Schiit Audio Yggdrasil DAC and Ragnarok headphone/integrated amplifier
Schiit Audio is the brainchild of two high-end audio veterans: Jason Stoddard, former design chief of Sumo Electronics, and Mike Moffat, founder of Theta Digital.
As you might expect from their company’s unorthodox name (which is pronounced exactly the way you might think), both men share a cheeky and decidedly iconoclastic sense of humour that stands in direct opposition to the sometimes-grandiose pretentions that are so often part of today’s high-end audio world.
Stoddard and Moffat are no-nonsense engineers who believe that offering great value for money is not just a smart idea but also the right thing to do, and that the main objective is to build components that offer pure, blindingly great sound quality and rock-solid technical performance at fair prices. Neither Stoddard nor Moffat has much use for ‘boutique’ components, gratuitously expensive cosmetic treatments, or flashy ad campaigns making dubious claims of ‘magic’ technologies within. At the end of the day, Stoddard and Moffat are down-to-earth designers (and very clever marketers) who, at the end of the day, rely primarily upon good, old-fashioned creative engineering and technical ingenuity—not techno-mysticism or smoke and mirrors, to achieve their goals. As a result, Schiit Audio components tend to evince a certain purposeful, ‘beauty is as beauty does’ vibe that many will find refreshing in a world overly full of hype and unfulfilled promises.
All of which brings us to the subjects of this review: Schiit Audio’s flagship Yggdrasil DAC (£1,980) and matching Ragnarok fully balanced headphone/integrated amplifier (£1,550), which are the finest components of their types that Schiit Audio knows how to build. What’s up with the names? Schiit explains that, “In Norse mythology, Yggdrasil is the world tree: the source of all things.” In short, Yggdrasil (or “Yggy”, as designer Mike Moffat prefers to call it) is intended as the digital source to top all sources. In turn, designer Jason Stoddard adds that, “In Norse mythology, Ragnarok is the end of the world,” which by extension means that the Ragnarok aims to provide ‘the living end’ in terms of top-tier headphone/integrated amplifier performance.
Schiit Audio says the, “Yggdrasil is the world’s only upgradable closed form balanced multi-bit DAC”—a DAC that, on a conceptual level, is different as can be to the traditional ‘24-bit’ or ’32-bit’ delta-sigma DACs commonly encountered in the marketplace. Moffat emphasizes that the Yggdrasil uses a bit-perfect “digital filter with a true closed-form solution,” which means it “retains all the original samples, performing a true interpolation.” The upshot is a digital filter said to provide, “the best of NOS (all original samples retained) and upsampling (easier filtering of out of band noise) designs.” Yggdrasil’s sophisticated bit-perfect, closed-form digital filter is implemented via a powerful Analog Devices SHARC DSP processor. The Yggdrasil is a fully balanced design that uses a total of four Analog Devices AD5791BRUZ DAC devices—two per channel, with the DAC outputs followed by, “fully discrete JFET buffers for balanced output and discrete JFET summing stages for single-ended output, direct coupled throughout.”
To ensure timing accuracy, Yggdrasil incorporates an ingenious Adapticlock system that, “assesses the quality of all inputs, measures their incoming centre frequency and jitter, and automatically routes the input” to one of two clock regeneration systems. Yggdrasil’s VCXO clock regenerator provides the best performance for good sources, while for lower quality sources the DAC also offers a more jitter-tolerant VCO regenerator. Yggdrasil even provides a so-called ‘buy better gear’ warning light that illuminates should a low quality digital source force the VCO clock regenerator to be brought into play. No matter how good or how limited your digital sources might be, Yggdrasil will improve their timing accuracy.
Yggdrasil’s robust power supply provides two transformers (one for the digital power supply, the other for the analogue power supply), plus an input choke for a “discrete, dual mono, shunt-regulated analogue ± 24V supply.” Going even further, ‘Yggy’ offers 12 separate, local, regulated supplies, “for DACS and digital sections, including high-precision, low-noise LM723 regulation in critical areas.”
The DAC provides five user-selectable inputs: AES/EBU via XLR, RCA S/PDIF, BNC S/PDIF, Optical S/PDIF, and USB gen 3, with a series of panel lights to indicate which source is selected. In turn, additional lights show whether the digital audio file being played is a multiple of either 44.1kHz or 48kHz, while also showing the specific multiple that applies (e.g., 1X, 2X, or 4X, etc.). At present, Yggdrasil handles PCM files only, at resolutions up to 24/192.
Why no support DSD for files? The answer is complicated, but involves the fact that Mike Moffat regards DSD as a technically limited format that is not well supported by record labels or by most music streaming/download sites. In short, Moffat’s position is that the overwhelming majority of digital audio content available today is offered in PCM format, typically at resolutions at or below 24/192. In practical terms, then, Moffat reasons that it is better to build a DAC that delivers spectacular performance with the majority of musical material available, rather than a DAC that delivers compromised performance in hopes of supporting the latest ‘flavour of the month’ format.
If Moffat is Schiit Audio’s digital design specialist, then company President Jason Stoddard is the firm’s resident amplifier expert and the man primarily responsible for creating the Ragnarok.
Ragnarok is not only a fully balanced high-end headphone amplifier; instead, it is a versatile ‘amp for all seasons’ that can serve as a headphone amp, a preamplifier, or as a sophisticated, integrated amplifier capable of delivering an impressive 100 Wpc at 4 Ohms into loudspeaker loads.
Obviously the Ragnarok is among the most powerful headphone amplifiers on the planet, but Schiit Audio claims that it is also quiet and refined enough for use with very sensitive CIEMs (custom-fit in-ear monitors). Perhaps needless to say, it is muscular enough to drive any dynamic-type headphone we have ever encountered, and also able to drive many types of loudspeakers—all with abundant headroom to spare. In support of these multiple roles, Ragnarok provides three user-selectable gain settings, ranging from a setting of 1 (for CIEMs and other sensitive earphones or headphones), to 5 (suitable for most headphones including those that are moderately hard to drive), on up to 20 (suitable for loudspeakers or for extremely insensitive and difficult-to-drive headphones).
Technical highlights of the Ragnarok’s circuit include its distinctive, direct-coupled, ‘Crossfet’ Circlotron-style circuit topology, complete with microprocessor controls for operating parameters such as quiescent bias, DC offset, and all fault protection functions. Moreover, Ragnarok incorporates a 64-level, relay-switched, stepped attenuator, plus the aforementioned gain controls. Schiit emphasises that the Ragnarok features, “a whole new gain stage optimized for the Crossfet architecture”—one that offers, “the same feedback level and compensation for all gain levels.”
Those interested in learning more about Circlotron-type amplifier circuits are encouraged to check out Jason Stoddard’s delightful and insightful book, Schiit Happened: The Story of the World’s Most Improbable Start Up. In particular, I recommend reading Chapter 17, entitled, “Resurrecting the Circlotron and Other Mid-Centuryisms”. Schiit Audio first used a Circlotron-type circuit in its successful earlier generation Mjolnir headphone amplifier and then pushed the technology to even higher performance levels in the Ragnarok.
Two of the key advantages of Circlotron circuits, observes Stoddard, are that they are inherently balanced and also comparatively simple to execute, although they do require relatively complex power supplies. Better still, Stoddard says Schiit’s Circlotron circuit, “uses only N-channel devices, so there’s no worry about the N-channel and P-channel devices being mismatched.” One refreshing aspect of Schiit’s design philosophy is that the company is willing to revisit old concepts—in this case the Circlotron circuit, which dates back to the 1950s—while implementing them in completely new, fresh, and thoroughly performance-minded ways.
Like the Yggdrasil, the Ragnarok provides a massively overbuilt power supply that uses a 400VA transformer to feed four separate Circlotron output rails, plus a separate 56VA transformer for the amp’s high voltage rails. There are seven separate regulated supplies for the amp’s front end and control sections, and the entire power supply astonishingly offers a total of “more than 100,000µF filter capacitance” (more than some power amps!).
As the foregoing discussion suggests, Yggdrasil and Ragnarok were both built from the ground up to reach an extremely high level of performance—not built down to achieve a specific selling price. Nevertheless, Schiit Audio’s characteristically value-minded orientation manages to shine through, so that even though the Yggdrasil and Ragnarok are undeniably expensive products, they are by no means ‘crazy expensive’ in light of the sound quality (and quality of build) on offer. In fact, some might even consider them to be bargains, of a sort. But as always, the proof comes in the listening.
During my listening tests, I used the Yggdrasil and Ragnarok to drive my reference Noble Audio 4S CIEMs (to test Schiit Audio’s claim that the Ragnarok was quiet enough for use with CIEMs), and also with four of the finest full-size headphones in my reviewing stable: the Abyss AB-1266, the Audeze LCD-3F, the HiFiMAN HE-1000, and the MrSpeakers ETHER C. At the risk of getting ahead of myself, let me say that the Yggdrasil/Ragnarok pair extracted downright breathtaking performance from all five of these reference transducers.
The Yggdrasil and Ragnarok are highly complementary, so it is hard to say precisely where the sound of one leaves off and the other takes up. Nevertheless, I’ll do my best to distinguish the two.
Once fully warmed up and thermally settled (a process that takes roughly two or three days of continuous operation), the Yggdrasil offers neutral voicing, an extremely low perceived noise floor, plus what appear to be essentially limitless reservoirs of resolution and inner detail. Unlike other highly detailed audio components, however, the Yggdrasil is neither painfully analytical nor sterile sounding. Instead, it offers the very best kind of natural sound, meaning that textural and transient details simply emerge and unfold in the normal course of playback—full, rich, and complete, but never drawing undue attention to themselves. As a result, even familiar musical passages, as heard through the Yggdrasil, seem to take on greater depth and resolution, plus a dramatically heightened sense of expressiveness (as if layers of previously hidden musical information have suddenly been revealed). One other key point is that the Yggdrasil does such an impressive job with 44.1kHz/16-bit files that, to be honest, it hardly seems necessary to step up to higher resolution formats (you can hear the difference between standard and high-res files, but Yggdrasil dramatically narrows the sonic gap between the two).
The Ragnarok offers similar sonic virtues to the Yggdrasil, but with two important added benefits. First, at its lowest gain setting, the Ragnarok proved to be extremely quiet, authoritative, and yet and full of subtlety and nuance. This combination of virtues enable the Ragnarok to deliver what was hands down the best sound that I have ever heard from my reference Noble 4S CIEMs. In fact, the Ragnarok helped my Noble CIEMs achieve levels of transparency and dynamic expression I hadn’t previously thought possible.
To appreciate what I mean, consider the track “Ghazali” from master bassist Renaud Garcia-Fons’ album Oriental Bass [Enja, 44.1/16] as played through Yggy and Ragnarok through the Noble 4S CIEMs. “Ghazali” presents a thoughtful, even meditative, bass solo that, through the Schiit Audio-driven Noble CIEMs, conveyed a downright uncanny sense of transparency, presence, and warmth, replete with the innate ‘woodiness’ of the acoustic bass and an overarching sense of gravitas, as notes from the large instrument swelled outward to fill the room. What caught me, in particular, was the Yggy/Ragnarok pair’s ability to lift the performance of the CIEMs to a point where they conveyed a sense of actually being present in the original recording space.
Second, at higher gain settings the Ragnarok offers what can only be called ‘bottomless pit’ levels of power coupled, once again, with extraordinary sonic subtlety and nuance. As a result, Ragnarok effortlessly revealed the distinct sonic personas of each headphone, making it much easier to grasp and to compare their relative strengths and sonic merits. Ragnarok imposed little if any sound of its own on my reference CIEMs and headphones, but rather revealed (and exploited) the signature strengths of each model in a more complete way than ever before. If you seek an amp that can help your transducers ‘be all that they can be’, please know that the Ragnarok finds itself in the company of such excellent (but also significantly more expensive) designs as the Cavalli Audio Liquid Gold and the Wells Audio Headtrip.
By way of illustration, let me describe the Yggy and Ragnarok’s handling of composer/violinist Mark O’Connor’s Fanfare for the Volunteer [Sony Classical, 44.1/16] as played through the Abyss AB-1266 planar magnetic headphone. Fanfare for the Volunteer offer a real workout for audio components in that it begins with passionate low percussion passages, then introduces a stirring brass fanfare, and finally moves forward into a light, lithe, dance-like string passage and violin solo. The track demands everything from low bass power and control, to fierce midrange dynamics with refined textural shadings, and finally terrific delicacy and transient speed.
The Abyss headphone is capable of delivering all of these things, but only—in my experience—when pushed by true top-tier components (merely good gear simply isn’t good enough to elicit optimal performance from the AB-1266 headphones). But the Schiit components more than rose to the occasion; in fact, they helped my AB-1266s sound better than I have ever heard them sound in my home. Their power and control on the low percussion section was almost frightening, while their burnished, golden treatment of the brass fanfare was similarly intense, yet beautifully balanced and realistically weighted. But the piece de resistance was their handling of the violin solo, which I noted caught the “light, sunlight-sparkling-on-open-water, dance-like quality of the violin.” The Abyss is capable of great performance, but only when the DAC and amp are up to the task, as the Yggdrasil and Ragnarok plainly are.
Are there any drawbacks to these components? I can think of only two minor ones. First, given that Yggdrasil is upgradeable, I would like to see Schiit expand its capabilities to include 352.8kHs and 384kHz PCM files. Second, I would urge Schiit to look into the idea of creating a remote control for the Ragnarok, which would make it more useful for those who sometimes sit beyond reach of their audio components.
Rarely have I been as favourably impressed by a DAC and headphone amplifier as I have been by the Yggdrasil and Ragnarok. Though neither component comes anywhere near being the most expensive offering in its respective class, both offer performance at or near the best levels possible, regardless of price. For that reason alone, Yggdrasil and Ragnarok both deserve the heartiest of recommendations.
Schiit Audio Yggdrasil
Type: Solid-state multibit DAC
Digital Inputs: One AES/EBU XLR, RCA S/PDIF, BNC S/PDIF, Optical S/PDIF, USB Gen 3
Analogue Outputs: 1x pr stereo single-ended RCA jacks, 1x pr stereo balanced XLR connectors
DAC Resolution & Formats: PCM to 24bit/192kHz
Frequency Response, Analogue: 5Hz – 100kHz, -1dB
THD: < 0.006%, 20Hz – 20kHz, at full output
IMD: < 0.007%, CCIR
Output Voltage: 4.0 V RMS (balanced), 2.0 V RMS (single-ended)
Dimensions (H×W×D): 9.85 × 40.6 × 30.5cm
Weight: 11.35 Kg
Schiit Audio Ragnarok
Type: headphone amplifier/preamp/integrated amp
Inputs: 3x pr single-ended stereo analogue RCA jacks; 2x pr balanced stereo analogue XLR inputs
Outputs: 1x single-ended 6.35mm TRS headphone jack, 1x balanced 4-pin XLR headphone jack, 1x pr single-ended stereo preamp RCA jacks, 1x pr balanced stereo preamp XLR jacks
Frequency response: 2Hz – 180kHz, -3dB
Gain Modes: 1 (0db), 5 (14dB), and 20 (26dB)
THD: <0.006%, 20Hz – 20kHz, at 1V RMS, all gain modes.
IMD: <0.008%, CCIR at 1V RMS, all gain modes.
Signal/Noise ratio: >103dB, unweighted, referenced to 1V RMS, in gain = 1 mode
Power Output: 4 Ohms: 100Wpc RMS, 8 Ohms: 60Wpc RMS, 32 Ohms: 15Wpc RMS, 50 Ohms: 10Wpc RMS, 300 Ohms: 1.7Wpc RMS, 600 Ohms: 850mWpc RMS
Dimensions (H×W×D): 9.53 × 40.6 × 30.5cm
Weight: 14.52 Kg
Manufacturer: Schiit Audio
Tel: +1 (323) 230-0079
UK Distributor: Schiit Europe
Tel: +44 (0) 1494 956558