Late last night I was about to conduct a final listening session with the Schiit Audio Yggdrasil DAC. I planned to finish writing this review after listening to one, maybe two albums. After all, I really didn't need to listen to the DAC for another minute, let alone another couple of hours. I already spent quite a bit of time with the Yggdrasil, but I just had to give it one more listen. I turned out the lights and turned up the volume on a Constellation Audio preamplifier. A track or two into the first album and I knew my plan for the evening was moot. I was not going to be able to stop listening and start writing. The sound was so good and the experience so enveloping, that I couldn't stop listening until the cause of my head bobbing switched from incredible music to incredible sleepiness. Hours after the listening session began, I had to call it a night and get some rest. I was eager to write, but I was in no condition to concentrate and collect coherent thoughts. This is the kind of component the Yggdrasil is, one that can suck the listener in and alter one's plans for the evening. I've enjoyed the Yggdrasil so much since I took delivery of the unit that I can say it's unequivocally one of the best DACs at reproducing acoustic music I've ever heard. Of course this DAC is fabulous at amplified / electric music as well, but there is something about its ability to convey realism when reproducing acoustic instruments that is remarkably alluring. In my experience, sound quality of this caliber comes at a price that most of us simply can't afford. We read the reviews of ultra high-end products as aspirational buyers who may one day get lucky enough to find a gem on the used market for well below the original price. Many audio enthusiasts know what I'm about to say, but those who are unfamiliar with the Yggdrasil, and Schiit Audio in general, should stop skimming this review and pay close attention. The aforementioned sound quality of the Yggdrasil, Schiit Audio's top-of-the-line digital to analog converter, can be had for $2,299 USD. That's a new-in-box component with a fifteen day return policy and a five year warranty, for less than the cost of sales tax on many items in this wonderful yet sometimes crazy world of high end audio. Come along as I share my extraordinary experience with the Schiit Audio Yggdrasil digital to analog converter.
Schiit Audio and DAC Topology
Two audio industry veterans walk into a bar… No, two audio industry veterans get together to start a new company in June 2010. Just what every business analyst recommended, start an audio company focusing on sound quality and do it during the worst economic crisis since the great depression. What could go wrong? That's obviously a rhetorical question, but the facts are the facts. Schiit Audio was founded by Jason Stoddard and Mike Moffat in 2010. These guys created some terrific and groundbreaking products in their previous lives, and wanted to shake things up a bit in the HiFi industry. There's really no such thing as an overnight success, but it sure seemed like Schiit Audio hit the ground running with accolades from everywhere and a huge fanbase immediately, especially with the Head-Fi crowd. Propelling this success was the founders' willingness to speak their minds and do so in a lighthearted manner, yet still get the point across that their products were as serious as a heart attack. Good rapport between a manufacturer and potential customers only goes so far, the physical products are where the rubber meets the road. Release high quality and high value products, and enthusiastic customers will be the best marketing team for which a company could ever hope. That's exactly what Schiit Audio did, and people sang its praises in audio forums the world over.
I was late to the Schiit Audio party compared to most audio enthusiasts. I heard about the company and saw its products, but for some reason I simply moved on to other things. That is, until the Yggdrasil DAC was announced, then the ball started rolling. I researched the Yggdrasil DAC and immediately emailed Jason at Schiit to obtain a review sample. Like most good companies, Jason told me to wait until the customers who'd pre-ordered the DAC received their units. I had no problem with that, other than my short patience. In August 2015 the opportunity arose for me to attend the inaugural Schiit Show in southern California. This was my first real opportunity to spend time listening to Schiit's products and equally as important to spend time talking with Schiit's digital wizard Mike Moffat. I spent a large amount of time, the evening before the show started, talking to Mike. The conversation started with a technical discussion of many concepts from USB audio to DAC topology. By the end of the night we were talking about everything with the exception of audio. Prior to the end of the Schiit Show I gently reminded the Schiit team that I was still waiting for a Yggdrasil review unit. To my surprise the company had delivered DACs to all its customers who pre-ordered and there was a unit available for review. The Yggdrasil arrived a week later and was immediately placed into my audio system.
Before getting into the details of how the Yggdrasil converts digital into analog audio, I want to make sure readers understand that this review is neither a referendum on DAC topology, nor a treatise on multibit versus Sigma-Delta designs. Thus, I am purposely leaving out some of the minute details that only serve to move the review comment section further into the weeds. Trying to find the best sounding component by debating multibit versus Sigma-Delta topologies based on specifications only is preposterous. Let me be a bit more blunt, it's stupid. The final product of a DAC, the analog audio output quality, depends much more on the intellect of its designer than the physical hardware and the test measurements. When both great internal components and a great engineer are combined, the outcome can be fabulous no matter which road one takes to Rome (or sonic heaven).
The "Yggdrasil is the world’s only closed-form multibit DAC, delivering 21 bits of resolution with no guessing anywhere in the digital or analog path." According to Schiit Audio. Let's dive into that statement a bit. Many audio enthusiasts will immediately see the 21 bit number assume this DAC is inferior to other DACs that claim 24 or even 32 bits of resolution. Several manufacturers today advertise the fact that their DACs feature multiple 32 bit DAC chips per channel. Making a judgement on a DAC's superiority or inferiority based on the number of bits advertised is foolish. For example, a 24 bit DAC has a theoretical maximum SNR of 144 dB, but the best current DACs can only obtain an SNR of 124 dB or 21 bits due to the noise floor of the components. In addition, human hearing has a dynamic range of about 120-130 dB. What's more, DACs have what's called Equivalent Number of Bits (ENOB) to signify the actual resolution of the DAC. A closer look at many 32 bit DACs reveals they actually have an ENOB of 19.5. Can you see why making judgements about DACs based on specifications is ridiculous?
Readers may be asking themselves, what happens when I play a 24 bit recording on the Yggdrasil if it only supports 21 bits? The reality is that 24 bit recordings don't have 24 bits of resolution / information. It's possible to select 24 or even 32 bits as the output resolution for the Yggdrasil in Audio Midi. The truth is that it doesn't matter on any DAC. Note 1: Vinyl playback has about 12 bits of resolution, CD has 16 bits. Note 2: The Yggdrasil doesn't support DSD.
Two more items I want to touch on are the filtering and hardware components inside the Yggdrasil. Again, these items individually don't mean a thing (if the designer ain't got that swing). Schiit Audio uses its own closed-form filter that's hallmark is using the original samples, not throwing the original samples away while upsampling like most DACs. Good, bad, or indifferent, this is Schiit's way of filtering. Schiit says it doesn't do guess work because it keeps the original samples. On the CA forum, Mike Moffat elaborated further by saying,
"It is a digital filter/sample rate converter designed to convert all audio to 352.8 or 384KHz sample rates so that it may drive our DACs. You get it uniquely from us; it is our filter. It took five people many years to design and perfect at the dawn of digital playback, way back in the early eighties. It keeps all original samples; those samples contain frequency and phase information which can be optimized not only in the time domain but in the frequency domain. We do precisely this; the mechanic is we add 7 new optimized samples between the original ones. All digital filters multiply the original audio signal by a series of coefficients which are calculated by a digital filter generator. Over the years, before Theta Digital was born (my original company), we developed this filter design/generator. The common digital filter method is a Parks-McClellan algorithm, which has been used in all of the older oversampling chipsets, and persists to this day as the input filter in most Delta-Sigma DACs. Why? I assume it is because it is royalty-free, and the algorithm is widely available as are digital filter software design packages to aid in a cookbook approach to the design. Now Parks McClellan an open form math solution, which means that the coefficient calculation is a series of approximations which always get halfway there. This of course, means it never completely solves. The worse news is that all original sample are lost, replaced by 8 new approximated ones. Further, the Parks McClellan optimization is based on the frequency domain only – flat frequency response, with the time (read spatial) domain ignored. Our filter is based upon closed form math – the coefficients are not approximations, the equations solve; the matrices invert and the math is done. The filter also optimizes the time domain."
In addition to Schiit's unique filter, the company uses unique hardware (at least in the audio world) in the Yggdrasil. Schiit uses four of the Analog Devices AD5791BRUZ DACs that are typically used in MRI imaging and military weapons. These DACs aren't trivial to implement in a digital to analog converter. I've heard many engineers in the industry suggest that the newest Sigma-Delta chips can be implemented much easier than a multibit design and that it doesn't take much to get a Sigma-Delta DAC up and running. It certainly takes quite a bit to get a Sigma-Delta to sound as good as possible, but nonetheless Schiit's selection of the AD5791 DAC has made its job significantly more difficult. In other words, not every engineer is capable of implementing the AD5791 in a great sounding audio component.
The Yggdrasil DAC is built on a very solid technical foundation that translates terrifically into pure sonic enjoyment. This is what it all comes down to, enjoying the sound that comes out of one's audio system. My system for this review consisted of the Aurender N10 music server -> Yggdrasil DAC -> Constellation Audio PreAmp 1.0 -> Constellation Audio Mono 1.0 amplifiers -> TAD CR1 loudspeakers, all cabled with Wire World Series 7 Platinum. As I said in the opening paragraph, the Yggdrasil is unequivocally one of the best DACs at reproducing acoustic music I've ever heard. The overall sound signature of this DAC is a bit thicker in the midrange than I am used to hearing in some of the other DACs I've had through my listening room. One other quality that is very noticeable through the Yggdrasil is the amount air around the instruments. This DAC doesn't have the most air I've ever heard, in fact it seems to reproduce less air around instruments than most DACs. However, the more I listened the more I thought it's entirely plausible that the Yggdrasil could be on the right side of history, if you know what I mean. The multibit topology in the Yggdrasil eliminates the Sigma-Delta problem is pre and post ringing. I may be incorrect here, but I believe the post ringing in Sigma-Delta DACs may be responsible for memorializing transient events and creating more air around instruments than is actually present in the recording. Thus, the Yggdrasil may be reproducing just the transient event, nothing before or after, more accurately. Another impression I received when comparing the Yggdrasil to the sound of other DACs, is that the other DACs reminded me of an old boombox I had in the 1980s that had a setting called ST-WIDE. The Toshiba boombox had a setting for Mono, Stereo, and ST-WIDE (Link). When using the ST-WIDE setting the sound grew much larger in an inauthentic manner that was pleasing for a little while and would have been really neat had I never heard what the normal Stereo setting sounded like. I'm not suggesting the other DACs in my comparison sounded anything like the old Toshiba boombox, rather these DACs may have an unnaturally large soundstage or be memorializing transients to sound bigger than the recording.
Let's go a bit deeper into the Yggdrasil reproducing unamplified acoustic instruments, specifically Gary Karr's double bass. His instrument is commonly known as the 1611 Amati double bass, given to him by the widow of Serge Koussevitzky. However, further research into this bass reveals that it has a history all its own. In 2005 the Tree Ring Society released a paper detailing its investigation into the instrument. The Society found that the bass was not made by the Amati brothers, Antonio and Girolamo, in Italy in 1611. According to the Tree Ring Society, "We used four reference tree-ring chronologies developed from treeline species in the European Alpine region to anchor the dates for the tree rings from the double bass absolutely in time. The bass yielded a 317-year long sequence, the longest sequence yet developed from a single musical instrument. Statistical and graphical comparisons revealed that the bass has tree rings that date from 1445 to 1761. Based on the strength of these correlations, the spruce tree harvested to eventually construct the double bass likely came from the treeline Alpine area of western Austria, not too far from Obergurgl at the Italian border. Our results demonstrate that the double bass was not made by the Amati Brothers, but likely by French luthiers in the late 18th Century." What does this dendromusicology have to do with the Yggdrasil? It's where my mind went when listening to Gary Karr's album Bass Virtuoso. The sound was so natural and so good I wanted to know more about the actual double bass used in the recording. The first track on the album, Henry Eccles: Sonata, has such a realistic and organic sound one can get the illusion of smelling the rosin on the black hair of Gary Karr's bow. Rumor has it that black haired bows produce a rougher sound as opposed to smooth sounding white haired bows. The coarseness and the beautiful vibrations off the Spruce wood of the bass were almost palpable. Track seventeen o the same album, Alec Wilder: Sonata for String Bass & Piano Part I, starts with Gary plucking the double bass strings (pizzicato) followed by returning to the bow and accompanied by a piano in the right channel. The whole track had a beautiful, lush, and sweet sound through the Yggdrasil that can't be denied. I felt like I had a front row seat to this concert right in my listening room. The only thing that could have made this experience more realistic is if the Yggdrasil had a scratch-n-sniff option. Emanating the scent of freshly cut Spruce would have sent me over the edge.
Readers actually interested in the Tree Ring Society's research can find it here -> PDF Link
I briefly want to touch on a Classical piece of music that totally sucked me into listening to the entire one hour performance. Usually when I write about Classical, my lack of knowledge shines brighter than anything else I write, and I expect this to be no different. I put on Passacaglia, the sixth track on the Reference Recording album of Michael Stern and the Kansas City Symphony playing Britten's Orchestra. I usually don't get that enthusiastic about this track until it gets loud (crescendo) near the finish. However, the time I was thrown for a loop twenty seconds into the track. The sound of the cello as the cellist gently pushes and pulls the bow across the strings is incredible. Not only could I hear spacial queues and the surrounding environment, but I could figuratively see and feel the wood of the instrument and the texture of the strings. The sound just resonated from the body of the cello and into the entire concert space. My usual favorite parts of Passacaglia, the eerie sounds of the string section at 4:25 and the huge booms of the drums at 5:10 followed by a massive collection of deep horns (tuba?) at 5:46, all sounded spectacular. After listening to Passacaglia, I started the album from track one and listened to the entire thing start to finish. That's very unusual for me when listening to a Classical piece of music.
The 2011 remaster of Jack Johnson's Brushfire Fairytales contains great music that sounds great, and also provides great material for evaluating audio components. Specifically, the second track titled Middle Man. At 0:11 into the track the percussionist Adam Topol hits a snare that sounds different through every DAC I've heard in my system. Some DACs produce an incredible amount of air around this snare while others make the snare sound completely dead. The Yggdrasil is the first DAC that has made me reconsider what this snare "should" sound like and question the large amount of air I previously thought was correct. Without being present at the recording, I admit that I have no reference for what is the correct sound of this snare. I can only use my judgement and my taste. Listening through my current reference DAC the Berkeley Audio Design Alpha DAC RS, there is a tremendous amount of air and space surrounding the snare in Middle Man. The drum head is hit and the sound seems to rise into the air and hang, reverberating around the recording space, before decaying. This is a wonderful sound that can really place the listener in the recording studio. Listening to this through the Schiit Audio Yggdrasil gave me a different perspective. The sound of the snare doesn't rise as high or hang in the air as long or give one the sense of a recording space quite as large. Perhaps the Yggdrasil isn't memorializing the transient event because it doesn't "feature" pre/post ringing. I'm not sure the cause, but I am sure of my listening impression. There is a difference in reproduced sound that may not even be correct in either DAC, but both are definitely capable of sound quality superior to that of much of the competition at all prices.
One of my go-to albums for listening enjoyment and feeling a bit on the dark side, is Leonard Cohen's Old Ideas. The second track Amen is full of juxtaposition that's a delight for the ears. Of course Leonard's vocal performance is that of a dusty, coarse, baritone with a microphone seemingly placed behind his front teeth. The vocal is supported by a deep electric bass throughout the track. Through the Yggdrasil each bass note is clearly delineated as if the listener can visualize Roscoe Beck plucking the strings for each note. Many listeners may like this track for the bass and gravely vocal performance, but what really makes it special for me is the backing vocal and the violin performance from Bela Santelli and Robert "OBM" Koda. The saying that opposites attract is right on within this track. About one minute into the track the violin starts weeping in the background followed by a subtle backing vocal abut ten seconds later. Throughout the rest of the track the violin can be heard coming in and out as well as the soothing background vocalists taking a more prominent role. The Yggdrasil's ability to reproduce each instrument as a distinctly different entity, to separate each bass note, to let the violin weep and hang in the air, and to recreate a smooth backing vocal in the face of a coarse lead vocal, is absolutely wonderful.
I could go on all day writing about the wonderfully organic and natural sound of Peter, Paul and Mary's In The Wind album, how great the harmonizing vocals of the trio sounded, the palpability of the acoustic guitar on the title track to Van Morrison's Astral Weeks, and how seductive Van's vocal on Into the Mystic through the Yggdrasil, but it's time to shake things up a bit. On August 25, 1993 Calvin Broadus was in a Jeep with his bodyguard McKinley Lee, when the men were threatened with a gun by Philip Woldemariam. McKinley Lee pulled out his own gun and shot Woldemariam, killing him. Lee and Broadus spent the next week on the lam, turning themselves in only after the MTV Music Video Awards. The two men were later acquitted of several crimes including murder. After the shooting Calvin Broadus created a song called Murder Was The Case and released it on his debut solo album called Doggystyle. The album was the first debut CD to enter the Billboard Pop charts at number 1. Astute Computer Audiophile readers may recognize the name Calvin Broadus as the rapper who goes by the name Snoop Dogg, or Snoop Lion, or Snoopadelic. Listening to Murder Was The Case through an audio system worth nearly $100,000, and specifically through the Schiit Audio Yggdrasil was a blast (no pun intended). The version of this track available on the soundtrack of the same name is actually better than the version on Doggystyle, thus that's the one to which I listen. The opening sound of the blades of a helicopter rotating followed by a booming drum echo should be experienced at higher volumes than normal listening. The high pitched synthesizer heard throughout much of the track is an essential yet annoying piece of the track. Nonetheless, Snoop gets my head bobbing with the infectious beat and his lyrical genius repeating "Murder, murder was the case that they gave me" with a bevy of backing vocalists. As Snoop raps, "My little homey Baby Boo took a pencil in his neck, And he probably won't make it to see twenty-two, I put that on my Momma; I'ma ride for you Baby Boo" the listener can't help but empathize with life in the LBC back in the mid-nineties. The Yggdrasil really bring out the emotion in the line, "No more indo, gin and juice, I'm on my way to Chino, rolling on the grey goose." Overall the sophisticated sound of the Yggdrasil's multibit architecture and its proprietary closed-forum filter really help Snoop's ode to a real life killing come through in a way many DACs simply can't manage. Note 1: The previous few sentences are to be read with an eye toward the humorous, keeping in mind that taking oneself too seriously can be detrimental to one's health. Note 2: Snoop's Doggystyle album was released three days after my eighteenth birthday in 1993. To say this album kept a few parties jumping in the ensuing years of my life would be an understatement.
When a pair of industry veterans get together to create excellent products for incredibly reasonable prices, consumers win. Schiit Audio's products range in price from $79 for the Fulla USB DAC / headphone amp to its flagship $2,299 Yggdrasil DAC. Based on my experience with countless DACs and after spending a couple months with the Yggdrasil, I can say without a doubt that this DAC is very special. It's one of my favorite DACs available today. In fact, I will happily mention the Yggdrasil in the same sentence as some of my other favorites, the Berkeley Audio Design Alpha DAC RS ($16,000) and the EMM Labs DAC2X ($15,500), when talking to fellow audio enthusiasts. The Yggdrasil is one of those products that subtly grabs hold of the listener, yet the listener is the one who can't let go. I couldn't stop listening through the Yggdrasil enough to write this review on time. The Yggdrasil is a musically addictive drug without the expense and potential repercussions. When something is this enjoyable and the consequences of continuing its use aren't dire, the result is a foregone conclusion. More listening. The Yggdrasil has a rare ability to reproduce acoustic music on a level with some of the best DACs I've heard. Resonating Spruce wood from a double bass sounding so realistic as to breathe new life into old music, is a characteristic of the Yggdrasil. The juxtaposition of a coarse bowed bass with a silky smooth violin playing out in front of the listener as the sound simply hangs in mid-air until it appropriately decays, is part of an experience readily available through this DAC. The Yggdrasil has a really solid yet simplistic build quality on the outside and very selective component use on the inside. However, I believe the Yggdrasil's performance has much more to do with intellectual property than any other factor. Any manufacturer can use identical hardware in a competing product, but only Schiit Audio has its closed-form filter. In addition, the amount of engineering expertise required to implement the Analog Devices AD5791BRUZ DACs in an audio product is more than many companies have or costs more time and money than they can afford. To say the Yggdrasil is a unique product that's equal to much more than the sum of its parts is an understatement. Great technology and engineering coming together to reproduce fantastic sound quality at prices unheard-of in this industry is characteristically Schiit Audio. The Yggdrasil is a disruptive product that I can't recommend enough to both new and experienced music aficionados. Add to cart and enjoy.
- Product - Schist Audio Yggdrasil DAC
- Price - $2,299
- Product Page - Link
- User Manual - PDF Link
- USB Drivers - Link
Where To Buy: Schiit Audio
- Source: Aurender N10 Caching Music Server, MacBook Pro
- DAC: Berkeley Audio Design Alpha DAC RS
- D-to-D Converter: Berkeley Audio Design Alpha USB
- Amplifiers: Constellation Audio Mono 1.0 / Monoblock Power Amplifiers, Pass Labs XA160.5 Monoblocks
- Preamplifier: Constellation Audio PreAmp 1.0
- Loudspeakers: TAD Labs CR1 Compact Reference
- Remote Control Software: Aurender Conductor, Roon Remote
- Remote Control Hardware: iPad Air 2
- Playback Software: Roon
- Network Attached Storage (NAS): Synology DS1812+, CAPS v4 Cortes Server
- Audio Cables: Wire World Platinum Eclipse 7 Interconnects (XLR & RCA), Wire World Platinum Eclipse 7 Speaker Cables, Wire World Platinum Starlight 7 Digital Cables,
- USB Cables: Wire World Platinum Starlight 7 USB 2.0, AudioQuest Diamond USB 2.0, Nordost Purple Flare USB 2.0
- Power Cables: ALO Audio AC6 Power Cables
- Ethernet Cables: AudioQuest Vodka Ethernet Cables throughout system
- Network: Cisco SG200-26 Switch, Baaske MI-1005 Ethernet Isolator, Apple AirPort Extreme, PFSense Router / Firewall, Motorola - Arris SURFboard SB6183 Docsis 3.0 cable modem, Comcast Extreme 150 Mbps Internet Service