Schiit Gungnir Multibit DAC & Mjolnir 2 Hybrid-Tube Headphone Amp Review

Schiit has been in the audio game for quite some time now and has accrued a legion of followers from their simple and humble beginnings. Despite their crude name, the company’s products are anything but that and feature outstanding design topology with a high quality premium feel. Made exclusively in the US, Schiit’s mantra has been for their products to be handed down from generation to generation and their generous 5 year warranty substantiates their aim.

Jason Stoddard and Mike Moffat (co-founders of Schiit Audio) had been planning to unveil a new device since last summer, and finally they are here. The Gungnir multibit, an R2R architecture DAC and the Mjolnir 2, a hybrid-tube headphone amp are the newest products from Schiit Audio. These two models have been cast back into the spotlight having been revitalised from their previous iterations with brand new trickle-down technology.

At a price of $2,098, the pair is relatively expensive and requires a well-thought out investment. Having reviewed their more budget Magni 2U and Modi 2U, however, it is clear to see that Schiit produces quality products. Without hesitation then, I would strongly recommend these to the serious audiophile looking for great sound and willing to make the investment.

Box and Design

The Schiit products come well packaged in a large cardboard box. As with all Schiit products, the white cardboard features minimal packaging which exudes class and sophistication. The stack comes with each of their respective power cords (UK, US, Australian or Euro) and the tubes for the Mjolnir Amp. Note that RCA/phono cables need to be purchased separately.

On the topic of design, the brushed aluminium chassis of both the DAC and amp are truly stunning. Like their more budget version products, the design is a real testament to Schiit’s craftsmanship and premium appeal. The 24 lb pair stacks nicely with even symmetry and would sit proud on any surface it occupies.

Schiit Mjolnir 2 Build & Features

The Mjolnir 2 amp represents the first of its kind by implementing a design which allows users to go solid-state or tube, balanced or single-output. The clever innovation is the LISST (Linear Integral Solid-State Tube) which is a piece of circuitry within a tube-like body designed to fit within each of the 9 pins of the amp. The LISST offers a solid state signature but the overall sound can be preferentially changed through the rolling in of the 6BZ7 tubes provided or aftermarket ones such as the 6922. Whatever the case, the user is in control of the sound they want and can tailor the Mjolnir experience by tweaking to their requirements 

Front
On the front of the Mjolnir 2 is the potentiometer, a power LED, low/high gain switch, input select, balanced headphone output and single-ended headphone output (left to right). The potentiometer is smooth with tactile resistance to prevent accidental turning. The gain switch is nicely implemented on the front to allow easy access. The 6.35mm single output jack requires a converter for 3.5mm jack headphones and the balanced, a 4 pin male XLR termination. Overall, it is evident that the amp here hosts a wealth of different options for the user and improves on its predecessor, the Mjolnir, by offering single-ended outputs as well as the option to toggle between different RCA inputs.

Rear
On the rear of the Mjolnir 2, there is a balanced input which allows users to connect to a balanced source with 3 pin cables. Next to this, the single-ended output resides where connections to the Gungnir Multibit or any other DAC can be made with RCA cables. The single and balanced preamp outputs offer even more options by letting users to connect to external powered speakers. Finally, the power switch and inlet are located on the far right of the device.

Top (Tube Rolling)
The Mjolnir 2 has two 9 pin sockets embedded within the amp which allows users to roll different tubes to create a wide-varying flavor of sounds. The compatible list of tubes include the: 6BZ7/ 6DJ8 / 6922 / ECC88 / E88CC with the LISST tubes being another addition to this.

The tube-rolling experience of the Mjolnir 2 was quite a cumbersome process having to rock both tubes in a circular motion before they came loose. A way to overcome this, however, was the implementation of socket-savers (a surrogate 9 pin device) which implant into the 9 pin sockets of the Mjolnir 2. The nifty equipment also has sockets of its own which can be used to raise the platform of the tubes allowing them to be more easily removed while saving the original sockets from general wear and tear. A highly recommended pair of these can be found over at the Tubemonger website.

Internals & Power Supply
Incorporating a unique circlotron topology, the Mjolnir 2 possesses a 4V balanced output which delivers 8W RMS per channel into 32 Ohms and 425 mW RMS per channel into 600 Ohms. Hence, it is able to drive the most sensitive of IEMs to full-scale headphones requiring large amounts of power.

Schiit Gungnir Multibit Build & Features

Front
On the front panel, the input select button permits users to cycle through various means of inputs including USB, Optical, RCA Coaxial and BNC. These various methods of input each have their own LED light (note that only one input can be selected at any one time). Finally, the LED on the far light indicates a VXCO regeneration issue which usually resolves on its own. If it does not, then Schiit recommends to buy a new source because the source causing the problem is off-frequency.

Rear
As with the Mjolnir, there are various forms of outputs and inputs on the rear of the device. These include RCA single and XLR balanced outputs, 4 means of input (USB, Optical, RCA Coaxial & BNC) and finally the power switch.

Internals & Power Supply
As mentioned above, Schiit have employed trickle-down technology from their flagship Yggdrasil DAC to make the Gungnir Multibit (Yggy junior) more affordable to the audiophile market. This consists of the same propriety filters that Yggdrasil uses as well as the obvious precision multibit DACs. However, where it differs from its older brother is that the Gungnir Multibit’s DACs are AD5781BRUZ compared to the more expensive Yggy’s AD5791BRUZ. As with the former delta-sigma Gungnir DAC, the multibit version also utilizes the adapticlock VCXO/VCO clock regeneration as well as the same four modalities of input. To conclude, the fully discrete JFET-input stage for current gain and filtering is said to result in what Schiit claim to be “exceptional performance for the price”.

Sound Quality

Schiit Gungnir Multibit

Now for the most important part, the sound. Starting off with the Gungnir Multibit (Gumby), the tonality is quite remarkable. Sounds seem to arise from a broad expanse with spatial cues being projected both wide and deep. Imaging is top-notch but the slightly warm tone that this DAC imparts along with its lack of forthright transients places it slightly behind the much more expensive Schiit Yggdrasil and PS Audio Perfectwave II models in overall separation and resolution. This is a real testament to the Gungnir Multibit as it essentially able to compete with heavyweights many times its own price bracket. The Gumby is able to sound warm, full and smooth while at the same time being highly resolving. A truly great hallmark of any set-up, this talent makes the Gumby a go-to option even in the face of technical beasts because of its organic and liquid-esque quality. It would not be a far off statement then, to liken these to a vinyl system due to its inherent signature and lack of glare. 

The Gumby renders vocals as natural and spacious whilst seamlessly forging layers to sound without making tracks sound artificially bloated or unrealistic. The linear presentation extends to high frequencies while offering excellent bass depth and extension. A small nit-pick here would be that the high frequencies could have been extended just a bit more to compete with the likes of the Yggdrasil, however for the price, it is still magnificent. Compared to the Resonessence Invicta, the Gumby masterfully avoids stridency in the upper mid and treble regions whereas the former system is all too familiar with the ESS Sabre glare.  

An important point to remark is that while the Schiit Gungnir Multibit offers great sound, the process of getting there does require some burn-in. Initially, for example, the DAC seemed slightly congested and thick but within a short period of time, frequencies open up creating a stellar and immersive soundscape. Schiit recommends that users leave the units on 24/7 however the sound is still proficient following a cold start.  

Schiit Mjolnir 2

Unafraid of pushing the boundaries of innovation, Schiit have not failed to live up to task with the Mjolnir 2. A swiss army knife of amps, the Mjolnir goes big with its balanced hybrid topology. With the linear-integrated solid-state tubes (LISST), the Mjolnir 2 sounds very neutral with good bite, pace and cohesion.  

However, the stock 6BZ7 tubes take this up a notch with increased musicality, air and dynamism compared to the LISST’s relatively flat signature. Tonal balance is simply outstanding and this even improves with the different varieties of 6922 tubes available. Compared to ALO’s continental dual mono DAC/Amp, the Mjolnir 2 sounds more holographic with slightly better separation of elements. The Continental, however, is ever so slightly faster in transient response with its stock tubes compared to those of the Mjolnir’s. Micro and macro-dynamics are well preserved with the Mjolnir sounding both dynamic and cohesive. 

With regards to matchability, noise floor is exceptionally low as the Mjolnir 2 is able to drive the entire headphone industry from very efficient IEMs such as the Rock-It Sounds R-50, DUNU DN-2000 & Titan 5s to more mid-power devices such as the HiFiMAN HE-560 and finally high-impedance sets like the Beyerdynamic DT 880s.

Tube rolling
As with the ALO CDM, the Gumby is made to tube roll with a list of compatible tubes noted above.

Telefunken E188CC
This pair of vintage new old stock (NOS) tubes make a fine addition to the Mjolnir 2 and are consistently better than the stock ones provided by Schiit. Bass extension is greater and more impactful on the E188CC’s compared to the polite tuning of the 6BZ7s. The E188CC edges the 6BZ7 in euphonics as well by divulging a warmer and more open tuning next to the more neutral signature of the 6BZ7s. Elements are better separated and the E188CCs represent an overall mighty fine tube. An excellent eBay service which sells the same type and other NOS tubes can be found here; prices start from $300+/pair.

Phillips Miniwatt SQ E88CC
This pair is another excellent choice with its very lush midrange. The sound is more focused here than the Telefunken’s and the top-end is sweet with good amounts of detail. These and the Telefunken’s have different strengths depending on the headphones in use but both are certainly better than stock configuration. Prices are around $300/pair.

Balanced modality
With the balanced mode, the Schiit Gumby and Mjolnir really come to life with better detailing, separation and openness. The overall sound is markedly improved from the single-end outputs and is highly recommended to use. A couple of points to note is that less volume is needed to achieve the same output of sound so I would not advise to use these with high sensitivity devices as the headroom becomes much more restricted. Secondly, using the balanced topology, the sound characteristic does become slightly brighter so it is always good to consider the type of balanced cable to use to match with your gear.

Conclusion

As with their more budget-oriented models, the Schiit Gungnir Multibit and Mjolnir 2 combo have highly impressed me. Many would consider this an end-game setup and I would not blame them for doing so, as the stack not only illustrates music effortlessly but with articulacy too. The plethora of inputs and choices permit users to tweak the sound to their preference but the overall presentation is a tour-de-force for any audiophilic offering. Yes, micro-detail extraction could have been enhanced and perhaps Schiit could have included a different variety of stock tubes in their packaging but for what it is worth, the pair nestle comfortably on the top of their price-performance curves. In addition to this, the craftsmanship and overall aesthetics from Schiit are world-class with their use of brushed aluminum and minimalistic appeal. Without hesitation then, I would strongly recommend these for anyone wishing for top of the line quality for a fraction of the price. 

Unless otherwise indicated, this is a preview article for the featured product. A formal review may or may not follow in the future.