Astell&Kern KANN MAX Digital Audio Player Review

South Korean audio manufacturer Astell&Kern has an extremely comprehensive line-up of Digital Audio Players (or “DAPs”) across their portfolio, and it might be tricky to work out where the best jumping-in point for you might be if you’re looking to upgrade your portable audio world with one of their digital devices. While all A&K products are intended for different end-users, different applications, and each provides a different take on the “Astell&Kern sound”, there are two things most audiophiles can agree on: Astell&Kern DAPs a) sound great, and b) look like nothing else on the market.

Just when you thought you’d worked out which product sits where in the Astell&Kern portfolio, they’ve gone and added a brand new member to the “KANN” family of DAPs: meet the new Astell&Kern KANN MAX Digital Audio Player, which is available now for $2199 at Addicted To Audio. Astell&Kern has built upon the success of their highly-regarded KANN ALPHA Digital Audio Player, and has managed to do two seemingly incongruent things with the release of the KANN MAX: they’ve made it even more powerful, and they’ve made it even smaller. 

The Astell&Kern KANN MAX: a new head-fi “Hot Hatch” 

You can keep your supercars, V8’s and convertibles - I’ve always been a fan of “hot hatches”. For me, there’s no better recipe for motoring fun than stuffing a potent engine into a lightweight, compact chassis that’s been tinkered-with and tuned to create a great-handling, quick-off-the-mark car that puts far more ostentatious vehicles to shame. And the best part? You can be pretty “incognito” when you’re driving around in a hot hatch. Most commuters are generally pretty oblivious to just how potent your whip is, as they can easily pass for their more “pedestrian” donor base-model. Unless, of course, you know your cars and recognise that that “GTi” or “R” badge and lower profile tyres mean that there’s a little something-something extra lurking under the hood in your “sleeper” (that’s the part when you give them the nod). 

The ethos behind the KANN series is driven by Astell&Kern’s vision to create ”a product line that emphasizes performance with a sense of weight”. The KANN MAX, the fourth entrant in the series, certainly embodies this philosophy. With a stunning 15Vrms of power available with four levels of adjustable gain, it promises to be a match for IEMs and power-hungry headphones alike. And with its robust, all brushed-aluminium chassis and sculpted exterior it not only looks like yet another evolution of Astell&Kern’s distinctive design language, the KANN MAX looks like it means business - it definitely oozes “hot hatch” vibes from the moment you take it out of the box and weigh-up its solid heft sitting menacingly within the palm of your hand. 

Four levels of analogue power

It’s a necessary evil in audio design that noise and distortion increase with volume, and so when designing a device capable of outputting a maximum 15Vrms, Astell&Kern carefully design the circuits in the KANN MAX to ensure a low noise-floor, even when in its highest output setting. 

KANN MAX owners can choose between four different gain modes to best match the IEMs or headphones they’re listening to, to ensure the right level of power and volume precision can be used under any circumstances. Helpfully, Astell&Kern have implemented a feature whereby the device’s maximum volume is automatically limited when changing amp modes to protect your hearing should you accidentally forget that you were listening to your HIFIMAN HE-6 and then swapped over to a pair of balanced armature IEMs! The maximum voltage level for each of the four modes are as follows:

  • [Low] Unbalanced 2Vrms / Balanced 4Vrms (Condition No Load),
  • [Mid] Unbalanced 4Vrms / Balanced 8Vrms (Condition No Load),
  • [High] Unbalanced 6Vrms / Balanced 12Vrms (Condition No Load),
  • [Super] Unbalanced 8Vrms / Balanced 15Vrms (Condition No Load)

Quad DAC implementation

The KANN MAX features no fewer than four ES9038Q2M DAC chips, the first time a “Quad DAC” implementation has been used in the KANN series. Each individual DAC chip is responsible for feeding four individual amp channels, and have been integrated with the KANN MAX’s circuit design to help provide it with a faithful, low-distortion signal. Astell&Kern’s proprietary “TERATON ALPHA Sound Solution” technology further helps remove noise from the power supply, and ensure that the amplification and power consumption remains optimally efficient at the point in the circuit where the digital-to-analogue conversion occurs. 

The four ESS DACs make the KANN MAX capable of decoding PCM files up to a 32-bit/768kHz sample rate, DSD up to 512, as well as MQA x8. Eight separate DAC filter settings can be chosen to suit your listening preference (in PCM only up to 24-bit/192kHz), although from my experience they don’t really make any perceivable difference to your day-to-day listening. 

Wireless + streaming capabilities

As well as playback of locally-stored files, the KANN MAX gives you the option of choosing from a cornucopia of streaming services with the ability to stream wirelessly via wifi, or Bluetooth 5.0. The KANN MAX only supports single-band 2.4GHz wifi, and allows you to access a number of audio streaming apps which can either be downloaded through its customised Android operating system, or “side-loaded” by installing the .APK file on its hard-drive when connected to a Mac/PC. Wifi connectivity also makes it possible to receive future over-air firmware updates when they become available, as well as using the “AK File Drop” function which makes it easy to drop/drag files onto the KANN MAX’s onboard storage via an FTP server. 

The KANN MAX also includes Bluetooth 5.0 streaming functionality, compatible with the higher-res aptX-HD and LDAC codecs for greater wireless fidelity. The KANN MAX can be used as a  Bluetooth “receiver” through its “BT Sink” feature, meaning you can send an audio signal to the KANN MAX from a device such as your smartphone.

Alternately, the KANN MAX can also be used as a Bluetooth source, or “transmitter”, making it possible to access all the onboard high-res files and streaming services and play them back on a suitably-appropriate pair of wireless headphones or IEMs, such as Astell&Kern’s own UW100 True Wireless Earphones, which paired with the KANN MAX seamlessly for an enjoyable 24-bit listening experience that was both interruption-free, and free of wires!

Astell&Kern KANN MAX design and form-factor 

The KANN MAX is at once an Astell&Kern DAP as well as a member of their “KANN” family at first glance - it also looks far too small to be capable of a whole 15Vrms of headphone-pushing power, weighing a mere 3-5 grams, and taking up about the same space as a deck of cards - 68.3mm x 117mm x 23.6mm, to be precise. It’s definitely a pretty small device as DAPs go, and only its thickness really gives you any hint of the power that it can unleash. You can easily pop it into your jeans pocket, although its pointed aluminium corners may make that a little uncomfortable! 

The KANN MAX’s sides, rear, and bottom fascias are made from a nice-looking, dark brushed aluminium, with the device’s name proudly emblazoned in a CNC-embossed logo on the back. The top side of the KANN MAX sports a mirror-finished sheen, with 2.5mm balanced, 4.4mm balanced and 3.5mm single-ended headphone jacks as well as the device’s power button (which also wakes/sleeps the display). 

Three tactile buttons are included on the KANN MAX’s left-hand side which manage standard playback functions (track reverse, play/pause, and track forward). 

Like its relatives in the Astell&Kern DAP line-up, the KANN MAX sports a knurled machine volume wheel which is free-spinning, and has a nice solid “click” when you spin through the 150 increments of volume on the device. Astell&Kern has given the KANN MAX an analogue volume control, to ensure no loss of audio quality and it provides perfectly-matched levels between both channels all the way down to “01” with sensitive IEMs.

A subtle LED ring sits underneath the volume wheel and changes colour alternately between red, green, and purple to signify that either 16-bit, 24-bit, 32-bit, or DSD files are playing. Alternately, you can reconfigure this through the KANN MAX’s settings to change in intensity depending on the current level of volume. 

The KANN MAX only has one digital input on the bottom panel, a USB-c connection which is used for charging the device, transferring data onto its 64Gb internal hard-drive (or MicroSD card, inserted via a slot next to the USB connection), or for using the KANN MAX as an external USB DAC/amp when connected to a source device like a laptop or smartphone. 

Physically-speaking, the KANN MAX is a pretty sleek and simple device, with only four physical buttons plus a volume wheel - the rest of the device’s funtions are managed through the 4.1-inch 720 x 1280 colour touch-screen. It’s not quite as vivid and detailed as other A&K DAPs by virtue of its smaller screen real-estate, but the KANN MAX’s screen is reasonably bright, has good colours and album cover art looks generally pretty good. 

Astell&Kern has designed a matching leather Astell&Kern KANN MAX Case to perfectly contour to the KANN MAX’s unique abstract hexagonal design, with black, tan, and teal colours for you to choose from to match your everyday carry aesthetic. If you plan on taking your new KANN MAX with you on the go, I’d say it’s probably a “must have” to avoid both damage to your nice new DAP as well as yourself or other items - it is pretty solid and sharp! 

KANN MAX User Experience  

Like all Astell&Kern DAPs, the KANN MAX runs a streamlined version of Android, and its operating system is powered by a Quad-core processor. Navigating the device is a pretty straightforward affair, and if you’ve used any other Astell&Kern device you’ll be up and running immediately. A “home” button on the button on the screen take you back to the home playback screen; a drop-down menu (accessible via the “A” logo in the top left-hand corner) grants you access to the key local playback features, plus a link to the “Services” menu whereby you can install and access your streaming app of choice. In my case, I downloaded and installed Qobuz after connecting to my home wifi, and after signing in my albums and playlists were all instantly accessible - nice. 

The KANN MAX’s key device settings can be found by “swiping” down from the top of the screen, and this is where you manage wifi and Bluetooth connections, various accessibility functions, USB protocol, as well as Astell&Kern’s familiar EQ settings, which can be dialled-in pretty accurately should you need to give your headphones or IEMs a little “tickling” to their frequency-response. Further device tweaks, including the all-important “AMP” gain settings can be found a little deeper in the settings menus - I would have preferred to have access to the gain settings made a little easier in the initial swipe-down menu as I tend to swap around headphones and IEMs quite a bit, but it’s not really a big deal. 

The “Android-lite” UI isn’t exactly as snappy as you’d be used to with your smartphone, but it’s generally pretty responsive and is entirely fit-for-purpose when it comes to selecting music and and managing day-to-day device settings. Wifi performance does drop off noticeably compared to other devices when moving around indoors, although I was able to manage a stable connection with CD-quality 44.1kHz in every room of my home. I did experience the odd drop-out when moving-up to 192kHz Qobuz streams, so it’s probably best to be within eyesight of a router if you’re planning on doing some serious streaming time. 

Astell&Kern estimate that the KANN MAX ought to be good for about 13.5 hours’-worth of playback time with a full charge of the 5,600mAh battery, which takes about 3.5 hours to charge with a fast charger. I didn’t exactly have 13.5 hours free to perform a battery torture test, but I managed a full eight hour work day of almost non-stop listening with about 15% of charge left with full-sized headphones - your mileage may vary depending on what you’re listening to. I will also note that the KANN MAX does get mildly warm after a couple of hours of listening. 

The KANN MAX also includes other handy audio-tweaking features such as digital balance control, Astell&Kern’s “ReplayGain”, which helps to level volume across different tracks to a similar level (useful if you’re in a playlist), plus a pretty useful and effective crossfeed system, which lets you control the amount of shelf cutoff and gain between channels, as well as options to choose from “C-Moy” and “J-Meter” presets. 

Seeing as the KANN MAX is a pretty formidable all-in-one DAC/amp combo in terms of its power output and digital conversion talents, you can also easily use it as a “desktop” device when configured to USB DAC mode. Simply connect your KANN MAX to your smartphone or computer via a USB-c cable, set it as your output device, and you then simply use its wheel to control your volume level while you manage playback from your source device. I set the KANN MAX as an output device from my Macbook Roon core, and had it lying face-down next to my keyboard for easy access to the volume wheel, and this worked brilliantly as a portable and powerful DAC/amp solution. Or, just set the KANN MAX’s volume to “line out”, and use it as either a single-ended or balance DAC via the 3.5mm or 4.4mm headphone jacks, and instantly add a Quad ES9038Q2M digital-decoder to your audio chain, with the ability to playback thousands of files stored on the device, or streamed online. 

Listening to the KANN MAX

Seeing as the KANN MAX has four different gain settings, it felt prudent to test it out under four different conditions with suitably-matched IEMs and headphones, each which require increasing levels of power to operate at their best. Across the board, the KANN MAX lived up to my expectations of an Astell&Kern device in terms of sound quality and performance - it’s a detailed and lively device, with a slightly more “playful” take on neutral than a dead-flat device. The KANN MAX’s soundstage presentation is impressive, with individual tracks well-sorted across a left-to-right canvas, and it manages to convey analogue tones and textures in a pretty convincing and organic way. There are no errant frequency response dips/troughs apparent anywhere, and those four ES9038Q2M DACs provide as transparent a window into a track as you’ll find. 

First testing the device with the 8-ohm/106dB 64 Audio 18s Universal In-Ear Earphones, the KANN MAX proved to have a dead-silent background when using both the 3.5mm single-ended and 2.5mm balanced inputs. Being a very sensitive IEM, the “Low” amp mode was more than sufficient here - I had the volume set to 60/150 in single-ended mode, and stepped it down to 45/150 when using a 2.5mm cable. I felt like blasting through a bit of psychedelic rock, and so I lined up a few Oh Sees albums that I had stored on the MicroSD card in the KANN MAX. The rollicking track Enrique El Cobrador from the album Smote Reverser (best cover art ever, by the way) proceeded to shake my earholes with dynamic, driving bass as the KANN MAX powered the party on with a terrific sense of drive, power and grip on the little 18-driver 64 Audio IEMs. Drums are the first thing to tell you when things sound a little “off”, but the excellent drum recording in Jettisoned from their 2017 album Orc sounded bloody brilliant with the KANN MAX and 18s teamed-up. You could almost “see” where each drum/cymbal mic was placed around the kit, and each hit of the skins and cymbals peppered away with a nice crisp attack, and decayed no longer than they ought to. 

Next up was the Grado SR325x Prestige Series Headphones - not a particularly difficult load for an amp at 32-ohms/99.8dB, but I decided to re-terminate my pair with a 2.5mm balanced connection for situations just like this one: getting the most out of a portable player’s power. Grados absolutely shine with metal, so I wanted to see if the little KANN MAX could get them “rock out” with Pantera’s 1992 album Vulgar Display of Power, which is about as rock-y as albums get. “Medium” amp mode proved to be more than ample with the SR325x, and I had the volume around the 50/150 mark. Vinnie Paul’s signature double kick-pedals sounded utterly brutal, pounding away with awesome speed and impact while his brother Dimebag’s solo wailed away overhead. The KANN MAX is an energetic-sounding DAP, and certainly benefits from having the voltage and headroom to offer plenty of dynamic swings when the music requires it. 

It was time to turn up the KANN MAX’s amp to “high gain” with the 300-ohm/102dB Sennheiser HD800s Audiophile Headphones, which also required more than a few spins of the volume wheel up to 70/150 to get Under Cover Of Darkness, a killer song off an “ok” album from The Strokes up to party levels on the HD800s. This track has a very simple, but damn enjoyable bass line that’s double-tracked with one of the (many) guitar parts, and it absolutely slams when the 12Vrms on tap in “high gain” are fed into the HD800s via a 4.4mm balanced cable. Does the KANN MAX have the juice to power the HD800s properly? It sure does. Does it sound good too? You betcha. Not once did I feel like the KANN MAX was about to run out of puff or headroom with the HD800s - as well as a solid foundation of dense low-end, the KAN MAXX eked out every last scrap of air, detail and sizzle from those 300-ohm drivers.

The final test for the KANN MAX was perhaps a little unfair, as I didn’t have an appropriate adapter on-hand to connect the 60-ohm/83dB HIFIMAN Susvara Planar Magnetic Driver Headphones into a balanced connection, and so had to settle for connecting it into the 3.5mm output with “only” 8Vrms of power available. I wasn’t holding my breathe when I pressed play on The War on Drug’s Under the Pressure, but with the volume wheel stopped at at 105/150 I found that I didn’t want to go any louder - not because I was worried about my hearing (well, that too), but because it simply sounded good. Everything was as it should be with the mighty Susvara - the bass was plentiful, there was plenty of air and space around the soaring synths, and the baritone sax part hit with a delectably fun texture. Ok, so it did sound a little “flatter” than on a high-powered desktop amp in that it sounded less spacious and didn’t quite have the same dynamic impact, but the fact that there was still plenty of room left of the KANN MAX’s volume wheel was pretty impressive - now I just need to get my hands on a 4.4mm cable for the Susvara so I can go back for round 2!

Update: my curiosity got the better of me, so I pulled out my soldering kit and got to work affixing some 2.5mm terminations to the earcup ends of a balanced headphone cable. After my multimeter told me that I'd wired the four wire strands correctly, I plugged the Susvara into the KANN MAX and fired up one of the most difficult and telling tracks in terms of bass slam and extension, Aphex Twin's produk 29 [101] from his classic Syro album. The little DAP needed noticeably less power to reach the same sound pressure level - around 94/150. The Susvara sounded pretty damn convincing playing through the balanced output of the KANN MAX - the deep electronic sub bass notes hit with authority, and no hint whatsoever of flab nor the slight sense of "anaemia" that I got from the single-ended output. The Susvara's sense of excellent imaging and head-stage felt fully present, and the highest octave had plenty of air as well as decent tone and extension. In short, if you're the kind of person to take a Susvara away with you on vacation, the KANN MAX should definitely be in your carry-on luggage. 

Final thoughts

Compared to other compact DAPs, the KANN MAX is a streamlined, well-built, good-looking device that’s easy to live with when it comes to playing music both offline and online thanks to its terrific DAC(s) and wifi and streaming talents. And if you were to leave it there, it would seem like a pretty compelling device as in. 

However, it’s almost unbelievable to wrap your head around the fact that a device this compact can pack this much of a punch. To quote Han Solo, “she’s got it where it counts kid” - the KANN MAX is an astonishingly powerful DAP that’ll also play nicely with IEMs (if you ask it to). If you’ve been on the fence about taking your planar magnetic headphones with you on holidays because you won’t have anything to play them on properly, then you’d better reconsider things. It almost seems unbelievable given its size, but the proof is definitely in the pudding (and by “pudding”, I mean listening). And for that reason you’d better put the new KANN MAX on your “Things to Audition” list next time you drop into your nearest Addicted To Audio store.
Astell&kernDaps (digital audio players)