Review of USB DAC and discrete headphone amplifier Schiit Jotunheim based on dual mono AK4490

The American company Schiit Audio is already familiar to our readers. This time we will review its interesting new product Jotunheim – USB DAC based on dual mono AK4490 and discrete headphone amplifier.

Schiit Jotunheim

The name Jotunheim comes from Scandinavian mythology, literally from Old Norse means “land of giants”. In Jotunheim lived fabulous creatures of giant growth and incredible power.
Jotunheim is indeed a fairly large representative of DACs Schiit Audio, especially when compared with inexpensive entry-level models such as Schiit Fulla 2. Jotunheim weighs 2.7 kg – against 200 g of Fulla 2. Supernatural abilities are also present here if we consider the ratio connectivity, sound quality and affordable price. The product turned out to be original and very interesting, American engineers did a good job.

Schiit Jotunheim

Schiit Jotunheim is a desktop DAC, at a price close to the initial price category, but with the capabilities of a much higher level. It will be interesting for connecting to equipment with balanced linear XLR-sockets or to balanced headphones. Normal headphones are also supported. There are also RCA inputs, but in this case exactly half of the electronic stuffing will be used. The whole point of the device is that a completely balanced discrete path is realized inside. There is no conversion to single ended on the input and vice versa on the output. Throughout the signal path, the circuit remains true balanced.
The main pride of the developers is the modular design of the product. The user can select three device options: basic (only the mode of analog line inputs and a headphone amplifier), complete with a phono stage or in combination with a dual mono AK4490 DAC card. We will review the last option – “DAC + headphone amplifier”, as the most popular and marketable.
Unlike the simpler Fulla 2, the UAC2 mode of the 6631A USB controller is already implemented here. It supports formats up to 32 bits 192 kHz, and for Windows there is a full-fledged ASIO driver. The only thing that does not exist is the DSD. The manufacturer briefly explains: there are too few records in the DSD format.

Schiit Jotunheim – price. Where is the best place to buy?

The recommended retail price for the Schiit Jotunheim in the US is $ 445.99. At this cost, you can order it on Amazon. I would not recommend ordering anywhere else except on Amazon. Since you are less likely to find cheaper, and if you do not take into account the fact that Amazon is probably the most reliable online store, it still very often provides free shipping.

Schiit Jotunheim Specifications

Operating frequency range 20 Hz – 20 kHz
(0.1 dB, 2 Hz – 700 kHz, -3 dB)
Coefficient of nonlinear distortion <0,001%
IMD <0,0015%, CCIR
Signal / Noise 109 dBA
Channel Separation > 70 dB, 20 Hz – 20 kHz
Impedance <0.1 Ω
Gain 6 to 14 dB, front panel switch
Maximum power with load impedance (balanced connection) 16 Ω: 7500 mW RMS/ channel
32 Ω: 5000 mW RMS/ channel
50 Ω: 3000 mW RMS/ channel
300 Ω: 900 mW RMS/ channel
600 Ω: 500 mW RMS/ channel
Maximum power with load impedance (unbalanced connection) 16 Ω: 2500 mW RMS/ channel
32 Ω: 1500mW RMS/ channel
50 Ω: 800 mW RMS/ channel
300 Ω: 350 mW RMS/ channel
600 Ω: 175 mW RMS/ channel
Inputs balanced XLR
unbalanced RCA
USB 2.0 DAC or RCA input with phono stage
Outputs 4-pin XLR balanced earphone
Earphone unbalanced TRS
linear balanced XLR
linear unbalanced RCA
DAC characteristics USB Controller: C-Media CM6631A
DAC: AK4490

  • Operating frequency range: 20 Hz-20 kHz (± 0.1 dB, 2 Hz-100 kHz, -3 dB)
  • Maximum output amplitude: 2.0V RMS
  • Coefficient of nonlinear distortion: <0.0015%, 20 Hz to 20 kHz
  • IMD: & lt; 0.002%, CCIR
  • Signal / Noise: & gt; 106 dB
Dimensions 229 × 152 × 51 mm
Weight 2.7 kg
Price $ 445.99

5 W at 32 Ohm load is the merit of a discrete circuit and built-in powerful linear PSU. Why do we need such power? This is mainly required for low-sensitivity headphones.
The claimed impedance of the headphone amplifier is <0.1 Ohm, that is practically 0. What does this mean and why is it important? Load, especially low-resistance, should be well electrically damped, then the membrane will not uncontrollably walk at frequencies of mechanical resonances. With a correct amplifier, it may seem that the bass is subjectively less, but in fact it becomes more pure. And this will be a correct even AFC, if measured by a microphone. You can compare with any amplifier with a high output impedance and some capricious headphones. The biggest problems will be with the balanced armature emitters: this is the curvature of the AFC to 12 dB at the midrange, and an increase in distortion. But even with a high-impedance HD600, you can also get an unwanted rise to LF and an increase in distortion. There is a theory that high-impedance headphones require a special high-impedance output of the amplifier. There are no technical prerequisites for it. Most likely, such an opinion appeared as a result of a confluence of circumstances, when the curvature of the amplitude response from the amplifier went to the headphones for good. But it’s better to simply avoid using strange equipment.

Schiit Jotunheim

The presence of XLR-inputs is unusual. And RCA-, XLR- and USB-sources can be selected using switches on the front panel. Therefore, inside there is a full-fledged choice of signal sources, which can be convenient. From the outputs you can send a signal to any equipment without problems. The volume control also affects the line outputs, so Jotunheim can be used as a preamplifier.

Schiit Jotunheim
The second hardware switch is used to select the gain level (low-high). This is very useful, because in the initial positions of the volume control there is often a channel imbalance. The volume of the left and right channels with analog adjustment will be different – this is almost inevitable in high power amplifiers. By setting a lower gain, you transfer the regulator to an area where there is no such problem.
Schiit Jotunheim
The metal case serves as a solid base for mounting a large internal PCB. The manufacturer could separate the nodes and place them on separate boards, but it would be necessary to make pads and lay wires that, with powerful power, can be a source of interference. Probably, therefore, it was decided to implement the device on one board. Only a digital card with a USB controller and a DAC is made separate and replaceable.

Linear power supply has a huge cans. The manufacturer here made his choice in favor of classics. Although impulse power supplies, with proper developer qualifications, are now practically inferior in quality to linear.

Schiit Jotunheim
Of course, the most interesting is a discrete headphone amplifier. The manufacturer says that the development of this model took in the amount of 3 years. The main feature of the circuit is the separate amplification of the cold and hot signals of the balanced line along the entire path. Also, the circuit does not use electrolytes to remove the DC bias so as not to spoil the sound. (Those two small op-amp can be seen in the picture, just perform the function of eliminating the constant component and, in fact, do not participate in the formation of sound.The path remains completely discrete.
According to our measurements, a signal-to-noise ratio of 120 dB and a 0.0004% distortion is obtained from the line output. Passport parameters of the manufacturer are much lower, which is explained by passport measurements at a lower level of the output signal.
Schiit Jotunheim
The removable DAC board does not use electrolytes and op-amps, as the manufacturer promised. Three quartz oscillators allow the use of multiple 44 kHz frequencies to reduce jitter. The use of German Wima capacitors should have a beneficial effect on sound.

ASIO Diagnostics

Device: ASIO for C-Media USB Device
Input channels: 0
Output channels: 2
Input latency: 2288
Output latency: 4752
Min buffer size: 2200
Max buffer size: 2200
Preferred buffer size: 2200
Granularity: 0
ASIOOutputReady — not supported
Sample rate:
8000 Hz — not supported
11025 Hz — not supported
16000 Hz — not supported
22050 Hz — not supported
32000 Hz — not supported
44100 Hz — supported
48000 Hz — supported
88200 Hz — supported
96000 Hz — supported
176400 Hz — supported
192000 Hz — supported
352800 Hz — not supported
384000 Hz — not supported
Input channels:
Output channels:
channel: 0 (SPKOut00_00 ch) — Int32LSB
channel: 1 (SPKOut00_01 ch) — Int32LSB

Schiit Jotunheim RightMark Audio Analyzer test report

Testing device Schiit Jotunheim
Sampling mode 24-bit, 44 kHz
Testing chain External loopback (line-out – line-in)
RMAA Version 6.4.1 PRO
20 Hz – 20 kHz filter ON
Normalize amplitude ON
Level change 0.6 dB / 0.6 dB
Mono mode OFF
Calibration singal, Hz 1000
Polarity correct/correct


Frequency response (from 40 Hz to 15 kHz), dB
+0.04, -0.30
Very good
Noise level, dB (A)
Dynamic range, dB (A)
THD, %
THD + Noise, dB (A)
IMD + Noise, %
Stereo crosstalk, dB
IMD at 10 kHz, %
General performance

Frequency response

Schiit Jotunheim

From 20 Hz to 20 kHz, dB
-0.54, +0.04
-0.59, +0.04
From 40 Hz to 15 kHz, dB
-0.30, +0.04
-0.32, +0.04

Noise level

Schiit Jotunheim

RMS power, dB
RMS power (A-weighted), dB
Peak level, dB FS
DC offset, %

Dynamic range

Schiit Jotunheim

Dynamic range, dB
Dynamic range (A-weighted), dB
DC offset, %

THD + Noise (at -3 dB FS)

Schiit Jotunheim

THD, %
THD + Noise, %
THD + Noise (A-weighted), %

Intermodulation distortion

Schiit Jotunheim

IMD + Noise, %
IMD + Noise (A-weighted), %

Stereo crosstalk

Schiit Jotunheim

Crosstalk at 100 Hz, dB
Crosstalk at 1000 Hz, dB
Crosstalk at 10000 Hz, dB

IMD (swept tones)

Schiit Jotunheim

IMD + Noise at 5000 Hz,
IMD + Noise at 10000 Hz,
IMD + Noise at 15000 Hz,

The results of testing the device are excellent. A little interference on the spectrum is caused by the features of the test bench.

Listening and conclusions

The sound of Schiit Jotunheim is very good. It can not be said that the DAC function here is a free bonus and is made on the principle “just to have a USB connector” – this is found in some headphone amplifiers. Schiit Jotunheim is a full-featured DAC and a full-featured powerful (2 × 5W) headphone amplifier.
The sound of Jotunheim is dynamic, there is no sign of sluggishness or lack of HF. At the same time there are no accents on any range, high frequencies do not tire. No distortion or color is heard. Sound detail is on top. The bass is very good, it’s enough here. Feels good damping. The sound can be called correct. In comparison with other devices of higher price category, Jotunheim looks interesting and competitive. In general, you can expect that the sound will appeal to the vast majority of listeners. Other sound sources can be connected to the balanced input and you can use Jotunheim only as a powerful high-quality headphone amplifier.
We can only wish the manufacturer to make more removable boards, with different versions of dual mono DACs. It would be interesting to see, for example, a board with AK4497, which should be compatible with the current C-Media firmware.

Video review

Schiit Jotunheim Review - USB DAC based on dual mono AK4490
Article Name
Schiit Jotunheim Review - USB DAC based on dual mono AK4490
Detail review and test in RMAA of Schiit Jotunheim USB DAC and discrete headphone amplifier Schiit Jotunheim based on dual mono AK4490. Video. Best price.

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