Astell & Kern Kann Ultra Portable Music Player

Astell & Kern

Astell & Kern Kann Ultra Portable Music Player

Astell & Kern Kann Ultra Portable Music Player
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Fueling Your Sound

The KANN series is adored by audiophiles all over the world for its performance that focuses on ultra-high output and clear sound.

KANN ULTRA, the 5th product in the KANN series, continues the success of the KANN series by providing the highest output of any Astell&Kern player, the inclusion of Triple Output Sound, and an optimised processor and UI/UX to make it even easier to enjoy clear sound performance.

Kann Ultra standing with headphones plugged in and in front of the box

With four Gain Modes that provides up to 16Vrms of desktop HiFi level output and sound, and ES9039MPRO Dual DAC chips, KANN ULTRA perfectly powers many of today's headphones with high resolution. A separate Pre/Line Out allow users to enjoy the sound with a variety of different devices.


  • Triple Output Mode Featuring Separately Configured Circuit and Amplifier Designs
  • Next-generation Octa-Core processors with significant high-performance improvements
  • Supports 4 preset gain settings with ultra-high output up to 16Vrms (Headphone Out)
  • Equipped with ES9039MPRO Dual DACs
  • Features Digital Audio Remaster (DAR) technology
  • Supports playback up to 32bit/768kHz, Native DSD512
  • Features Astell&Kern's unique TERATON ALPHA technology
  • Battery 8,400 mAh (up to 11 hours of playback)

Triple Output, Triple Sound

KANN ULTRA features a Triple Output Mode that allows you to enjoy Astell&Kern's perfectly prepared sound when connected to demanding headphones, highly detailed IEMs, and external devices.

Kann Ultra laying face down with a headphone cable plugged in

Instead of simply separating the output ports, Astell&Kern's Teraton Alpha technology allows for separate amplifier/sound design for the Headphone Out and Line/Pre-Out ports to provide the optimal sound for each port. 
Complete your powerful Head-Fi system even on portable devices with the KANN ULTRA with Triple Output.

Headphone Out

The port features 4 preset gain settings and ultra-high output of up to 16Vrms. The headphone port is designed to perfectly run demanding headphones with high impedance using only the player with no external AMP.


Select Pre-Out mode on the Pre/Line Out port to output sound to an external amplifier or audio device.

Line Out

Select Line Out mode on the Pre/Line Out port to output sound that is optimized when connected to external devices.

Gain Levels And Outputs Up to 16Vrms for The Perfect Head-Fi

To run the most sophisticated IEMs and headphones, a DAP needs to be able to fully deliver an output that matches the characteristics of the receiver.

KANN ULTRA features 4 preset gain settings up to 16Vrms, the most powerful output of any Astell&Kern player, to optimally run the many IEMs and headphones available today.

Kann Ultra laying face-down showing the connection options at the top and the dial.

The current-handling capability of the output port has been increased to reliably run devices of different impedances at the gain Level setting, and the AMPs have been separated into Balanced and Unbalanced to optimise currents and reduce noise for the best possible sound.

On top of providing the most powerful output, KANN ULTRA features a larger 5.5-inch screen and improved grip compared to KANN CUBE, which was popular for its high output versatility. Weight of the KANN ULTRA has been significantly reduced to 390 grams.

Teraton Alpha, The Essence of A&K Audio Technologies

From an ultra-high output that can run even the most delicate headphones, to the Triple Output design, and the complex amplifier design with minimal noise in a compact portable audio player, this would all not have been possible without AK's Ultimate Sound Solution, TERATON ALPHA. Astell&Kern has taken the TERATON ALPHA to the next level with its know-how in noise reduction at ultra-high power, acquired from its predecessors such as the KANN MAX and the CA1000 series.

TERATON ALPHA, engineered through continuous research, is Astell&Kern's unique technology that has been designed to produce audio playback that is as close to the original sound through effective power noise removal, efficient power management and unwavering amplification, and a fully converted audio output interface.

Upgraded Sound, the Newest ESS Flagship DAC

The KANN ULTRA is designed with dual ES9039MPRO DACs, the newest flagship DAC from ESS, to deliver richer and more expansive sounds that exceed your expectations.

The ES9039MPRO is an updated ES9039PRO model that has a built-in stereo hardware MQA renderer. It has even more advanced modulation than the existing flagship DAC to reduce power consumption, noise and distortions inside the DAC for enhanced audio performance.

Astell&Kern has redesigned the AMP BLOCK to ensure that the clear, high-resolution sound of the ES9039MPRO is clearly expressed through every port of the Triple Output, and each output's characteristics show its own advanced performance.

Kann Ultra at an angle viewed from the back against a black background

Incredible User Experience with Next-Generation Octa-Core Processors

KANN ULTRA is the first to feature the next-gen Octa-Core processors with significant performance improvements, allowing you to enjoy KANN ULTRA's incredible sound performance with faster system speeds and a 4th generation UI/UX that flows faster and smoother.

The audio circuit area is physically separated from the processor area, which includes the CPU, memory, and wireless communication components, and is equipped with a dedicated shield can to minimise the heat and noise generated by the processor.

Crimson User Interface, A Music-Only Player

KANN ULTRA features a Crimson-themed UI/UX for the first time in the KANN series, making it a "Player for Music" that leaves an impression in the process and experience of listening to music.

The Crimson UX/UI is designed so that users can quickly browse music categories and re-discover songs within their music library.

A&K also added an easy album art search function so that users can re-discover the joy of viewing and interacting with music album art whilst listening to their music.

Kann Ultra laying face down beside some earphones

The crimson theme focuses on edge, simplicity, and dark mode keywords.  The colour theme of black with red highlights lowers visual fatigue and offers intuitive user experiences, and includes many other improvements 
to the device’s user-friendliness of streaming app services, artist view, album sorting, and album art search function.

Immerse yourself in music with Crimson UX/UI.

Sound Design by DAC Filter

With the KANN ULTRA, you can pick and choose from seven DAC filters to create your own sound style.  Design your own sound with the seven DAC filters.

Digital Audio Remaster Technology for Even More Vivid Original Sound

The KANN ULTRA is equipped with Digital Audio Remaster(DAR) technology, which was developed to deliver fine sound at higher sample rates.

DAR technology is developed to upsample the sample rate of the sound source being played to go beyond the limits of the source format.

The high sample rate allows more refined playback and offers delicate and analogue-like original sound, helping you to enjoy the richness of the original sound, subtle differences in the nuance of the music and full-bodied sounds at a higher level.

Crossfeed, Speaker effect when listening through headphones

In a headphone environment in which the left and right channels are clearly separated, ear fatigue may increase during prolonged listening. The moment you turn on Crossfeed, the experience of crisp, but comfortable sound begins.

Crossfeed mixes parts of the original signal from one channel and sends that signal to the opposite channel with a time difference to center the sound image.

Through the use of detailed settings such as Shelf Cutoff, Shelf Gain, and Mixer Level, you can set the level of crossfeed according to your listening preferences.

A pair of A&K Kann Ultra Music Players.  One face down, one face up

Real-Time Information Confirmed by Light

The LED lights on the volume wheel visually represent the power of the KANN ULTRA and show the volume level or the Bit Depth of the currently playing song.

Supports Native DSD512, 32bit/768kHz

KANN ULTRA supports playback of Native DSD512 and up to 32bit/768kHz PCM audio with Astell&Kern’s excellent audio technology, allowing you to fully enjoy your favourite music.

AK File Drop to enjoy wireless transfers

The new AK File Drop function in the KANN ULTRA makes file transfers easier and more convenient. Using AK File Drop, you can freely transfer files wirelessly through a PC, smartphone, or FTP program located on the same network. Music file management is now possible with a cableless, wireless solution.

Adoption of 5.5-inch Full HD Display

Experience the KANN ULTRA more vividly and comfortably with a wide 5.5-inch, large-screen Full HD display.

ReplayGain Automatically and Uniformly Adjusts Playback Volume

Replay Gain automatically adjusts the loudness of each song to prevent large fluctuations of volume between different musical tracks. Now, you can enjoy your own playlists seamlessly, at a consistent volume using the Replay Gain feature on the KANN ULTRA. 
* ReplayGain supports up to 24-bit/192 kHz sound sources.

Kann Ultra standing with a pair of headphones on a stand to the right of the image.

ROON ARC App Supported

KANN ULTRA supports the Roon Arc App through Open Service. Roon ARC gives you remote access to your complete, personalized library of artists, albums, playlists, and tags – supported by rich, in-depth metadata that inspires you to discover more about the music you love.

Wireless HiFi Sound Through BT Sink

BT Sink function connects the KANN ULTRA to an external device via Bluetooth, similar to connecting a smartphone with a BT speaker. Music from an external device, such as a smartphone can now be played back in high-quality on the KANN ULTRA using the BT Sink function.


The design concept of KANN ULTRA is "Forceful Impact". 
The design is an over-scaled volume wheel knob that has been slammed and embedded into the body of the KANN to visually represent its more powerful performance than its predecessor. With the KANN ULTRA, A&K continued the design identity of the KANN series, which emphasises the hexagonal columnar body while still keeping it visible.

A&K minimised the visible parting lines and designed the wheel protectors so that the outer edge of the body where the volume wheel sits naturally acts as a protector and improves usability. These elements emphasise the bold mass of the KANN ULTRA, representing primal power through a solid chunk of metal.

A&K applied decorative parts that connect with the serrated pattern on the volume wheel knob to make the wheel visually larger and maintain a balance with the massive body, while expressing the powerful performance of the KANN ULTRA. Additionally, the hairline spin decoration applied to the rear of the wheel acts as a delicate detail element along with the lettering engraving, showing the volume wheel knob strongly embedded into the BODY.

Due to the increased size, A&K have redesigned the orientation of the volume wheel to accommodate usage in different environments, such as on the desk, or held in your hand.

  • Model: KANN ULTRA
  • Body Colour: Astro Gray
  • Body Material: Aluminum
  • Display: 5.5inch HD 1080 x 1920 touch screen
  • Supported Audio Formats: WAV, FLAC, WMA, MP3, OGG, APE, AAC, ALAC, AIFF, DFF, DSF, MQA
  • Sample Rate: 
    • PCM : 8kHz ~ 768kHz (8/16/24/32bits per Sample)
    • DSD Native: DSD64(1bit 2.8MHz), Stereo / DSD128(1bit 5.6MHz), Stereo
    • DSD256(1bit 11.2MHz), Stereo / DSD512(1bit 22.4MHz), Stereo
  • Output Level - HEADPHONE OUT:
    • [Low Gain] Unbalanced 2Vrms │ Balanced 4Vrms (Condition No Load)
    • [Mid Gain]Unbalanced 4Vrms │ Balanced 8Vrms (Condition No Load)
    • [High Gain]Unbalanced 6Vrms │ Balanced 12Vrms (Condition No Load)
    • [Super Gain]Unbalanced 8Vrms │ Balanced 16Vrms (Condition No Load)
  • Output Level - PRE · LINE OUT: Unbalanced 2Vrms │ Balanced 4Vrms (Condition No Load)
  • CPU: Octa-core
  • DAC: ES9039MPRO x2
  • Decoding: Support up to 32bit/768kHz Bit-to-Bit Playback
  • Input: USB Type-C input (for charging & PC & MAC)
  • Outputs - HEADPHONE OUT: 3.5mm(Unbalanced Out, Optical Out), 4.4mm (Balanced Out, only 5-pole supported)
  • Outputs - PRE · LINE OUT: 3.5mm(Unbalanced Out), 4.4mm (Balanced Out, only 5-pole supported)
  • WiFi: 802.11 a/b/g/n/ac (2.4/5GHz)
  • Bluetooth: V5.3 (A2DP, AVRCP, Qualcomm® aptX™-HD, LDAC, LHDC)
  • Dimensions: 3.24” (82.4mm)[W] x 5.55” (141.1mm)[H] x 0.96” (24.4mm)[D]
  • Weight: About 13.75oz (390g)
  • Feature Enhancements: Firmware upgrade supported (OTA)
  • Operating Temperature: 0℃ ~ + 40℃ (32℉~ 104℉)

AUDIO specifications

  • Frequency Response HEADPHONE OUT: 
    • ±0.006dB (Condition : 20Hz~20kHz) Unbalanced │ ±0.004dB (Condition : 20Hz~20kHz) Balanced
    • ±0.016dB (Condition : 20Hz~70kHz) Unbalanced │ ±0.020dB (Condition : 20Hz~70kHz) Balanced
  • Frequency Response PRE OUT:
    • ±0.022dB (Condition : 20Hz~20kHz) Unbalanced │ ±0.023dB (Condition : 20Hz~20kHz) Balanced
    • ±0.023dB (Condition : 20Hz~70kHz) Unbalanced │ ±0.023dB (Condition : 20Hz~70kHz) Balanced
  • Frequency Response LINE OUT:
    • ±0.002dB (Condition : 20Hz~20kHz) Unbalanced │ ±0.002dB (Condition : 20Hz~20kHz) Balanced
    • ±0.007dB (Condition : 20Hz~70kHz) Unbalanced │ ±0.006dB (Condition : 20Hz~70kHz) Balanced
  • S/N HEADPHONE OUT: 115dB @ 1kHz, Unbalanced │ 119dB @ 1kHz, Balanced
  • S/N PRE OUT: 110dB @ 1kHz, Unbalanced │ 126dB @ 1kHz, Balanced
  • S/N LINE OUT: 110dB @ 1kHz, Unbalanced │ 125dB @ 1kHz, Balanced
  • Crosstalk HEADPHONE OUT: 134dB @ 1kHz, Unbalanced │ 140dB @ 1kHz, Balanced
  • Crosstalk PRE OUT: 128dB @ 1kHz, Unbalanced │ 128dB @ 1kHz, Balanced
  • Crosstalk LINE OUT: 129dB @ 1kHz, Unbalanced │ 121dB @ 1kHz, Balanced
  • THD+N HEADPHONE OUT: 0.0004% @ 1kHz, Unbalanced │ 0.0004% @ 1kHz, Balanced
  • THD+N PRE OUT: 0.0012% @ 1kHz, Unbalanced │ 0.0005% @ 1kHz, Balanced
  • THD+N LINE OUT: 0.0013% @ 1kHz, Unbalanced │ 0.0005% @ 1kHz, Balanced
  • IMD SMPTE HEADPHONE OUT: 0.0006% 800Hz 10kHz (4:1) Unbalanced │0.0006% 800Hz 10kHz (4:1) Balanced
  • IMD SMPTE PRE OUT: 0.0006% 800Hz 10kHz (4:1) Unbalanced │0.0006% 800Hz 10kHz (4:1) Balanced
  • IMD SMPTE LINE OUT: 0.0006% 800Hz 10kHz (4:1) Unbalanced │0.0006% 800Hz 10kHz (4:1) Balanced
  • Output Impedance HEADPHONE OUT: Unbalanced Out 3.5mm (1ohm) │ Balanced Out 4.4mm (1.3ohm)
  • Output Impedance PRE OUT: Unbalanced Out 3.5mm (3.5ohm) │ Balanced Out 4.4mm (5.7ohm)
  • Output Impedance LINE OUT: Unbalanced Out 3.5mm (6.5ohm) │ Balanced Out 4.4mm (10.7ohm)

Clock Source

  • Clock Jitter: 25pS (Typ)
  • Reference Clock Jitter: 200 Femto Seconds

Storage Capacity

  • Built-in Memory: 128GB [NAND]
  • External Memory: microSD x1 (Max. 1TB)


  • Capacity: 8,400mAh 3.8V Li-Polymer
  • Charge Time: about 3.5 hours (PD 3.0 Charger)
  • Playback Time: about 11 hours (Standard: FLAC, 16bit, 44.1kHz, Vol.50, LCD Off, Low Gain)

Overall Rating