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Astell & Kern AK240 review

Astell & Kern AK240 front angle screen
Astell & Kern AK240
MSRP $2,500.00
“If you’re part of the crowd for whom money is no object, and you want to experience your entire music catalog as though you’d never heard it before, the AK240 might just be your new drug of choice.”
  • Unparalleled mobile audio quality
  • Plays virtually any file type
  • Perfected, feature-packed interface
  • Makes every song in your catalog sound better
  • Premium aesthetic
  • No online browsing option
  • Can’t yet upload songs directly from browser
  • Mediocre battery life
  • Expensive, expensive, expensive

High resolution portable music players have been thrust into the spotlight recently, thanks to the unveiling of Neil Young’s long-planned PonoPlayer and music-downloading ecosystem, PonoMusic. Garnering $1.5 million in only its first day of crowd funding on Kickstarter, the PonoPlayer, which will retail at $400 upon release, has shown there may be broad demand for a device that trades quantity for quality when it comes to music on the go.

If the PonoPlayer is the everyman’s high-definition portable music rig, the choice for the affluent would have to be the Astell & Kern AK240 Dual DAC, from iriver. Trailing a shocking $2,500 price tag, the AK240 is truly a regal machine. For that massive mound of dough, users get access to some awesome features, including an AMOLED touchscreen, support for virtually any digital audio file up to 24-bit 192kHz resolution, digital streaming of your music catalog over Wi-Fi, and a heap of other features and high-end components.

In this review, we’ll dig deep into the AK240 to see what a king’s ransom can secure in today’s blossoming world of high definition audio, and whether the device mounts a valiant enough effort to defend its breathtaking asking price.

Video review

Out of the box

There’s no question that unboxing the AK240 is a premium experience. We’re not sure if it’s an experience worthy of a device priced on par with a used car, but it’s a sleek setup. Pulling away the box’s outer shell unveiled a thick box of textured black cardboard beneath. Removing the cover revealed the AK240 sunken into a sumptuous layer of velvet padding, its gun-metal frame gleaming ever so slightly in the light. The device felt satisfyingly heavy as we removed it from its perch, and the sharp-angled profile cut an aesthetic somewhere between an 80’s V-guitar and a Lamborghini Veneno.

Spinning the device around revealed a gorgeous backside, its carbon-body face sparkling brilliantly beneath a translucent cover. The most distinguishable characteristic along the player’s case was a solid dial at the upper right that spins with a satisfying click to change volume at precise increments. The dial is matched on the opposing side by three physical control buttons for song search and play/pause.

Under the top layer of foam inside the box we found two small cartons of accessories, including a USB to mini-USB cable for charging, a spare SD card, a packet of instructions on heavy black construction paper, and a solidly-stitched leather case.

Features and design

The AK240’s aesthetic experience is one that unfolds over time, slowly revealing its premium traits as you delve more deeply. The carbon face along the back, the OLED touch screen, and the elegant-yet-macho ‘duralumin’ shell all divulge a plush aesthetic. Yet, from afar, this piece can look a little bit odd, almost as if Microsoft’s much-maligned Zune brand crafted a high-end smartphone.

There are a bevy of features to explore with the device, including multiple ways to play that allow it to act as the sound source for your entire home theater system. The ports at the top include a 2.5mm balanced stereo output, and a standard 3.5mm headphone output that also doubles as a SPDIF digital optical port. In addition, the player can be used as a USB DAC for a Mac or PC, and can also stream files wirelessly.

Virtually all of the hardware controls along the body are doubled by touch commands via the AMOLED (active matrix organic light emitting diode) display, but the volume dial stands alone. Spinning the tactile knob displays volume increments with a ripple of digital lines on the screen that expand at half-point intervals from 0-75.

The sharp-angled profile cut an aesthetic somewhere between an 80’s V-guitar and a Lamborghini Veneno.

Touch control for the rest of the features is fairly self-evident for anyone who’s picked up a digital music player, with apparent categories like Album and Artist, and a deeper layer of options revealed by a drop down window that appears with a sweep of the finger from the top of the screen. Controls in the dropdown include touch icons to turn on basic options like Bluetooth, display brightness, and shuffle, as well as deeper features such as EQ and Wi-Fi. Holding many of the icons engages deeper options, such as the 10-band graphic EQ window which can be preset or tailored to your taste, and Wi-Fi setup options for local networks.

Another layer of options can be accessed via the Setting window, which pulls up some added features such as line out or balanced outputs, adjusting stereo balance, or checking for firmware updates.

Unfortunately, the AK240’s Wi-Fi connectivity doesn’t allow for any web browsing or even downloading of tracks directly to the device, though the latter is reportedly on the way. Instead, the feature is designed to allow users to stream digital files via the device’s MQS Server feature, which sends files over a LAN at the full 24 bit 192kHz resolution. An application must be downloaded to your PC or Mac to enable the feature, with support for Windows 7, or Mac OS X Lion 10.7 or above.

The player supports a serious variety of files and resolution levels, including (deep breath): FLAC, WAV (8-192 kHz, 8/16/24 bit), WMA (8-320 kbps), MP3 (8-320 kbps), OGG, APE (Normal, Fast, High), AAC, AIFF, ALAC, DFF, and DSF. It will also play double rate DSD formats at a max 298 Mhz. A new firmware upgrade that recently dropped will also allow for support of DXD files from 8-320 kbps as well.

Astell & Kern AK240 volume controlOf course, all of that means nothing if the music files you’re listening to aren’t transferred into analog audio by supreme digital-to-analog conversion hardware. To accomplish that task, the AK240 employs a two-pack of Cirrus Logic 4398 DACs (one for each channel). The folks at iriver reluctantly dropped the lauded Wolfson 8740 for the AK240 simply because the Cirrus Logic chipset allows for native transferring of DSD files, without first converting it to the PCM (pulse code modulation) format. In theory, that should translate to a much more accurate transfer of the older protocol, which has been making a comeback in the world of hi-res digital audio lately.

Besides the Cirrus Logic chipset, the device is chock full of other high-grade components, as well as providing space for a relatively massive amount of file storage to the tune of 256 GB internally, with an extra 128 GB of available space via the SD card slot.

General performance

First, we have to say that the AK240’s interface (and the rest of the lineup we got our hands on at CES) is a night and day improvement over the first hi-res player we saw from iriver, the AK100. At the time, we gave the player something of a pass as it was virtually the only portable player on the market sending hi-res music files through a top-notch DAC. But the interface was buggy and sluggish, and certainly had the feel of a first effort, if not a beta device.

Name a performance characteristic and the AK240 basically owned it…

Not so with the AK240 (and thank God, given the price point), which moves briskly through its multiple features with intuitive navigation. We wished for a few minor improvements, like a more easily adjustable EQ window, but otherwise had few complaints. We didn’t spend a whole lot of time using the device as a USB DAC for our computer, as it seemed just as easy to connect to the device directly or wirelessly, but it’s a nice option involving a relatively painless setup.

Also fairly pain free was setting up the AK240’s MQS Server streaming on our office PC to access a music catalog wirelessly. Once you’ve installed the software, it’s quick and easy to setup, and it auto-searches for local files and folders in the computer’s music folder. We didn’t have a whole lot of files for the system to track down, but it did the job quickly.

When we added a new folder to the app, the AK240 missed one of the songs that had uploaded to the application. However, a quick click of the Rebuild Library button fixed the issue, and we were able to play back all of the files at full resolution. It should be noted that the application must be up and running on a computer for the player to stream the files.

Some other minor issues we had with the device during our evaluation included a song dropping out during wireless playback, a rather quick drain and slow charge of the battery, and a tendency for the player to heat up a bit over time, especially when connected to Wi-Fi.

Audio performance

We tested the AK240 using a variety of gear, including a pair of AIAIA TMA-1 Studio headphones, the Beyerdynamic T-70, and a pair of Nocs NS900 Live headphones. But the majority of our time was spent with the Westone W40 in-ear headphones, which offer exceptional clarity via a four balanced-armature driver configuration, and hi-fi portability that goes hand-in-hand with the AK240’s design.

Over several days of listening, the AK240 provided an absolutely incredible playback experience, top to bottom. Name a performance characteristic and the AK240 basically owned it, be it dynamic expression, clarity and dimension, depth and texture, instrumental separation, balance, detail, or distortion, the latter of which was virtually non-existent. In fact, we occasionally found ourselves cranking the volume dial louder than we intended, as the audio remained crystalline at any listening level we could handle.

Astell & Kern AK240 back topNot surprisingly, the AK240 excels at high resolution file reproduction. When we called up a 298MHz DSD version of Michael Jackson’s Thriller, the instruments were revealed in a dazzling array of colors that was almost overwhelming at first. The device dug so deeply into the textures and richer details of the tracks, every transient seemed supremely magnified, as if we were shrunken down to examine the massive sonic landscape from a tiny vessel, ala Fantastic Voyage.

The experience started with the snare snap and bass grove at the intro of Billy Jean, each sounding like an amalgamation of a host of instruments that had been layered on top of one another. The bass was especially complex, revealing a glossy attack, a grumbling, almost angry buzz to the sustain, followed by an effervescent release. As the piece opened up, each instrument continued to be drawn out in tangible definition, as if telling a larger tale, complete with a full backstory and ancillary characters. It’s not like we didn’t already respect the great Quincy Jones, but hearing his masterpiece at mastering-level quality revealed his genius in a whole new light.

…every transient seemed supremely magnified, as if we were shrunken down to examine the massive sonic landscape from a tiny vessel…

It was perhaps the AK240’s treatment of the more mortal tracks at 16 bit, 44.1kHz resolution that made the strongest case for this kind of device, however. We spent a long time with the included copy of Echoes, a compilation of Pink Floyd tunes, and if there were ever a good argument that CD quality audio can adequately portray the inherent qualities of analog music, we found it here.

Every instrument was vividly detailed in our sessions, but a few really stood out. Woodwinds, especially saxophones, were at the same time airy and satisfyingly gritty, revealing each breath along the reed in ruffled, sandpaper timbres. Hi-hat and crash cymbals were cut with laser precision, yet lofted with a subtle, elegant touch calling up a live performance. And the complex palette of electric guitar tones was seemingly infinite, cutting freshly revealed colors at an all-new level of dimension, from glossy, bubbled solos that echoed across the image, to crunchy, three-dimensional power chords that would be right at home at a Judas Priest show.

Behind those snippets of insight into our evaluation lay a grand barrage of sounds and poignant moments too numerous to count. We will say that we ended up with enough notes about dynamic expression and instrumental texture alone to account for their own segments.


For all the praise we could shower on the AK240 for its astonishing audio performance, we think its best trait might just be its affinity for taking even CD-quality audio files to 11 thanks to those gleaming Cirrus Logic DACs, ostensibly making the lagging availability of hi-res HD tracks a near non-issue.

However, no matter how much we adored each moment spent with the AK240, we can’t defend its price point. Really, no one can. The number of people who will be able to hear the difference between this device and its lower-tier brethren is a lonely populace indeed. And when you consider that the forthcoming PonoPlayer includes a decent DAC, and also that you could ostensibly grab one of those and a pair of the ludicrously expensive/glorious Audeze LCD 3 headphones for the same price as a single AK240, it’s a very tough sell.

That said, if you’re part of the crowd for whom money is no object, and you want to experience your entire music catalog as though you’d never heard it before, the AK240 might just be your new drug of choice.


  • Unparalleled mobile audio quality
  • Plays virtually any file type
  • Perfected, feature-packed interface
  • Makes every song in your catalog sound better
  • Premium aesthetic


  • No online browsing option
  • Can’t yet upload songs directly from browser
  • Mediocre battery life
  • Expensive, expensive, expensive

Editors' Recommendations

Ryan Waniata
Former Digital Trends Contributor
Ryan Waniata is a multi-year veteran of the digital media industry, a lover of all things tech, audio, and TV, and a…
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