A New StandardA new standard for listening to music was proposed while developing the AK100....

Astell&Kern AK100II High Resolution Single DAC Audio Player

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  • A New StandardA new standard for listening to music was proposed while developing the AK100. Astell & Kern recognized that certain aspects of the AK100 needed improvement during research and development for a successor. While considering how to improve the AK100, they realized that there was a difference between measured audio specifications and what they felt sounded good. After much deliberation, their development efforts were focused on making the AK100 2nd Generation "feel" right to their senses rather than mechanically boosting technical specs. The original AK100 was developed according to audio specification standards, but development of the next-generation AK100 was developed to the "New Standard" of how the music sounds. Astell & Kern presents "A New Standard in Listening to Music" with the AK100 2nd Generation.Single DAC and Balanced OutAlthough the dramatic depth in sound quality delivered by the Balanced Out was proven in their flagship model, Astell & Kern wondered if the same benefit could be gained by implementing the Balanced Out with a Single DAC. The newly designed demo board delivered the ear-pleasing sound quality that is needed. The value of a Balanced Out with a Single DAC is confirmed with every musical note. The AK100 2nd Generation provides a rich, warm sound experience through the re-tuned A-amp designed specifically for the CS4398 Single DAC.Unbalanced vs. Balanced OutputThe unbalanced method is the most commonly used basic method which

Recent User Reviews

  1. JoeDoe
    "Astell & Kern 100ii: The Gatekeeper"
    Pros - Aesthetics, Sound quality, Design, Additional features
    Cons - MSRP, File transfer for Macs
    The AK100ii is a DAP I've had my eye on for quite some time. At first glance, it's obvious that it's a premium piece of kit, with it's clean efficient lines, quality touch screen, minimal physical interruptions, and compact size. Reading up on it's specs and the fact that it keeps (and improves) on it's previous iteration leads one to believe that for the asking price, this should be a one stop product, where a bunch of tweaking, additional cables, outboard DACs or amps shouldn't be necessary.
    And ya know what? It lives up to the hype.
    The Hits 
    1. Support for every lossless format under the Sun
    2. USB DAC capability
    3. Wi-fi and Bluetooth capabilities
    4. Smoothest, most natural UI I've encountered
    The Misses
    1. Physical button layout
    My Thoughts
    To give you an idea of where I'm coming from, my head-fi DAP history has included a plethora of iPods, a sample of Sansas, a cache of Colorflies, a basket of iBassos, and a few Fiios. Some like the iPods, C3, and DX50 were used with additional amps & DACs, while the X3, X5, and DX90, have been standalones. 
    For a while, the X5 was my go to as it checked off just about everything on my list. After all, most of my music is redbook quality, my main headphones are very easy to drive and I have no desire to have to carry a giant stack of gear around. Portable audio should be portable after all! 
    The X5 never left me feeling like I was missing much on the sound end of things, but when a nice deal on a secondhand AK100ii came up, I pulled the trigger. Figured if for whatever reason, I didn't like it, I'd be able to move it along quickly. After giving it the full run-through with my RS1, GH1, and 1+2 however, there's no doubt in my mind that the X5 has been usurped.
    Starting from the bottom, the bass is truly and completely audiophile quality. There's no bloat, no over-the-top sub-bass, and no Earth-shattering mid-bass lift (unless they're already in the recording). What I'm hearing is bass that is incredibly textured, articulate, fast, and dynamic. When called for, it can certainly bring the rumble, but that's only when I'm listening to hip hop or EDM which have that sound in the recording. The AK has made me realize that the X5's low end was a little warmer than I realized, perhaps to strike a happy medium between the budding audiophile and average consumer. 
    In a word, the midrange is... neutral. I'm definitely a mid-centric listener. My entire desktop rig is designed around the RS1's incredible midrange. And while I loved the thick and lush vocals and crunchy guitars that the X5 gave me, going to the AK has shown me that I was losing out quite a bit on texture and depth. The 100ii doesn't just rush voices to the front of the mix. They stay a little further back so they sound more cohesive with the rest of the track, rather than isolated  to give them the spotlight. I'll admit sometimes I miss the warmth that the X5 lent to Norah Jones and John Mayer, but I think what I've gained in my upgrade is easing my suffering [​IMG]
    Treble. Clean, airy, textured, and sometimes, a touch too clean. If there's one sonic characteristic about the AK that gave me pause when I first received it, it was the upper end. It's incredibly uncolored and detailed. A clear step up from the X5 and the DX90. However, every once in a while the Grados and the Tralucent would get a little abrasive on abundant cymbal crashes or peaky female vocals. I added just a bit of EQ and rolled some foam tips onto my IEM's and now we're good to go. Now bear in mind, I'm a little treble sensitive, so fear not, I'm not saying that this headphone is nails-on-a-chalkboard screechy at all. It's overall presentation is very clean and neutral. It's gonna give you what's on the recording. If you've got treble-happy headphones, they're not going to be tamed. And if you've got warmer cans, the extra clarity on the upper end may be a nice synergy for you! YMMV.
    With regards to soundstage/separation/depth/etc. the AK is the best I've heard in a portable solution. This is where I feel like DAP's really separate themselves and the AK shows that it's clearly a force to be reckoned with. Because of that ultra-clean treble, instrument separation is excellent; leaps and bounds ahead of anything I've heard from Fiio or iBasso. Soundstage width is only a little above average, but depth is quite good! The 100ii really shows off how capable the 1+2 is in this regard. 
    I don't care to spend too much time in this section because frankly I don't need to. I read a post recently about how a company choosing to employ the computer power of something of this caliber should make the UI almost cell-phone like and I agree... partially. If you're trying to market a premium product, IMHO premium sound is only half the battle. A premium UI is the other half. Luckily, the Android-based UI that AK has developed is very straightforward and easy to use. Granted there have been several firmware updates and as far as I know, they are still continuing to improve, but mine is running 1.25 and I don't feel like anything is missing. Menus are intuitive, controls are easy, there is minimal lag, and I've yet to experience a freeze or crash. When I rolled with the X5 and the DX90, I could navigate well enough, but I definitely felt like the UI was an afterthought. 
    The only real qualm I have with this player is the file transfer protocol for Mac users. You have to download an app called Android File Transfer and quite frankly, it sucks. It's inconsistent. It's slow. It often hangs up. And it's incredibly limited in it's capabilities. Makes a new DAP owner a little bummed that he's got to try half a dozen times just to get his music on his player! Would love to see this little feature fixed either on AK or Android's end. 
    I should also mention that the 'extra' features that AK chose to include are well-done EDIT: ok and appreciated. These include wi-fi capability for streaming, Bluetooth for wireless play, and USB DAC functionality that works very smoothly. The only one I really wanted was the USB DAC, but now that I have the others, I'm certainly feeling like I got more of my money's worth.
    EDIT: Went back to further confirm these and didn't have a lot of success. They worked, but were a little inconsistent. Luckily for me, I don't use either of those functions very often.
    In summary, the AK100ii, a.k.a. The Gatekeeper (for the land of portable high resolution listening) is a very well-made and designed product that anyone (that's ready to pony up for it's asking price) should consider. Now that it's been out for a while, firmware is very solid, and finding one on the used market makes it even more affordable. 
    If you want neutral, clean sound with a slew of extra capabilities, then the Astell & Kern 100ii should be on your short list of players!
    LikeABell likes this.
  2. cvbcbcmv
    "Lots of Sound in a Small Package"
    Pros - Clarity, UI, Design
    Cons - Poor wifi strength, Boot time
    After countless hours of enjoyment, I believe it's finally time for me to publish my review of the Astell and Kern AK100ii. 
    Design/Build Quality:
    You don't need to own an Astell and Kern product in order to see the effort they put into the craftsmanship of their products. The blend of aluminum and glass bears resemblance to an Apple Product, and an untrained eye might even guess one of their players is the result of Apple's design team. Among the audio community, however, Astell and Kern stands out as creating some of the most beautiful and easily recognizable products of any company. The AK100ii is no exception. 
    Press renders can make any product look beautiful, but it's how the product looks in-hand that truly matters. The AK100ii does not disappoint. In fact, when I first took it out of the box, I couldn't believe just how wonderful it looked and felt in person. The metal build did not lead to a heavy device; instead, it felt like the perfect balance of solid build and portability. I was used to using DAPs made mostly out of plastic, and while their designs were all fine, a metal build just adds a new level of luxury. Everything feels sturdy and well machined. My device has even taken a few drops at the gym, but it has held up just fine. The buttons have a nice click and are easy to press. My favorite part of the design, though, has to be the volume wheel. It looks fantastic, and it scrolls with the perfect amount of resistance. The screen is as good as most high-resolution smartphones we have become accustomed to, but it doesn't need to be, and it does just fine making album art look crisp and clean. In summary, the AK100ii has a build that feels solid, tough, and luxurious. 
    The AK100ii connects with a standard Micro USB cable on the bottom, and you can use either the standard 3.5mm port, or the 2.5mm balanced one that AK is known for using. Additionally, it comes with 64gb of internal storage, with 1 microSD slot for expansion. 
    User Interface:
    Like most of AK's other devices, the AK100ii runs a highly modified version of Android. When I first got the device, I resented the fact that I felt like AK was missing out on including a killer feature: Streaming with apps like Tidal. I mean, all of the pieces and parts seemed there. A high end player with Wifi running Android, why wouldn't they include it? However, after my initial troubles with the Fiio X7, I think AK decided to skip out on the music streaming in order to preserve a product that simply worked well. They accomplished just that, so I respect their decision to not try and rush streaming. 
    Overall, I find the interface on the AK100ii to be very intuitive and streamlined. The home screen shows any currently playing music, album art, and a set of options into how you would like to browse your music (artist, genre, etc.). The "store" feature is a relatively new feature that I cannot comment on since it is not active in the United States. 
    Everything about the AK100ii just works. It takes some time to get used to all of the controls, but it's an intuitive device, and it's very reliable. Just as I think AK bears resemblance to Apple in physical design, I think they are similar in their UI design as well. The AK100ii does not try to do much, and as a result, everything it ​does do, it does very well. For example, having wifi built in leads to endless possibilities of features, but AK has decided to limit it to OTA updates, which works very well (Note that I am not including the store feature as I cannot test it). I do not mind trying and learning new technology, but for the less tech-savvy person who may be intimidated by the modern UI of the AK100ii, I think with a little bit of time and patience, anyone should have no trouble learning it.
    There are a few cool little tricks with the UI here and there. For example, being able to physically draw a curve in the EQ is a nice touch. 
    It's very easy to move between songs, and the device is very quick. I never experience any kind of lag, and when I click on a song, I don't have to wait for the processor to catch up before I get to listen to music. The AK100ii only has one real negative when it comes to the UI, and that's the boot time. I just timed it, and it took my device 43 seconds to fully boot up. Believe me, this waiting gets very old very fast. 
    Transferring music from the computer to the AK100ii is generally quick and easy. I only specifically note it because if you use a mac, you have to use Android File Transfer. It is extremely easy to setup, though, and in my opinion is not a big enough issue to be a negative. 
    ​Battery Life:
    Battery life for this device, especially compared to other Android, touch-screen based devices, is pretty good! I mostly use it at the gym, and I can get through a full 5 days of workouts that average about 2 hours each before I need to recharge. Recharging could be a bit quicker, though. Granted, I was using a computer, but sometimes when the device is near dead and I plug it in before I go to bed, the next morning it's only around 3/4 charged. What I really think is the judge of battery life in real life, though, is does it last long enough to be able to get through any reasonable situation before having an opportunity to recharge? For example, a long flight, a long drive, etc. In my experience, the answer has always been an easy yes. 
    Well, this device certainly isn't cheap. With an MSRP of $899, you better not just be paying for luxury and design, as I sometimes see AK being criticized for. While I can't comment on all of AK's products, as far as the AK100ii goes, I think the price is very fair for what you get.
    I will reiterate what I frequently hear said about AK's sound: It is clear. Clarity was the word that came to mind when I first listened to the AK100ii, and it remains that way today. All aspects of the sound are extremely clear and transparent, and the soundstage is very wide. Especially when paired with a headphone with a wide soundstage, the AK100ii creates a sound that is very easy to get lost in. 
    Furthermore, I find the AK100ii very neutral and balanced. On other–granted less expensive–players I have listened to, I find that sometimes the upper-mids and highs can get hidden over a somewhat uncontrolled low end, and upper-highs can lose their shimmer, but the AK100ii has a good, punchy low end, but with no lack of detail in neither the mids nor the highs. Everything always stays tight, controlled, and clear. Nothing gets buried or hidden, and all aspects of the sound are given respect. I feel as though the AK100ii is tuned in one of those perfect ways so that no matter what kind of sound signature you like, the AK100ii suits it. If you're a bass head, it has enough bass to please you. If you like detailed shimmery highs, there's plenty there. If you love detail in the mids–you won't be disappointed. It's not too hot, it's not too cold–it's just right. 
    As far as driving more power-hungry headphones, I would personally never expect or intend on using solely this device to drive any full-size headphone that is a bit power hungry, but I was pleasantly surprised with how it handled my LCD-3's. The AK100ii cannot drive them optimally, but it can certainly drive them to a listenable level. I wouldn't recommend the AK100ii for anything beyond IEM's and more efficient headphones, but in a pinch, it works. I frequently use the line out function–which simply sets volume to max–and connect the AK100ii to my Schiit Mjolnir to drive my LCD-3's, and I love that setup. 
    So, is the AK100ii worth it? In my opinion, yes. Not only do you get a product with fantastic, durable, and luxurious design, but you get a product that sounds awesome, and likely will suit anyone's ears. The AK100ii has a sound that's very easy to love, and very hard to hate, no matter what kind of signature you like. Before purchasing the AK100ii, I was mostly using the Fiio X3ii, and I had listened to the Fiio X5ii for long enough to get a feel for its sound. In my opinion, the AK100ii is a sufficient step up from those products for the additional cost. Regardless, I think the AK100ii is a safe buy, if you are willing to spend the money.
    WayneWoondirts likes this.
  3. WayneWoondirts
    "AK100II - addictive high end DAP"
    Pros - Sound, UI, Features, Build, Screen
    Cons - firmware 1.25 messed up a lot, mSD slot hard to reach

    I was provided with a free sample of Astell & Kern's DAP for this review by a local distributor.


    Because of a small series of lucky coincidences I found myself on the phone with the CEO of AudioTuning, Austria's biggest audio distributor, and after a few minutes I got offered to review the AK100 II, which couldn't be declined. How often do you have the opportunity to test one of the best DAPs?
    A week later my review package arrived, right after I finished my time with FiiO's second gen. X5, and at the moment this was the best sound I've heard. This was about to change very soon.
    The box delivered what I knew about A&K. Elegance, style and absolute high end quality.
    The AK100 II is the very first touch device I've used for more than just a few minutes, and it is the first I felt comfortable using, more on that in the UI section.
    Its heart is Cirrus Logic's CS4398, the same as in the AK120 II and AK240. But the AK100 II only uses a single DAC chip. The battery has a capacity of 3150mAh, which gives the device power for about eight to ten hours. It features WiFi and bluetooth streaming.
    The AK100 II has 64GB of NAND storage, which can be accessed via MTP from every Windows, Mac or Linux computer. Only about 56GB can be used for storage though.
    Firmware upgrades are available through WiFi/OTA (OverTheAir). My device was running firmware version 1.12, later on the upgrade to 1.25 was released.
    Headphones used:
    Final – Sonorus VI
    Final – Heaven VII
    Pro-Ject – Hear it One
    other gear used:
    Cambridge Audio – Go V2
    Pro-Ject – Stereo Box S + Speaker Box 5
    Self built laptop running OpenSUSE 13.1
    Package and Accessories:
    The box comes in a matte black cover, which already screams premium from every corner. After the cover is slid off, the main box comes out. Again, everything from Astell & Kern is designed to remind you that you don't have an everyday DAP in your hands, this is how high-end feels like. And on every removable content, even on the mSD slot covers, there's the logo of A&K so you don't forget who brought you this experience.

    The opened box brings out the AK100 II. Here it is. It's lying there peaceful and waiting to be discovered.
    Under it is the box with all the accessories. What you get is a gray leather case for the DAP, a protective film, a mSD card slot cover (one's already inside the slot), a micro USB cable for charging and data transfer, a warranty card and a quick start guide. The screen has a protective film pre-applied.
    Content summery:
    AK100 II
    Gray protective case
    micro USB cable
    two mSD slot covers
    protective film for the back
    Warranty card
    Quick Start guide
    The AK100 II is completely made of aluminum, only the back is covered in clear plastic. You will definitely feel its weight of 170 grams in your hand.
    The front face of the device is nearly completely used for the 3,3 inch AMOLED touchscreen. Which is readable without any problems, the screen brightness can be easily adjusted with a swipe down from the top. The player feels great in hand and its size is perfect for one hand navigation. I can reach every corner of the screen with my thumb and my index finger takes over the volume control.
    On the left side of the AK's body are the three hardwarebuttons for play/pause, previous and next track. Also the mSD slot is found there.

    On top there are two jacks. A regular mini jack for phone/optical out and a 2,5mm balanced out. Next to the balanced out jack there's the powerbutton. The only thing on the right side of the device is the volume control wheel, where you can set the volume in 150 steps.
    On the bottom there's only the micro USB port for charging, data transfer and USB DAC function.
    One thing that could use some work is the mSD port, it is really hard to insert and extract the card, since it's pretty deep in the device. I almost always used a second mSD card to get it in/out.
    iriver really pulled the design. It is the best looking DAP I've seen so far. It's not bulky or unhandy, yet beautiful and unusual stylish and at some point I felt under dressed.
    User Interface (UI):
    The UI is based on Android, and definitely the best one on the market. Only Rockbox beats the AK's interface. It is designed to be very easy and intuitive. Every content is reachable with your thumb, which makes navigating very simple.
    The AK100 II will let you search your songs by title, artist, album, genre or playlist. You can also search your database with the songtitle directly or sort your songs by quality (All, MQS, DSD). Or you can easily access your songs by folder view.
    It features a wonderful playlistmanagement, where you can simply add artists, albums or single songs to the current playing songs. Or you can drop them into an existing playlist or create a new one.
    The home button brings you back to the main screen with a short press.
    With a swipe up or down over the cover art you can either play the next or previous song.
    If you go through your library and swipe down the screen the UI will show a scrolling bar on the right side of the screen for you to go even faster. A wonderful feature for huge playlists and databases.
    A swipe down from the top brings you all the quick settings you need. You can easily access the most important settings. Turn on/off wifi and bluetooth. Change from MTP connection to USB DAC function. Activate the equalizer, gapless, balanced and line out. Set the play mode and brightness. It also shows you the most recent and important notifications. In the upper right corner you can access the settingsmenu. If you long press WiFi, bluetooth or EQ you can move to the corresponding screen.
    One thing that caught my eye was the equalizer. It's a ten band EQ, which features two presets, Pro (settings as recommended by professionals) and AKT5P (for the headphone with the same name, made by beyerdynamic), these can not be modified. But you can also add custom EQ curves by adjusting the frequencies of the 10 band EQ. I hardly use it, but when I do I create customs for my headphones instead of genres. That way I can fine tune my cans to the desired sound.
    The top part of the screen is the notification bar, which shows you what's currently enabled, e.g. shuffle, Line Out, WiFi, bluetooth, battery percentage, time etc.
    The only things missing in the firmware are replaygain and putting songs in queue, there is a feature, only sensible imo when playorder is not set to shuffle, to move songs around in the playlist.
    Also there's only one bug in the software, the device never remembers the USB mode settings. I always had to set it back to DAC. Luckily the UI was well designed and the quick settings are accessed extremely easy.
    P7300328.jpg P8210401.jpg
                     UI with firmware 1.12                                                              UI with firmware 1.25
    P8210402.jpg P8210405.jpg
       Quicksettingsmenu open with a swipe down from the top                          Now playing screen
    Changes of the new firmware (1.25, released August 18th) which should get reverted in my opinion:
    - long pressing the home button brought you back to now playing before, disabled now.
    - the ability to draw EQ curves for a fast and easy way to add custom settings
    - home screen now takes up way too much space, the buttons were already very well designed in the previous firmwares.
    - for faster scrolling the bar on the right side (in database) used to be an alphabet, to get you to a specific letter.
    - USB DAC makes audio out of sync, very annoying!
    Bluetooth streaming:
    The AK100 II also supports bluetooth streaming to portable speakers or wireless headphones. It comes with bluetooth V 4.0 and no aptX support.
    The bluetooth streaming option is recommended for any file format up to 48kHz, any higher resolution files may stutter. And I tested that too, it did.
    I tried streaming different high-res (96-192 kHz) files to my Cambridge Audio GO V2 and all of them had hiccups. Everything below 48kHz was fine.
    It will be a long way until bluetooth streaming will get close to the quality a wired connection offers in my opinion.
    USB DAC:
    At first I was a little worried that it won't work as USB DAC since I've read that a few Mac users had problems connecting the device with their computers. But all worries have stepped aside as soon as I tried it out myself.
    I only use Linux machines, and never have I had any problems using the AK with either my laptop or my PC. Everything works out of the box (with pulseaudio en- and disabled).
    Unfortunately the highest supported format is 24/96, so everything above that will get downsampled.
    The new firmware also changed the DAC function, and not in a good way. When using the AK100 II as DAC and watching movies you'll definitely notice that it is out of sync! The audio is about half a second late, and this is not what you expect from a 1200€ device. VERY DISAPPOINTING!
    @Limexx found a fix for Windows machines:
    1. Right-click the speaker icon and click 'Playback devices'
    2. Double-click the AK100ii
    3. Go to advanced
    4. Unclick exclusive mode
    So far I couldn't find a global solution to this problem for Linux/Mac users.
    If you're using VLC you can easily fix the synchronization by pressing J or K while the video is played, but the delay's still present with any other content (e.g. youtube videos)
    iriver does not want their players to be in the same boat with the others, that's why they call their DAPs “Mastering Quality Sound Portable Systems”, and that's what they are.
    I have heard FiiO's new generation X5 because I also wrote a review for it. I was, and am, really impressed with the sound that comes out of it, but the AK is a whole different league. It makes the FiiO sound muffled and very analytical.
    The AK100 II has a huge and super realistic soundstage with the best image I've experienced. It's unbelievably balanced and neutral. In fact it's the most neutral sound I've heard coming out of any device, desktop or portable. It has a great vivid body and a lot of air between the instruments. Its attack, decay, sustain and release are very impressive. It also has a very black background. Every frequency gets delivered fast, crisp and super precise with outstanding instrumental separation. This is how it's supposed to sound like, true mastering quality.
    The firmware upgrade was very noticeable in sound. It made the device sound even cleaner, wider, more natural and precise.
    The AK100 II makes any other DAP I've heard sound boring and blurry, and I don't know how to go back to the X5 now.
    I tested the AK with three different headphones. Pro-Ject's Hear it One, and Final's Sonorus VI and Heaven VII.
    The Hear it One has a wonderful soundstage for a closed back headphone, it sounded great, a little warm but over all very well defined. Highs are very sharp while mids come along very smooth, bass is overly present for my taste. Listening to Jazz recordings, especially Dave Brubeck's Time Out in DSD quality, with this headphone was the best combination for it. Trumpets, Snares and Basslines sound very natural and smooth.
    The Heaven VII shows more detail and better soundstage, also more neutral and natural. The highs are this headphone's strongest point. You can almost feel the strings and triangles. Also the bass lines appear clearer and more lifelike.
    The Sonorus VI are definitely the best headphones in this comparison. The soundstage grew again from the previous phones. Overall the sound is more vivid, precise, neutral, detailed and natural. This is the best setup in my home for the AK100 II. It also was my main combination in the time I had the AK. The sound showed astounding microdetail and instrument separation I can not compare it to anything I have heard so far.
    I think to enjoy the AK's full potential you should listen to it with proper headphones, even though it brings out the most of the lower end cans, you will experience something amazing with better iems/headphones.
    The AK100 II is the whole package. You get incredibly beautiful design, the best user interface and addictive sound. But you have to pay a lot of money for that, if it's worth it is yours to decide.
    The lag in DAC mode's a huge disappointment, I really hope Astell & Kern/iriver will fix this with the upcoming firmware, it worked perfect with the previous release.
    Currently you can get it for $899 or €1199.
    Final Words:
    Again I would like to thank AudioTuning for providing me with a sample of the AK100 II for this review. It was an unbelievable experience.
    With a heavy heart I have to send it back now.

    If you have the chance to audition an Astell & Kern, do it, but remember, their sound might not let go of you.
    dnun8086, Light - Man and ezekiel77 like this.

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