0cm x 11.10cm (8.66" x 1.97" x 11.10")
Weight: 2.9kg (6.4 lbs)
User Manual: download
Availability: Direct and through Authorized Dealers
Warranty: "We warranty the Invicta hardware to be free from defects in workmanship and materials for three years." Details
The Invicta DAC is the first product from Resonessence Labs. The main man behind Resonnessence is Mark Mallinson, former Operations Director for ESS Technology and if you know about ESS Technology you'll know they make, among other things, the line of ESS Sabre DACs that you find inside a number of DACs from companies including Peachtree Audio, Weiss, Wavelength Audio, Wyred 4 Sound, Mytek Digital and many more. And now you can also find them inside the Resonessence Labs Invicta.
I don't think it's necessarily a stretch to suggest that people who worked on designing and developing a DAC chip would know pretty much everything there is to know about how that chip works as well as any strengths and weaknesses it may posses. On the other hand, I do think its a stretch to suggest that any DAC built with a specific chip is necessarily "the best" simply because it uses that chip. If you prefer an analogy, you can give Anthony Bourdain and I the exact same ingredients to make a meal and I know where I'd eat (hint: not my house). Yes, even if I know more about one of the ingredients. But to get back to what I consider the germane point, a number of the people responsible for the ESS Sabre chips are also responsible for the Invicta DAC.
What Makes Invicta Tick?
Let's start out by pointing out three unusual features of the Invicta DAC—a front-mounted SD Card reader and a rear-mounted HDMI output. These two are in fact related in that you can play music from an SD card (WAV or FLAC format on SD and SDHC cards), and you navigate its contents through the front panel display or on a big-ass monitor (actually the size is up to you. I was just having fun) connected to the Invicta via an HDMI cable.
And the third? From the Invicta User Guide which I highly recommend reading under the "Digital Input" section, "Invicta accepts only uncompressed stereo data and mutes in the presence of compressed data." It mutes in the presence of compressed data! My first reaction was wow, good for you! But then I tried playing some compressed music via Toslink and it...played. It turns out this restriction is limited to the SD Card reader which will in fact refuse to play compressed music even if you ask nicely.
I should mention that some parts of the Invicta User Guide are out of date. For example the section that describes how to go about Firmware Updates begins with, "1. Connect the power cord to the unit and a USB cable to the MSWindows computer." Mac users do what? Firmware updates are now handled through the SD Card—download the update to your PC or Mac, copy it to the SD Card and "play" it on the Invitca. Mark Mailinson not only offered this correction but assured me that updates are forthcoming.
In terms of inputs we're looking at a "proprietary" Asynchronous USB interface (the USB receiver chip is from Cypress Semiconductor), (2) S/PDIF BNC, AES/EBU and Toslink all capable of handling up to 24-bit/192kHz data. There's another BNC input which is currently reserved for future use. Another aspect of the Invicta design that's worth noting is that Async USB input auto-detects what its connected to. If the answer it gets back is a Mac, the Invicta defaults to outputting USB 2.0 (supports up to 24/192). If the answer is PC, it defaults to USB 1.0 (supports up to 24/96) unless and until you install the included custom Thesycon USB Audio 2.0 Driver for Windows. I'd imagine the idea here is for those users who don't want to mess with installing drivers, the Invicta is plug and play and if the day ever comes when Microsoft decides to join the 21st Century, the Invicta is ready and waiting.
Another feature and option that some may find worth exploring is those two BNC inputs can be reprogrammed as outputs or for "Word Sync, Clock and Data" if you'd like to use an external Word Clock. And the HDMI connector "is also there for a future upgrade, at the hardware level it can do any of these features: I2S over HDMI, HD OSD output, even ultimately HDMI Audio input. Currently it does none of these, because our software team have not yet completed firmware/software for these features to our satisfaction." Resonessence also encourages users to send in requests for additional functionality.
Outputs include pairs of balanced XLRs, single-ended RCAs and a single S/PDIF Toslink that outputs the SD Card or USB inputs in digital format. There are also not one but two headphone jacks around front with individual "trim level" controls meaning you can adjust the level down from the main volume setting to match the sensitivity of your cans and you can save these levels in the User Settings. To set headphone input levels, depress the associated button above the headphone jack and spin the volume knob. Nice and easy and perhaps the perfect solution for headphone loving lovers. A couple that listens together listens together.
The front panel OLED display shows you the output level (0.0 to -127.5db), input source, source selection option menu, and user settings. User settings include left and right channel phase, startup source, startup volume level for the XLR outputs, headphone A and B offset, max volume level, OLED and LED brightness levels, USB speed setting, and oversampling filter type. This last option allows you to choose between a fast or slow roll off filter and I'd recommend using the one you like listening to best.
There are also a series of blue LEDs on the right side illuminating the associated incoming sample rate. And now's as good a time as any to mention the build quality of the Invicta DAC which I find to be fairly exceptional especially in a tactile way. It feels good to use. Obvious care (and expense) went into the industrial design and I use that term to highlight design that conforms to function as opposed to design that conforms to fashion. Of course this also falls into the highly subjective arena of taste in terms of how much you cozy up to the looks of the Invicta. I find it inviting with a "use me" kinda vibe. Something I did not use but you could since its available—you can control the USB input's track selection (play/pause, fast forward/next, rewind/back) with the front panel controls or the remote. I preferred Apple's free Remote app for the iPad.
Back to more binary matters, the DAC in the output stage is the ESS Sabre ES9018 (in quad mode), while the headphones get their own dedicated ES9016 DAC. But what about the outgoing sample rate? I'm glad you asked! From the Invicta website:
The Invicta DAC brings all source content from its native sampling rate up to the 50MHz domain. This step is completed in the Sabre32 chip.Megahertz. And the reason for this relatively stratospheric level? I like to think of upsampling as a pasture; the higher the same rate, the more room to separate the good from the bad. But I tend to oversimplify so I asked Resonessence Labs President Mark Mallinson to explain. Here's what he had to say (I thought it worth including the entire response):
The Invicta uses the Sabre DAC (in fact there are two Sabre DAC chips in each Invicta unit) and the Sabre DAC takes care of the oversampling. The question of oversampling is a legitimate and meaningful one since audiophiles have correctly concluded that processes of oversampling can often introduce a perceptible degradation. Oversampling can be simplistic and not mathematically sound, although such a simple failing is rare in modern DSP processing. But oversampling generally implies an effort on the DAC designer’s part to improve performance by questionable means - by moving noise out of band and perhaps by "noise shaping".While we're hanging out in tech-ville, let's cover another aspect of the Invicta's design—galvanic isolation. From the Resonessence website, "Galvanic isolation is more than just separate [power] supplies: it is separate grounds as well, and it prevents any unwanted current flow causing a ground drop. Signals pass over specific isolation devices between these galvanic domains and noise in one domain simply cannot affect another domain because the return current is in the domain where the noise is generated." The USB cable's power is also galvanically isolated from the system and audio power supplies. If you prefer, think of galvanic isolation as a grazing pasture where you want to keep the water supply separate from the waste runoff otherwise you end up with crappy tasting water.
The audio community is rightly suspicious of oversampling (i.e note-NOS DACs. NOS means Non-OverSampling). Such oversampling DACs can sound worse despite measuring very well in conventional lab tests. But it is not the oversampling as such (at least when oversampling is done mathematically accurately to a very low noise floor), rather it is the dynamics of the noise shaping loop that the audiophile can hear. [It is the non-periodic steady state dynamics that cause the problem - refer to various presentations by ESS technical staff for more details].
The Sabre DAC is unique in that the designers have addressed (and solved) the issue of disturbing non-periodic-steady state noise in the loop. There are a number of patents of ESS in this area - search for all ESS Technology Patents from the Kelowna design center of ESS to find them. Given the absence of non-periodic-steady state noise, is oversampling itself a bad thing?
The answer is no, in fact it is an essential aspect of any high performance DAC. Without oversampling, the filtering of the alias signals present in the music content (there is utterly no way that aliases are not present in digital data - it is a mathematical necessity) has to be done by analog components. And as amazingly well done as analog filters can be, they still cannot come close to a precision digital filter on the oversampled data stream. Remarkably perhaps, it is also a mathematical necessity that even an oversampled data stream has aliases in it.
It works like this: a 44.1khz signal has spurious and unwanted alias signals in the "upper half" - that is from 22.05k up to 44.1k. Any desired signal in the 0 to 20k band carries with it an undesired signal "mirrored" in the 44.1k down to 24.1k band. Sony and Philips, the pioneers in the digital music field knew this, and still put the potential 24.1k alias very close to the maximum 20khz signal. They had to do this to make sure that the digital medium (CD's) could record enough time to hold a vinyl album. This has been a difficulty for all future digital music: in the Sony/Philips proposal a complex analog filter did its best to let through 20k and suppress 24.1k, but you can see that this is not easy! (20k is much too close to 24k). This is where oversampling comes to the aid of the modern audio designer: a good digital oversampling filter can really get in there and let 20k through while pushing 24.1k down to say -110db. Such a filter is present in the Sabre DAC.
But I mentioned that even an oversampled data stream has aliases in it - what about that? The aliases are as in the 44.1k case: the aliases are all counted downward from the sample rate as far as the audio bandwidth. For example, if a 44.1k signal is oversampled to say 176.4k (4x) then aliases are present in the 176.4k down to 156.4k, (176.4k - 20k) even if the oversampling filter is perfect. But you can see that the analog filter is now easier: it must now let through 20k and suppress 156.4k and higher.
The Sabre DAC does more: it samples into the 50Mhz clock domain! Now the alias is from 49.98Mhz to 50Mhz and the analog filter is required to let through 20k and suppress 49Mhz - this is very straight forward and no phase distortion, level imperfection or noise is introduced by such an analog filter: it can be very precise and very simple of the first or second order type (Sony/Philips mandated a 7th order analog filter!). In fact we need to add a little more: the above discussion explained the oversampling from 44.1k to 50Mhz, but of course, modern digital data is sampled up to 192k (or even 384k) and has far more than just 0 - 20k in the audio content: 384Ks/s could capture almost 200k of audio information. You can see that because the Sabre DAC oversamples to a surprising 50MS/s that it can easily handle even 100k (192ks/s) or higher.
The Invicta electronics is well capable of implementing an oversampling in its powerful FPGA digital engines, but it turns out that it does not. Rather the Invicta activates the oversampling filters in the Sabre DAC. They are quite configurable and more than adequate to deliver exceptional performance.
I would also highly recommend reading the pages listed under "Invicta" on the Resonessence website which is something I don't typically recommend but in this case there's real information to sink your teeth into and its presented in a very readable fashion. Here you'll learn about why the Analog Devices AD797 op amp was selected for the preamplifier section (spoiler alert - it sounded best) as well as the reasons behind and justification for the Invicta's digital volume control (hint - it did not sound worse). I would also highly recommend watching "Noise Shaping Sigma Delta Based Dacs" presented by Martin Mallison, CTO, ESS Technology at RMAF 2011 (I asked but I suppose I could have just guessed that Martin and Mark Mallinson are brothers). Within this hour-long presentation you'll get a peek into the technology behind the ESS Sabre DACs, their Hyperstream technology, egg laying, martians and leap years (no joke). I found this hour-long video interesting, informative, and exceptionally entertaining.
Behind every great DAC there's a great DAC
Perhaps you can already tell that beyond the faceplate, specifications, ins and outs, and ultra-upsampling I found the Resonessence Labs Invicta DAC to be a thoroughly good-sounding DAC. And this fact struck me within moments of sitting and listening. This was before I dove into the details of what makes it tick which doesn't discount these important details but it does reinforce what matters most when we talk about any piece of hi-fi gear, which is how much we like listening through it.
And the Invicta DAC hardly sounds like anything at all beyond what you feed it. There's a purity to the overall presentation, from bottom to tippy top (I also noted that notes in the upper registers sounded sweet), from macro movement to micro details and everything in between that just screams music. In other words there was nothing about the Invicta's presentation that distracted from the music. Occasionally I would note something like, "Wow, Ron Carter is so fluid" or "Don Cherry's pocket trumpet lives on a very different plane compared to James Clay's sax" or "damn, Bob Dylan sure is clever". I was thinking about the music, the music making, the space, time and mood of the recording, and to my real delight at times I wasn't thinking about anything at all.
Most of my listening was done through the USB input fed from my MacBook Pro running Pure Music but I also loaded the custom Thesycon USB Audio 2.0 drivers (from the included SD Card) for Windows and spent some time doing PC-listening via JRiver. I also brought up my Shindo Cortese amplifier from my library system to run the Invicta as preamp/DAC and from that experience I'd suggest that if you have a digital-only setup the Invicta can certainly function as a fully musical DAC and preamplifier.
The BNC input also got a workout thanks to the review sample Musical Fidelity V-Link 192 USB-S/PDIF converter along with Toslink sent from my MacBook Pro (and also through the V-Link 192 just for fun) and I generally liked each of them but for simplicity's sake going straight USB makes the most sense to me and the MacBook's Toslink output is limited to 24/96 whereas USB isn't.
As you may already know I do not spend much time listening to headphones but I did spend some time listening through my Audio-Technica ATH-W1000s and I'd apply everything I said so far here as well. Nothing but music, nothing but pleasure unless you find being slapped in the face with the benefits of higher resolution audio to be unpleasant. I compared a CD rip at 16/44.1 to a 24/96 HD Tracks download of Ella & Louis and the distance between me and them was foreshortened dramatically by the greater bit depth and higher sample rate version. I also played a recent vinyl rip at 24/192 to a lossy copy of Rickie Lee Jones' Girl At Her Volcano and while I didn't require any convincing this just reinforced the fact that I'd never pay for a lossy download unless there was absolutely no other way to obtain a particular piece of music.
I do wonder how useful people will find that SD Card reader as a means to play back their music. I copied a bunch of tracks onto one, clicked it in and played 'em but for my way of living and listening, I'd imagine I'd spend 99.99% of my time with the Invicta streaming music from my NAS or listening to Internet radio. Sonically I did not detect any night and day differences and the only thing I did notice was my eagerness to get back to my full music library for extended listening.
On that note I had an exchange with Mark Mallinson about this very subject and his response is worth sharing:
Our decision to include the SD card is based upon our belief that over time this technology will gain a lot of momentum. Shortly we will be implementing the SDXC spec for the card reader. This specification allows cards to reach 2 terabytes in capacity. At these kind of levels you will no longer need a computer or music server in the loop for playback as your entire music library can be stored on the SD card.
A Rave In The Right Direction
Sometimes during the review process listening can feel like work. I know this sounds jaded but I'm not complaining just pointing out the human side of things. And this human never once felt that listening to music through the Invicta DAC was anything but pure pleasure.
There's obviously a lot to like about the Invicta DAC. As a matter of fact I'd be hard pressed to note anything worth criticizing beyond offering up the usual caveat that how much you enjoy how something sounds will ultimately fall onto your ears ideally when listening to your system in your room. Of course there's the question of budget and value, issues and answers that exist in your wallet and between your ears. If I can add any value to this process, its in pointing you to things you may otherwise have missed in your search or on your journey by ideally providing a glimpse into those features and aspects of performance that may tickle your fancy. Sometimes I'll even go a step further.
Which is to say if you're looking for a DAC (and preamp and dual headphone amp) to connect you to your music in a wonderfully transparent and engrossing way, I would point you to the Resonnessence Labs Invicta without reserve or hesitation.
Also on hand and in use during the Invicta review: Bladelius USB DAC, Wadia 121Decoding Computer, Wavelength Audio Brick v3, Acoustic Plan DigiMaster DAC