Up to 84% in savings when you subscribe to The Absolute Sound
Logo Close Icon

Begin typing your search above and press return to search. Press Esc to cancel.

Astell&Kern AK500N MQS Network Audio Player

Astell&Kern AK500N MQS Network Audio Player

Korean firm Astell&Kern began its involvement with high-end audio by manufacturing advanced portable music players, from its $499 AK Jr through the premium AK380. Capable of playing native DSD and carrying a $3495 price, the latter is reportedly a spectacular implementation of a portable music player.

Having already established a line of portable players, it was natural for Astell&Kern to bring its technology to a home system. The result is the AK500N network player, a product whose strikingly original industrial design is as innovative as the product itself.  The casework is milled from thick aluminum plates, machined smooth and anodized black or silver. The AK500N looks like an aluminum cube with a faceted front panel, which measures 8.4″ x 9.6″ x 9.4″. (OK, that’s not quite a cube, but it’s cube-ish.) The main body of the AK500N is supported by an aluminum plinth with four feet.

A 7″ touchscreen LCD panel folds flat on top of the chassis—it’s like having a small tablet computer built into the player. When the touchscreen is raised and positioned vertically, the total height of the unit is about 14½”. The touchscreen provides all the controls necessary. Although not really large, the AK500N looks very solid, and at a hefty 25.1 pounds it definitely is solid. And the price tag is equally hefty: $12,000. Due to its dimensions, the AK500N won’t fit on most hi-fi equipment racks; it’s essentially a top-shelf unit—in more ways than one. And what’s that “MQS” thing in the title? Have we added yet another acronym to our lexicon? Well, it seems that Astell&Kern uses MQS to mean Mastering Quality Sound, its term for high-resolution audio. OK, now you know.

Unlike many servers, the AK500N includes an internal DAC. It also provides lots of digital outputs, so you can use an external DAC of your choice, which strikes me as a wise fail-safe provision; no matter how good the internal chip is, there’s bound to be a better one eventually, and considering how fast DAC development is progressing, it may not be too long before a better one is available. Inside the AK500N, two Cirrus Logic CS4398 DAC chips take care of the digital decoding chore. Music file storage is handled internally by solid-state drives (SSD), with up to four drive bays available. The review unit had a single 1TB SSD. Why use expensive SSDs instead of much cheaper hard drives? According to Astell&Kern, the SSD is about five times faster than a hard disk drive, is much more durable, and is silent in operation. I think they also have lower jitter than hard drives. In addition to the SSD storage, the AK500N lives up to its network-audio-player designation by playing files from a NAS drive, which can be as large as your budget permits. You can either plug in an Ethernet cable to attach the unit to your network, or using the small antenna on its back, connect to the network wirelessly, like the Auralic Aries (to which I compare the AK500N later in this review). It can also play files from attached USB drives, either external hard drives or flash drives, and from a microSD memory card—all in all, amazing versatility!

The AK500N plays a variety of music file formats: PCM encoded files include WAV, FLAC, WMA, MP3, OGG, APE (Normal, High, Fast), AAC, ALAC, and AIFF with sampling rates up to 384kHz (DXD) and DSD files including DFF and DSF up to DSD128 sampling rate. DSD files can be played without conversion via DSD over PCM (DoP) encoding. In practice, the AK500N has a software switch to convert PCM files to DSD64 files and play everything back as DSD files. Apparently there was a demand for this feature from the Astell&Kern portable player owners. If PCM au naturel is OK with you, this option is defeatable.

The AK500N uses a battery power supply that provides around seven hours of playback time—long enough for any of my listening sessions. The supply uses a replaceable 10,400mAh/7.4-volt lithium-ion battery. The battery charges automatically when its capacity drops to four percent, or when it’s not playing. An in-line switch mode power supply recharges the battery, which takes about three hours. If the battery is depleted, the power supply, which is very quiet, will run the unit. The AK500N ships with four different power cables, with plugs for different parts of the world, and comes with a stern warning not to use other power cords. Since the battery power supply runs the AK500N, and the power cord only feeds the recharger, it should be OK to skip using a fancy audiophile power cable. Two of the cords look identical, but one has a tag identifying it as usable in U.S. territories.

A feature I appreciate in servers is an internal optical drive that can rip CDs to files on the internal storage. The AK500N’s optical drive rips to either WAV or FLAC formats. Ripping is a one-click operation, with metadata cover art provided from the Gracenote online database. Remember, the WAV format stores very little metadata and takes up nearly twice as much storage space as the FLAC format. However, some folks think it sounds better. The optical drive is accessible through a slot centered on the front panel near the top.

The AK500N can be used to drive power amplifiers through its two variable analog ports, one balanced, one unbalanced. Only one port at a time can be used. Besides the variable analog output, there are two fixed analog ports, which bypass the variable ports. You’d use the fixed ports when you connect the AK500N to a preamplifier or an integrated amplifier—something with its own volume control. There’s no analog input, so you can’t connect a tuner, phonostage, or other analog source. Still, if the AK500 is your only program source—which will probably be the case for a lot of listeners—you can skip a preamplifier in your system and use the AK500N to drive a power amp directly. Astell&Kern has in the works a matching power amplifier that would be just the ticket to use with the AK500N. A large knob, referred to as the Volume Wheel, on the right side of the AK500N lets you control the volume. What about the remote control? One of those is not provided, although the app that offers these functions became available just as this was going to press. There is, however, a very functional substitute from another company, as described later.

There are three headphone jacks on the right lower side toward the rear of the AK500N, one 2.5mm, one 1/4″ and one 3/8″. The 2.5mm jack supports four-conductor balanced headphone plugs. While I appreciate having headphone jacks in a server or DAC, the placement on the AK500N could be more convenient—for instance, on or near the front. But this is a minor quibble. A small button on the right lower side of the AK500N towards the front is the power on/off switch. Because it’s easy to reach from the front, the power switch is convenient. A discreet white LED on the front of the unit shows when the power is on or off. There’s also a small opening just in front of the headphone jacks into which you can plug a microSD card, the type used in camera memories. You can play music files stored on the microSD. Note that this is not the full-sized SD card, but the very small microSD card.

The warranty on the AK500N is one year parts and labor. To me, that seems rather meager for a $12,000 unit.

 

Setting Up and Using the AK500N
My very early version of the AK500N included a multi-language quick-start guide, which, although it was printed in very small type, had enough information to allow you to connect the AK500N to your system and power it up, but not much about using it. A complete, 65-page operating manual is also available via the help screen on the AK500N’s touchscreen. It’s also available online on the Astell&Kern website. It contains a more complete assortment of instructions with copious illustrations, vital to using a computer. Of course, deep down, that’s what the AK500N really is—a very well-disguised computer, but a computer, nonetheless.

Since the AK500N is 14½” tall with the LCD touchscreen in its full upright position, I needed a top shelf or equivalent to place it on. I temporarily removed my laptop computer server from the solid wood table where it normally resides, adjacent to my equipment rack within easy reach of my preamplifier and DAC. Clarity Cables Organic balanced interconnects connected the AK500N’s fixed analog ports to one of my preamplifier’s balanced inputs. Since I use a subwoofer to supplement my main speakers, I couldn’t drive both the sub and the power amp from the AK500N, so I had to use my preamp. A non-audiophile Ethernet jumper connected the AK500N to my home network.

Although the AK500N can stream files via its internal WiFi circuit, Astell&Kern admits streaming is smoother via a wired connection, which is true for most servers. The WiFi connection is useful for the remote-control app running on a tablet. Astell&Kern doesn’t recommend any break-in, but I let the unit run on repeat through its internal DAC for several days, even though it sounded quite good right out of the box.

When I first received the AK500N, its own app had not been finished, so I operated it from its touchscreen. The AK500N is a very complex unit with many options, and I had to call for help in getting up and running several times. A knowledgeable dealer should be able to sort out most user questions. The manual is a good starting point, but I’m not sure it tells the complete story about operating the AK500N. For example, I learned that in order to use a particular set of output jacks, you must turn them on using the touchscreen. (On the screen display they turn blue when active.) That’s simple to do once you know it’s required. You also have to know to turn on the Ethernet connection to use your NAS; again, easy to do once you know it’s required. Ditto for the headphone jacks. I’m sure that part of my long learning curve was due to the AK500N’s extreme flexibility and the capability of its software. For example, it includes a full-fledged equalizer—which I didn’t try.

The AK500N’s display occasionally informed me that several, but not all, DSD files were being transcoded to PCM files before playing. Other times, it told me the same files were being played as DSD files. Since this information did not show up consistently, I suspect this was an error in the display, rather than in the files, as there was never any problem playing them.

Until its own remote-control app became available, Astell&Kern recommended one called Mconnect, designed to work with DLNA servers. Mconnect-H (H is for high-resolution) found the MinimServer and TwonkyServer programs running on my Network Attached Server (NAS) drive, and let me choose which to use. When I selected MinimServer, Mconnect-H let me see and play the music on my NAS drive. Unlike most music-player apps, Mconnect-H is not free; it was a whopping $3.99. Hey, if you can afford $12,000 for the AK500N, what’s another $3.99? I tried a variety of other free DLNA remote control apps, but none worked as well as Mconnect-H.

During its stay at Casa Forrester, I used the AK500N to rip several CDs. The first CD was Michael Newman’s Guitar Pleasures [Sheffield Labs SLS-504]. This collection of music for solo guitar, guitar duet, and string quartet has a total recorded time of just over an hour. After I cleaned it thoroughly with BlueMaxx CD cleaner, I inserted it into the AK500N’s optical drive. The AK500N screen asked me if I wanted to rip the CD to FLAC or WAV format (I picked FLAC), and then it scanned the Gracenote database to identify the CD’s tracks and cover art. That took about a minute, after which the ripping process started. I’ve tried several servers that rip CDs, and the AK500N was by far the slowest—it took 14 minutes to rip a single CD. (The last server I auditioned was the Digibit Aria, which took around 4 minutes to rip a CD, and scan five databases for metadata.) Although the AK500N’s ripping speed was set at Fast, the drive was silent during the ripping process. I didn’t try playing music while the ripping was in progress. The CD was ejected when the process was completed. I immediately played the ripped digital file, and it sounded great. The next CD rip automatically selected the FLAC format. If I wanted to switch to WAV format, I could have gone into the settings menu and changed my preference.

The AK500N can play files from a NAS, from the internal SSD, from external USB drives (both USB flash drives and USB hard disk drives), and from microSD cards, but it can’t play files from a smartphone via a Bluetooth connection. The instruction book tells you how to pair the AK500N with a Bluetooth remote control; however, that didn’t work for file playback. Yes, I had to try it, even though it wasn’t supposed to work—and it didn’t.

Ripping CDs is a valuable feature, but how do you play existing computer-audio files—including high-resolution files (high-sampling-rate PCM files and DSD files)? If you have a network with a NAS connected, the easiest way is to play it from there. But if you want to copy high-resolution albums to the SSD, you must connect a computer to the AK500N using only the provided USB cable plugged into the USB type B connector in the back of the AK500N. The player will show up as a portable device on the computer, and you can copy albums from the computer to the AK500N’s internal storage folder.

If you want to copy songs from the NAS to the SSD, first find the song in the NAS library or in a folder. Then press the appropriate icon and a screen will ask if you want to download the song to the SSD or add it to the Now Playing list. If you press Download, the song will be added to the that subfolder inside the internal storage folder, and placed in the correct album with the correct cover art. Well, usually. The cover art for a few of my more esoteric albums apparently couldn’t be found in the Gracenote database. This procedure only worked for copying single songs on the NAS to the SSD.

Although an SSD is more reliable than a hard drive (no moving parts to break), you should still back up the SSD contents in case your AK500N is damaged by a disaster such as fire or flood, or is stolen. Again, you’ll connect your computer to the AK500N with the USB cable, then reverse the previously described copying process, and copy music from the internal storage folder on the AK500N to the computer—or more likely, to an external drive attached to the computer.

To play headphones from the AK500N, you must first turn on the appropriate headphone jack. I first tried some HiFiMan HE-400 headphones. Since they are the least sensitive ones in my collection, they constitute a challenge for a headphone amplifier. The AK500N would just barely drive the HE-400s to acceptable levels; on Shelby Lynne’s DSD album Just a Little Lovin’, recorded at an unusually low level, I had to turn the AK500N’s volume up all the way. I’m sure some listeners would need or at least prefer more power output from a headphone amp. I figure that if you’re into low-sensitivity ’phones, you already have a headphone amp capable of driving them. The AK500N’s headphone amplifier drove my more sensitive Audeze LCD-X just fine, producing deep, detailed bass and a bit of sparkle in the treble.

 

Sound
Because the AK500N is so complex and flexible, a complete review must evaluate how it sounds through all sources. So I evaluated the AK500N playing music files from its internal SSD, from a USB portable drive plugged into the rear USB jack, and from my NAS. I didn’t have a microSD card available. My expectations were that files from the SSD would sound best, and files from the NAS would sound worst. I listened to its performance with speakers, and with headphones. It kept me busy! (I know you feel sorry for me having to listen to music all those different ways.)

I have listened to “Folia: Rodrigo Martinez 1490” from Jordi Savall’s La Folia 1490-1701 (ripped in AIFF format from Alia Vox AFA 9805) so often it must be imprinted on my cochlea. Usually, when I listen through a new component, the reproduced sound has areas that stand out, others that are merely OK, and occasionally, some that are lacking. Not so with the AK500N; everything came together to provide one of the best listening sessions I can remember. From the portable USB drive, the bass drum descended as deeply as I’ve ever heard it, but the details of percussionist Pedro Estevan whacking the bass drum were depicted with special clarity. Savall’s viola da gamba part was also very detailed, with harmonics realistically depicted. Abundant details about other percussion instruments—castanets, woodblock, cascabels—were also retrieved, but not by spotlighting the high frequencies. The clatter of castanets in particular was just spectacular. Dynamics, from subtle microdynamics to more abrupt changes, were clearly delineated, giving the piece an exhilarating realism. This was perhaps the most realistic and exciting playback of this piece I’ve ever heard—and I’ve heard some pretty good ones.

When played from the internal SSD drive, the piece sounded essentially the same. I had to strain to detect a difference. I thought the bass drum had the same power and impact, but descended just a little bit deeper and exhibited a smidge more detail. The impact of each whack of the mallet could be felt. I also went away with a heightened appreciation for my subwoofer. Similarly, the percussion instruments were extremely well defined; perhaps an occasional additional detail came through. Savall’s viola da gamba seemed a bit more detailed. Dynamics were at least as well defined. All in all, playback from the internal SSD and from an external hard disk drive made for very close competition, with perhaps a few items in favor of the SSD.

Finally, totally confounding my expectations, I preferred playback from my NAS over my home network to both the other sources. It seemed to combine the best features of the other two: low-end depth and impact were just as great, and I heard just as many bass details as from the SSD and more treble detail than from the USB drive. Microdynamics were just spectacular; the music sounded like a spring being wound up, then suddenly released. While I’ve heard this characteristic from other servers, it’s seldom if ever been as starkly defined as with the AK500N.

The eponymous track from Shelby Lynne’s album Just a Little Lovin’ [DSD64/DSF, Acoustic Sounds] opens with a powerful bass riff, and the AK500N did full justice to the song’s power, but also depicted that instrument’s details. Lynne’s vocals were nuanced and expressive, and the way the AK500N captured her voice’s texture revealed those qualities superbly.

On “Miserere” from The Tallis Scholars’ Allegri’s Miserere & Palestrina’s Missa Papae Marcelli [24/96 FLAC, Gimell], the spatial characteristics of the recording venue were clearly portrayed. The solo group behind the main choir was free of the smear I sometimes hear; the distant group was virtually as clear as the front group; however, certain reverberant cues made it clear the distant group was behind the main group. The tenor in the main group sang without distortion or overload.

One of my favorite LPs is Ernest Ansermet leading the Orchestre de la Suisse Romande in Falla’s El Sombrero de Tres Picos and Chabrier’s España, Rhapsody for Orchestra. That recording has recently become available as a DSD128 recording from High Definition Tape Transfers. On the AK500N, the spaciousness of the recording was quite amazing; when the castanets first clattered in the intro, it sounds like they extended from wall to wall in the recording hall. Dynamics were quite pronounced, as on the LP. Sometimes, battery-powered equipment may suffer in this area, but not so the AK500N. Yet distortion and overload were minimal, so everything sounded super-clean.

Comparison
The Auralic Aries is a streaming device that connects a NAS to a DAC (or a USB drive to a DAC). It uses a server program running on the NAS, renders (plays) the files chosen for playback, and sends the decoded bitstream to the DAC. The unusual thing about the Aries is that it can connect wirelessly to the NAS. However, to try to create an identical test environment, I used it wired to my network. I used my PS Audio DirectStream DAC with an Audience Au24 SE USB cable connecting the Auralic to the DAC. Auralic provides a free remote-control app called Lightning DS. The cost of the Auralic Aries, the DAC, and the cable is $8573.

On “Folia: Rodrigo Martinez 1490,” the AK500N stomped the Auralic/PS Audio with detailed, subterranean bass. OK, that’s an exaggeration; it wasn’t that the Auralic/PS Audio’s bass didn’t extend just as deeply, but the AK500N produced noticeably more power and impact. The reverberation from the opening cascabels seemed to resonate a little more in the recording space through the Auralic/PS Audio; this setup combo also seemed to illuminate the percussion clattering away in the background with just a tad more detail. On this piece, normally a great tool for distinguishing between components, the differences in sound were much less distinct than usual.

On “Just a Little Lovin’,” the Auralic/PS Audio again produced bass that was deeply extended, but relative to the AK500N, noticeably less powerful and punchy. Yet I could hear a very slightly more nuanced performance through the Auralic/PS Audio combination.

On “Miserere,” the distant solo group sounded virtually identical to the AK500N, but I thought I could hear very slightly more texture in the reproduction of the tenor, so that I could discern a barely perceptible vibrato. There was really not much to distinguish between the two systems’ sonics on this piece.

Falla’s El Sombrero de Tres Picos sounded less spacious than on the AK500N. The castanets didn’t seem to spread out in space as much, and the dynamics were not as punchy.

The most noticeable difference between the Auralic/PS Audio and the AK500N was the latter’s more powerful, impactful bass. It was not an overwhelming difference; the PS Audio, with its Pikes Peak operating system update, has extended bass. The AK500N also seemed to throw a more spacious soundstage. Both excelled at reproducing instrumental and vocal harmonics, and, again, were thankfully free from distortion and overload, so the sound was never strained.

 

Bottom Line
Predictably, when I told visiting audio buddies how much the AK500N cost, their reactions ranged from shocked shakes of the head to crude expletives. And they’re right; it is quite expensive for a music player. But you get a lot for your money. Its styling is unmatched, and I think that’s important; if you spend a lot on audio gear, you should expect to take pride in its appearance, and I can’t think of any other player that looks as good. It also offers a huge array of features—the ability to play computer audio files from an internal source, from an attached USB drive, from a microSD card, or from a NAS drive—that pretty well covers all possibilities except Bluetooth. And its ability to rip CDs directly onto its internal drive is a very convenient feature. It has a wide assortment of digital inputs, and digital and analog outputs. Included in the analog outputs are several headphone jacks, which, while they won’t drive some of the more power-hungry ’phones, do sound excellent with more normally sensitive ones. I doubt that anyone would buy an AK500N just to use as a headphone amplifier, but it’s very convenient to be able to listen to music that way without having to turn on your whole system.

Unlike several other combination servers and DACs I’ve tried, the AK500N doesn’t skimp on its DAC; so you won’t soon need to spend money on an external unit and connecting cable. And you don’t need an extra shelf on your equipment rack for an external DAC. You may need a top shelf, or at least one that’s very tall, however, to use the touchscreen in its full upright position.

Of course, all those features would be moot if the AK500N sounded mediocre, or even merely very good. But in fact, it sounds spectacular; in many ways, the best player I’ve heard. In particular, the bass, from all digital inputs, is positively earth-shaking, with lots of detail and impact. Treble was smooth and harmonically rich, with realistic detail. Dynamics—micro and macro—were right up there with the best I’ve heard. Soundstaging is at least as good as anything I’ve heard in my system.

I’m sorry I won’t get to see the Astell&Kern remote-control app, but Mconnect was really quite flexible, allowing me to use the full feature set of the player, something that many dedicated remote apps can’t manage to pull off. As you might expect for something as complex as the AK500N, there’s a bit of a learning curve, but everything worked very positively and securely. With some players, some of the controls are too sensitive, or seem to work only sporadically—not so with the AK500N. And although it’s a somewhat personal issue, I found the control buttons on the app to be logically designed, so that part of the learning curve was pretty shallow.

In summary, the Astell&Kern looks strikingly beautiful, sounds rich and powerful, and is easy and straightforward to use. Does that make it worth $12,000? The answer to that is necessarily a personal issue, but I can’t identify a network audio player, or combination of a server, DAC, and cable that matches it at its price level.

SPECS & PRICING

DAC: Cirrus Logic CS4398 x2 (Dual DAC)
Storage: Solid-state drives 1TB, 2TB, or 4TB
SNR: > 100dB
Digital out: AES/EBU x1, BNC x1, coaxial x1, optical x1
Digital input: AES/EBU x1, BNC x1, coaxial x1, optical x1
Analog out: Balanced (XLR) x 2 L/R pair, unbalanced (RCA) x 2 L/R pair
Fixed output level: 3V (RCA, balanced)
Variable output level: 7.5V RMS (RCA)/10V RMS (balanced)
Channel separation: > 135dB @ 1kHz
USB: Type A (Host) x2, Type B (Device) x1
USB DAC: USB Audio Class 2.0, DSD64, DSD128, PCM
Network: Wi-Fi 802.11b/g/n (2.4GHz) and Ethernet 10/100/1000, DLNA (DMS, DMC, DMR)
Supported audio formats: WAV, FLAC, WMA, MP3, OGG, APE (Normal, High, Fast), AAC, ALAC, AIFF, DFF, DSF
Sample rate: 8kHz to 384kHz (8/16/24 bits per sample); DSD64 (1-bit 2.8MHz), DSD128 (1-bit 5.6MHz)
CD ripping audio format: WAV, FLAC; selectable at time of rip
Dimensions: 8.4″ x 9.6″ x 9.4″
Weight: 25.1 lbs.
Price: $12,000

ASTELL&KERN/IRIVER INC.
39 Peters Canyon Road
Irvine, CA 92606
(949) 336-4540
astellnkern.com

Vade Forrester

By Vade Forrester

More articles from this editor

Read Next From Review

See all

Adblocker Detected

"Neque porro quisquam est qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit..."

"There is no one who loves pain itself, who seeks after it and wants to have it, simply because it is pain..."