Astell&Kern Kann Ultra review
Astell&Kern Kann Ultra review
Astell&Kern Kann Ultra review

Astell&Kern Kann Ultra: The definition of hi-res

Astell&Kern Kann Ultra review

The highly anticipated Kann Ultra, the latest addition to Astell&Kern’s renowned line of Hi-Res players, is currently undergoing testing. This model marks the fifth iteration in the series, emphasizing maximum power within a compact body. Having previously reviewed the iconic debut Kann, as well as the more refined and equally captivating Kann Alpha, and the monitor-oriented Kann Max, I’ve covered nearly all the models in the series, with the exception of the Kann Cube.

Therefore, the announcement of the Kann Ultra immediately captured my interest. Achieving an impressive 16 Vrms output in a portable format is no small feat. Enthusiasts of full-size headphones requiring robust amplification will undoubtedly take notice. However, the player’s price tag of $1600 commands serious consideration. Let’s delve into whether it justifies its price point. Regardless of its MAX, ultra, extra, super, top, or Hi-End designation, what truly matters is its performance and audio quality.

Visual impressions


The Kann Ultra model arrives in a compact branded box, featuring a cardboard cover designed to mimic the texture of stone with veins. However, the included accessories are notably sparse, consisting only of two sets of protective films and a USB-C/USB-A charging cable. Surprisingly, there’s no protective cover included, which seems lacking given the device’s price segment. As a result, readers are advised to consider purchasing a separate case for the player. It’s somewhat disappointing, and one can’t help but hope that Astell&Kern will be more generous in the future. Such are the realities of audiophile products.



The Astell&Kern Kann Ultra exudes luxury with its refined design. While retaining the robustness characteristic of the Kann line, this model elevates itself with a premium touch. The aluminum body, adorned in Astro Gray color, exudes sophistication and feels comfortable in hand, thanks to its characteristic beveled lines and sharp edges.

The impeccable assembly is a hallmark of Astell&Kern products, and the Kann Ultra is no exception. Retaining the recognizable trapezoidal shape, the model stands out with its massive fluted volume wheel on the rear panel, embellished with concentric circles. This design element not only adds to the aesthetic appeal but also symbolizes the increased power of the device. It’s worth noting that compared to its predecessors, the Kann Ultra’s volume wheel is notably larger, emphasizing its enhanced capabilities.

In a playful comparison, the size of the volume control on the Kann Ultra indeed stands out when juxtaposed with that of the Astell&Kern Ultima SP3000. While perhaps unconventional, such comparisons add an element of whimsy to the evaluation of audio players.


As expected, the Astell&Kern Kann Ultra strikes a balance between compactness and functionality. Despite incorporating a robust amplification scheme, the device features a large 5.5-inch Full HD 1080×1920 screen. While this results in a relatively large body, it feels surprisingly light at 390 g, making it manageable for portable use. However, it may not fit into narrow pockets and would benefit from a protective case for travel.

In terms of control, the Kann Ultra offers a user-friendly interface with a touch screen and a start/lock key, supplemented by three physical buttons for track navigation. These buttons are tactically placed and easy to access, contributing to the player’s overall ease of use. Additionally, the design of the player is aesthetically pleasing, with power indicators adding a touch of sophistication. Overall, the Kann Ultra strikes a balance between power and portability, making it an appealing option for audiophiles on the go.


I recall that the predecessor of our protagonist, the Astell&Kern Kann Max, was somewhat restricted in terms of features, perhaps to avoid competing with the company’s older models. However, Kann Ultra breaks away from this tradition by offering a comprehensive range of features.

First and foremost, the model introduces a unique triple output mode with individually configured amplifier circuits and designs.

  • Headphone Out (headphone output 3.5 mm unbalanced, which also supports S/PDIF, and 4.4 mm balanced);
  • Pre-Out (pre-output with adjustable volume, which functions as a PRE AMP for connecting to external devices);
  • Line Out (line output with a fixed voltage and no change in volume, through which the sound comes directly from the DAC).


The array of connectors available on the Kann Ultra allows for its seamless integration as a full-fledged component within any audio system. Additionally, it offers an external sound card mode and can function as a receiver through its BT Sink feature.

Another notable feature is its exceptional power capabilities. With four levels of gain, the Kann Ultra is compatible with a wide range of headphones, from sensitive IEMs to power-hungry planar magnetic ones. Its low-impedance internal channels ensure a pristine, noise-free audio experience, while delivering an impressive 16 Vrms on the balanced output and 8 Vrms on the standard output, making it a true powerhouse for a portable device. While it does generate some heat under heavy load, it remains manageable. However, it’s crucial to match the power level to your headphones for optimal sound quality, as well as to experiment with the seven available digital filters, as they can significantly impact the sound profile.

The components within the Kann Ultra are of top-notch quality, with digital and analog parts being meticulously separated to prevent distortions. It features a flagship Dual ES9039MPRO DAC, supporting signal resolutions up to 32bit/768kHz and DSD512, along with an octa-core processor for enhanced performance. The firmware utilizes the user-friendly Crimson UI/UX, ensuring stable and swift operation, albeit with the drawback of a longer startup and shutdown time, a common issue with Astell&Kern players.

Additional features include dual-band Wi-Fi (2.4/5 GHz), Bluetooth 5.3 with aptX HD, HWA, and LDAC codecs, MQA streaming compatibility with various platforms, Roon Ready certification, DLNA support, and proprietary TERATON technologies like ALPHA, Digital Audio Remaster, Crossfeed, and AK File Drop. While the built-in memory is limited to 128 GB, the player includes a MicroSD card slot accommodating cards up to 1 TB in capacity.


The Astell&Kern Kann Ultra is equipped with an 8400 mAh battery, providing a stated operating time of up to 11 hours on a single charge. The inclusion of a PD3.0 fast charger ensures quick charging, with the player typically reaching full charge in approximately 3.5 hours. In my experience, the actual performance closely aligns with these specifications, and I have no complaints regarding battery life or charging speed.



Basic testing was conducted with a range of high-end headphones including the Focal Utopia, 64 Audio tia Fourte, Noble Audio Khan, Audeze LCD-2, and Dunu DK-3001 Pro.

My experience with the Astell&Kern Kann Ultra left me with overall positive impressions. While its presentation didn’t perfectly align with my personal preferences, particularly when compared to players from my collection, I found the experience enjoyable. The player particularly impressed with its excellent high frequencies and vocal reproduction. Listening to complex acoustic compositions was a pleasure, as the Kann Ultra excelled in processing the upper range of frequencies. The combination of theatrical holography and the expansive stage, enabled by its power reserve, further added to its appeal.

The Kann Ultra’s signature is characterized by a calm, cool, and voluminous sound with a hint of leisureliness. It delivers a melodious, weighty, and integrated sound with a delicate softness and harmony. Notes are smooth and thick, creating an atmospheric and aesthetic experience. The model achieves this effect through both general smoothing and enhanced low frequencies. Its good micro-detailing and clarity make it versatile across various genres and headphone choices. While listeners who prefer detailed separation may find it lacking, those who enjoy relaxed immersion in sound will appreciate its performance. Moreover, full-size headphone users will find its three-dimensional soundstage comparable to desktop setups.

Despite its serious swing, the Kann Ultra exhibits unexpected non-aggressiveness. Attacks are subdued, sub-bass is restrained, and energy is present but controlled. While speed and smoothness could be improved, this setting is not fatiguing over extended listening sessions and encourages thoughtful contemplation. Even for someone like me, who typically prefers a more energetic sound, I found the Kann Ultra’s presentation intriguing and engaging.



The Astell&Kern Kann Ultra delivers deep, massive, and thorough bass with sufficient density and necessary cohesion. While the variety of textures may be simplified, the bass remains impactful and well-aligned. Transitions are smooth, with mobile dynamics that avoid any deliberate swagger. While some may desire more impact, the bass harmoniously complements the overall sound profile.

Moving to the midrange, it is fused, natural, and smooth, offering a long, rounded sound with analog warmth. While small nuances may not be accentuated, they are easily discernible. Instruments lack emphasized contours but possess realistic physicality, contributing to an extremely large-scale soundstage. The palette of timbres is sweet and almost watercolor-like. Notably, the vocals shine with excellence, being expressive, clean, and emotionally engaging. However, there may be a desire for more speed and sharpened sharpness in the lower midrange, and some questions regarding the intelligibility of the second plan.

In the high frequencies, the Kann Ultra delivers transparent, defined, and controlled sound. The crystallinity, richness, and detail of the high frequencies are captivating, with strings and bells exhibiting embossed, sparkling, and iridescent qualities. There are no complaints regarding the wealth of overtones and resolution of the upper high frequency layers, making it reliable for live genres. The spectrum remains comfortable, avoiding any harshness or piercing frequencies. However, individuals sensitive to ringing should audition the Kann Ultra before making a purchase.



Your detailed description of the Astell&Kern Kann Ultra’s sound provides a clear understanding of its differences compared to competitors. Let’s delve into comparisons with several models.

Starting with the Astell&Kern Kann Alpha, owners of this model may consider an upgrade, especially in terms of resolution where the Kann Ultra shines. While the Kann Alpha impresses with its holography, clarity, and warm tonality, the Kann Ultra surpasses it in naturalness, stage scale, and power reserve. The Kann Alpha’s high frequencies are simplified compared to the Kann Ultra, which excels in this aspect, making it a significant advancement.

Next, the Astell&Kern Kann Max, previously a favorite in the line, offers a neutral, full-bodied sound with strong lows, detailed mids, and crisp highs. While it may lack the scale of the scene compared to the Kann Ultra, it impresses with its genre versatility and lack of ear-cutting accents or synthetics. In contrast, the Kann Ultra delivers more informatics and atmosphere, particularly notable in its spaciousness and upper frequencies, making it a compelling option for those seeking a more memorable listening experience.

Finally, the FiiO M17, which shares a similar price range with the Astell&Kern Kann Ultra, offers a magnificent stage, juicy sound, and excellent detail. While its natural timbres and neutral mid frequencies are commendable, some may find its treble to have a metallic ringing compared to the more refined highs of the Kann Ultra. Both models may lack some extravagance in their sound signature, but the FiiO M17 leans towards a more monitoring approach while the Kann Ultra offers a more entertaining and engaging sound. However, it’s worth noting that the Kann Ultra provides a greater volume margin for tight headphones compared to the FiiO M17. Ultimately, the choice between these models may depend on individual preferences and priorities in sound reproduction.


In conclusion, the Astell&Kern Kann Ultra stands out as a charismatic and compelling option in the world of Hi-Fi players. It offers flagship features, modern functionalities, user-friendly firmware, unparalleled power output, and a versatile triple output mode, making it a sought-after choice among audiophiles. However, it’s important to consider the device’s size and sonic presentation, which may cater to a specific audience.

For owners of high-quality full-size magneplanar headphones, the Kann Ultra is a must-consider portable source due to its ability to drive such demanding headphones with ease. For other audiophiles, I highly recommend exploring the Kann Ultra for listening, even if just for familiarity, as it represents a significant milestone in portable audio technology. Whether it becomes your go-to player or not, the Kann Ultra undoubtedly makes a lasting impression in the realm of Hi-Fi audio.

Astell&Kern Kann Ultra review
Astell&Kern Kann Ultra