Astell&Kern AK100 Hi-Res Mobile Player SRP: $699

by | Dec 10, 2013 | Component Reviews

Display: 2.4″ IPS touchscreen
Audio formats: WAV, AIFF, FLAC, ALAC, APE, MP3, AAC, WMA, OG
Maximum sample rate: 192/24
Continuous playback time: Up to 16 hours
Memory capacity: 32GB (+ up to 2 x 32GB microSD)
Supported OS: Windows XP and up; MAC OS X 10.6.5 and up
Size: 2.33″ x 3.11″ x 0.57″
Weight: 4.3 oz.

iRiver Inc.
39 Peters Canyon Rd.
Irvine, CA 92606



Since its founding in 1999 iriver has become renowned for its award-winning product innovation and record of market leadership. Its products have included multimedia devices, network devices and content devices such as the E-Dictionary and E-Book. They have introduced two different hi-res mobile players: the AK100 reviewed here, and the AK120, at $1,299. The latter has advantages in specs, functions and componentry, but sounds only very slightly better. The AK120 uses two Wolfson DACS, has lower jitter, and can hold up to 192GB of music, while the AK100 can only hold up to 96GB. The two digital storage mini-cards each store up to 32GB of memory in the AK100. The AK120 also supports DSD, which the AK100 doesn’t. Both devices have high quality brushed aluminum finishes and an up-to-date sort of feel to them.

Good quality headphones are an important part of the equation for auditioning the AK100. I used my Grado SR-80s, which sounded terrific. I had always thought that there was little use for hi-res recordings on a mobile device, due to all the noisy surroundings that one was usually in, whether you had good headphones or not. I was wrong; there is a definite value in hearing pretty much the same high degree of fidelity you get with hi-res audio files on your home system, but listening portably with an AK100 and good headphones. The AK120 has more options for headphones, but I found the Grados a fine match to the AK100. The nice thing here is that no reference system is required to hear the fantastic fidelity of hi-res recordings stored on the AK100.

The device came with a variety of already-installed hi-res audio files, as well as some standard 44.1K/16-bit files (which surprised me since I thought the whole idea was to promote mobile hi-res). The 96K/24-bit files sounded amazing, and at my age I don’t hear any enhancement with 192K/24-bit audio files. I was very disappointed to find that an Elgar cello album I had downloaded from HiResAudio in Germany was just 48K/16-bit and didn’t sound much better than standard CD-quality files. There was a rather odd variety of hi-res samples on the AK100, including Rebecca Pidgeon, Willie Nelson, Ray Charles, Eric Clapton, Stan Getz & Joao Gilberto, John Coltrane, and cellist Janos Starker in several selections taken from the Bach Solo Cello Suites. I especially enjoyed the Bach cello excerpts from the Mercury Living Presence set, which sounded just as excellent and realistic as the Mercury three-channel SACDs do on my home multichannel system.


I admit I’m not a user of any mobile digital devices, so getting used to the AK100 took me some time. I found it extremely frustrating to use. It automatically repeats every track, and the manual advance button on its side often doesn’t work.  The touch screen also didn’t work about half the time with me, though I tried both light and heavy touches. I only was able to locate the Elgar cello selections I downloaded to the AK100 one time, and after that they disappeared. The earlier units were not gapless, and would insert a second or so pause in the midst of classical works that were intended to go on from section to section without pause, but this was corrected in a recent update. It takes some time to become operational after you first turn it on, and can be difficult to turn off – always using the tiny button in the right top of the unit.

I also found the touch screen rather small and difficult to move within, and noticed that frequently even gingerly putting the AK100 back in one’s pocket caused a huge reduction of the volume, which then had to be adjusted back up again either on the touch screen or with the small volume knob on the right side. The only indication of battery life is a very tiny battery icon in the upper right corner of the screen, and it takes several hours to completely charge by hooking into the USB port of your computer.  Astell & Kern call the hi-res files MQS, which is a bit confusing since nobody else uses that designation. There is also the danger of dropping the delicate device and, poof! there goes $700!

I am aware the high-end audio publications, both print and online, have gone nuts over both Astell & Kern devices, but personally I feel they are both overpriced for what you get. Sony has a new digital Walkman only available to far in Japan and the UK, but although it was announced at about $150 when it would be released later in the U.S., it now appears it will be close to $900.  However, it has much larger storage and a larger screen. One of the reviews also mentioned the earlier Apple iPod Classic, which used superior Wolfson DACs, and although it won’t accept hi-res files sounds much better with standard audio files and is only about $100 used on Amazon.

—John Sunier


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