June 2015



World Premiere!
Astell&Kern AK380 Battery Powered Portable Media Player / DAC Review
With a bit of comparo using the AK240 and Sony NW-ZX2 thrown into the mix.
Review By Steven R. Rochlin

  Only a few short days ago one, if not the leader in digital portable media players, announced their new AK380 ($3500) battery powered stereo portable digital audio player / DAC. Like the AK240 ($2500) before it (see my Astell&Kern AK240 review here), the GUI is completely custom. This is unlike the Sony NW-ZX2 ($1200) that relies on bootstrapping onto an old version of the Android (4.2.2, with no plans from Sony to date for upgrading to the fast and more secure to 5.x / Lollipop now widely available). Whilst the AK240 was the company's top model, last week the Astell&Kern AK380 portable media player now takes the top spot. The AK380 is a significant upgrade in many ways. From the moment I put in my specially-prepared reviewer's 64GB SD Card and having a first listen with the JH Audio Roxanne CIEM, it was immediately obvious there were audible improvements over the Astell&Kern AK240.

Technical
Astell&Kern's AK380 employs a 32-bit/384kHz DAC plus "Bit to Bit Playback, Native DSD Playback, 20 Band EQ in 0.1dB steps, VCXO Reference Clock (200 Femto seconds), Extendible Docking connector, AK Connect App, and Metal-touch sensor Home button". The previous top-line AK240 uses two Cirrus Logic CS4398 whereas the AK380 has two AKM AK4490 chips. In fact the AK380 has native support for 32-bit/384kHz PCM playback and of course up to DSD128 (1-bit 5.6MHz). Furthermore, Astell&Kern now provides a full ecosystem that makes it an extremely simple task of ripping discs and docking the AK380 for recharging plus true XLR balanced output to feed your home stereo system. Getting back to the AK4490 DAC chipsets, like the AK240 with the pair of Cirrus Logic CS4398, the AK380 is a dual-DAC design so that each channel, right and left, has their own dedicated DAC. This provides a dual-mono design and aids with the AK380's extremely high 130dB channel separation with the unbalanced output (an astonishing 135dB balanced!). Will say right off the bat that channel separation and soundstage width sounds to me to be far higher than the Sony NW-ZX2 i reviewed at this link. Good luck finding out information about the Sony, as the company refuses to tell me about the output impedance and other very important technical items. Shrouded in mystery, and maybe some magical DSP (digital signal processing) pixie dust, the Sony NW-ZX2 seems to employ some tricks to sound good whereas the Astell&Kern provides complete technical information and solid engineering using the latest and greatest technology to achieve excellence.

While self-proclaimed audiophiles might not use Bluetooth for listening to music due to it not handling high resolution music, many of us do use Bluetooth from time to time. With that said, Sony's NW-ZX2's older design uses Bluetooth 3.0 whereas the Astell&Kern AK380 has Bluetooth 4.0. Sony continues their proprietary ways with the company's Bluetooth LDAC codec, which takes your music streaming upwards of a three times greater bitrate than typical Bluetooth streaming. LDAC provides 96kHz sampling rates and more efficient coding for CD-quality wireless sound. Of course you'll have to buy a partnering Sony unit to take advantage of this so you can forget the LDAC for anything other than another Sony product that has mating circuitry. Perhaps if Sony did not like to muddle the waters so much over the years, as DVD-Audio and other formats were gaining steam nearly a decades ago as Sony was pushing their then new DSD format, music lovers worldwide would have been able to enjoy many more high resolution albums today... instead of a nearly decade long delay. Be that as it may, better late to the party than never, I guess (grumble grumble).

User Adjustments
When it comes to user adjustments such as equalization, the AK380 completely obliterates Sony's NW-ZX2 paltry five-band EQ plus 'Clear Bass' adjustment, which is adjustable in a very rough 1dB setting instead of far finer levels as desired by recording engineers worldwide. Astell&Kern's AK380 has a staggering 20 band EQ, which is adjustable in an impressive 0.1dB levels! Furthermore, with the Sony NW-ZX2 you have some typically (usually) useless presets for the EQ plus only three user-adjustable settings; whereas the AK380 provides nearly limitless custom EQ setting plus you can assign each final EQ customization with a name. Thus, if you're like me and have multiple headphones, multiple CIEMs and use the unit within cars, I can easily have a custom setting for each one and name them so I know which setting was painstakingly set for each headphone, CIEM and vehicle. If a company is going to dedicate extensive research and development to produce a reference level portable media player, naturally they should expect the unit to be enjoyed within a wide array of situations. This is especially true at these price levels. Unlike 120V/220V dedicated home audio units, once you are designing portable audio hardware, your engineers should naturally expect customer to take their hard-earned dollar investment and use it as much as possible in as many places as possible.

When it comes to internal amplification, there really is no comparison. The Sony NW-ZX2's paltry power output of only 15 mW per channel at an impedance level the company repeatedly refuses to disclose (I asked Sony's chief engineer personally), Astell&Kern's AK380 has an output of 2.1Vrms in unbalanced mode and 2.3Vrms in true balanced configuration. This also brings up another Sony quagmire, as the NW-ZX2 is not truly balanced and thus merely uses different grounds for those who use balanced headphone and IEM cables. Yes there are benefits to having two grounds, yet you do not get the true benefits of a fully balanced circuitry. As for the far higher output for headphones, the AK380 can drive nearly anything from inefficient planar magnetic headphones to highly sensitive CIEMs. In fact there Is an amplification output adjustment level on the AK380 so that the volume output setting ensures you get the maximum flexibility for the given sensitivity of whatever you hook to the unit for listening with 100 levels of adjustment. The Sony NW-ZX2 has a much lower audio amplification output that can only drive highly efficient headphones and IEMs / CIEMs. As for levels of volume adjustment, you get a very usable 60 levels with the Sony NW-ZX2 and am not one to nit-pick this too much as with such low output on the Sony, 60 different levels should be sufficient for virtually everyone.

Start Up And GUI
From turn off until being fully usable, boot-up time for the AK380 is impressively fast! It is faster than the AK240 and is far faster than the Sony NW-ZX2, which Sony always needs to re-scan all your music each and every time you turn on the unit after it has been powered off. Hopefully Sony reads this review and begins to realize their unit desperately needs a software update with better EQ, proper displaying/handling of album art, and many other features that many others provide. Yes the AK380 is nearly 3x the price of the Sony, yet units far less costly than the Sony offer more features. Sony could easily improve their player via GUI / software updates as the core hardware seems quite usable. Sony has incredible financial resources and programmers at their disposal, and so they started with a good hardware platform that simply needs to have better software and features as they need to better understand their customer's demands and, dare we ask, exceed it. Sony code-monkeys unite and let the company know how well you can improve the NW-ZX2 to at least be equal to units costing far less than the NW-ZX2's $1200 entry fee.

Astell&Kern has done their customers a great service at offering reference quality DAPs (digital audio players), plus they now have a wonderful ecosystem to take advantage of the class-leading internal memory of 256GBs, plus a slot for SD memory card just like the AK240. Sony's NW-ZX2 has 128GBs of internal memory plus an SD card slot capable of handling another 128GB. So a grand total of 256GB for the Sony and 384GB for the AK240 and AK380 battery powered portable media players. With Sony pushing their Hi-Res Audio initiative, they needs to think about pushing the NW-ZX3 up to at least 256GB internally, and perhaps 384GB internally would really be a great improvement within their Next Gen unit.

FYI: Am not doing many comparisons adding in the AK240's hardware data as have much of this information within my previous review of the Astell&Kern AK240 so you can feel free to read about it there.

Ecosystem
Astell&Kern, like Sony, offers a power docking station for their portable media players. Due to such limited headphone amplification output, Sony also offers an external amplifier with DAC. If you use the DAC section, it seems to lose some of the DSP that makes the NW-ZX2 sound so magical. Thus you really can use any manufacturers external amplifier for analog out of the Sony to the input of any external amplifier unit. If you use the Sony NW-ZX2 on its own and you must use their provided Music Player program, there are DSP modes that can change the sound the unit produces. Many have noted that using different Android programs or Sony's external headphone amplifier appears to eliminate this DSP benefit. Astell&Kern employs pure high-end parts and circuitry to achieve high-end sound quality and thus no DSP tricks other than the previously mentioned extremely flexible EQ is provided. In addition to a dock, Astell&Kern now offers an easy way to rip your disc directly to the AK380! Simply insert a disc into their external unit and their new ripper will read the digital bits off your disc and store them within the available memory on the AK380. Those new to portable media players will rejoice at how easy this makes ripping their prized music collection. Furthermore, there are XLR balanced outputs on the back of the dock unit for sending as true balanced output to a high-end audio system.

Before I forget, you can use the AK240 and AK380 as an external DAC for your computer, whereas the Sony surprisingly does not offer this capability. All three units can be used to send a digital signal out of the player to feed an external DAC. The Sony unit needs a special $50 cable (Amazon price sourced, or around $32 plus shipping from eBay) called the WMC-NWH10 USB whereas the Astell&Kern units only need a standard micro USB to USB cable you probably have laying around your home right now. With the Astell&Kern AK380 Connect app for iOS and Android-based smartphones and tablets (coming soon), you can control playback on the device and stream music located on your device directly to the AK380. Sony is left in the dust here. Of course I love chachkies so all those nifty accessories and 'toys' are always welcome by Yours Truly. For the Sony NW-ZX2 I already have three extra charging cables (from ANiceS on Amazon for $10), the CKL-NWZX2 leather case ($100 plus shipping at eBay), the aforementioned WMC-NWH010 USB digital output cable plus the FiiO L50 analog line out cable ($20 from B&H Photo). So yeah, I love all those accessory bits and am addicted to cheap and fun chachkies.

As a side note, you should see the two massive drawers filled to the brim with cables 'n' bits on the first floor of my home. Then there is the four massive boxes filled with a plethora of cables and bits in the basement. Then another section in the basement with.... If you need a cable or adapter, no matter how vintage or strange, those with built-in resistance, female-to-female USB, balanced to unbalanced, step-up transformers for this, 1:1 transformers for impedance that, and the other things for splitting the Apple/Android jack to separate the mic input from the stereo output... odds are i have one here. If it's not here, i'll just reach into my very heavy box of raw connectors and heat-up the temperature-controlled Weller and fabricate one up for you. Did you want the cable Techflex'ed? How about heat shrinked for a professional look? Here's a shout-out to my Facebook friend Erei Chua, who is perhaps the only guy who is crazier than me when it comes to cables 'n' tweakin' portable audio. Erei, i mean that is a cool bro way of course. Keep rockin' it bro!

Astell&Kern AK380 Operation And Controls
They say a picture is worth 1000 words and so here many pics. Those who are familiar with the AK240 will feel right at home here. I'll cut to the chase and say that the unit operates fairly fast, has a bit of lag if your scrolling up and down on folders/songs and when you press the touchscreen to choose a song there is about a one second delay until the song begins playing. Astell&Kern said this will be fixed within the upcoming firmware update, which will be within the unit at next week's T.H.E. Show Newport 2015. The Sony NW-ZX2 is faster when you press the touchscreen and the song begins to play. I really like the GUI Astell&Kern uses and the folder art, unlike the Sony, always appears when you have some within the appropriate folder. Of course there are the usual side buttons for Back, Play/Pause, and Forward. Just as with the AK240, there is a small sensor on the bottom center to bring you back to the main menu no matter where you are within the GUI's menu system. Firmware is easy to update online once you have the AK380 connected to Wi-Fi and there is now full DLNA 1.0 support. This means you can easily use Wi-Fi and DLNA to find your NAS unit(s) and thus pull music from your NAS system. Alas, was not able to test/verify how well the AK380 can pull music from a NAS drive as only had about 100 minutes using the unit within the HIGH END show in Munich. All in all, if you love the AK240 OS, the AK380 will seem nearly the exact same with a few added features and benefits.

Before I forget to mention, the AK380 uses a 4" TFT-LCD screen (480 x 800 resolution). The casing is made from duralumin, aircraft grade aluminum body, and has both unbalanced and true balanced analog outputs of the top of the unit.

In Use And Sound
The audition, mainly with high resolution audio files, I did note that the center rear of the unit only got slightly warm to the touch. So how does the AK380 compare to the AK240 you ask? Well, the AK380 has a smoother, yet faster way of handling transients. This increases the feeling of music reproduction ease while also making instruments more immediately recognizable. The highs seem to have a more natural 'hang time' and extension than the AK240. Stereo separation, even with the JH Audio Roxanne CIEM with stock non-balanced cable i previously reviewed, is much improved over the AK240. In fact the stereo separation and soundstage was the very best of the three portable media devices. The difference was not subtle to my ears, as the AK380 is the very best stereo separation my ears have heard on a portable device. Wide, and also very nicely deep, too. Instrument layering is also improved on the AK380 over the AK240 and I'd say about equal to the Sony NW-ZX2, with excellent inner resolution to follow individual instruments during both intricate and small ensemble passages.

The AK380 has more amplifier punch and drive behind it, with the Sony being more like a fabled top quality tube amplifier. This is especially true within the uppermost frequencies, where the Sony has a natural extension without harshness, though did hear a tiny bit of harmonic crunch with the AK380. Here is where I know some of the music files I have do indeed have crunch, and so the AK380 is more honest whereas the Sony probably uses some DSP to modify the way audio sounds so it never gets to audibly aggressive. It is akin to the Goldmund Apologue Anniversary self-powered floorstanding speakers ($500,000+) where no matter how much you pushed the speakers or how aggressive the music, there was some internal circuitry/DSP ensuring it always sounded musical and pleasant. As much as I may want the AK380 to shine, the Sony remains a 'friendly to the ears' champion in the frequencies from 3000 Hz on up due to the way it modifies the audio to always sound more musical.

Wait? Did a reviewer just say he wants his music to not sound exactly as it is and, instead, have some DSP in the signal's path that modifies the music to sound more musical? Why yes, you did interpret that correctly. The Astell&Kern AK380 is far more honest, with the Sony NW-ZX2 being more musical. Whilst I am a bit apprehensive to say the AK380 is like a Pass Labs amplifier and the Sony NW-ZX2 being more like a Nagra Audio tube amplifier (and all generalizations are wrong of course), hopefully you get a feeling for what message I'm trying to convey here in more familiar audio terms. Sadly, no amount of EQ can 'solve' it for the AK and yes I tried. Speaking of EQ, the difference between the AK380 and NW-ZX2 are nearly night and day.

When it comes to EQ, the Sony NW-ZX2 is left on the street as road kill when it comes to the ability to naming presets, preset quantity and adjustability. On one hand, the NW-ZX2 is very well laid out, they have the adjustable frequencies at good chosen center spectrum and their Clear Bass it akin to the dbx Subharmonic Synthesizers. For those unfamiliar, what the Clear Bass effect does is take whatever deep bass there is within an audio signal and to keep this description overly simplified, it synthesizes lower octave sound. Many dance clubs love using the dbx Subharmonic Synthesizer device and here is what bass freaks probably will fall in love with the Sony NW-ZX2. Is it 'real' sub-bass? Ahhh, well, perhaps no yet it is a DSP options that Sony offers whereas Astell&Kern choose the honest-to-the-signal path of audio.

Heard many different tracks during my audition, yet here is a specific example that many people know well. I'm using Michael Jackson's "Thriller" in high resolution DSD 2.8224 MHz for those curious. This known crunchmeister recording has driving bass and some fast and clean sound in virtually all aspects plus a very wide soundscape. The bass on the Sony is far deeper and smoother thanks to DSP, yet the AK380 is tighter and cleaner. We're talking 100Hz-ish on down with the AK380 versus 50Hz-ish centered on down with the Sony due to the Sony's DSP. The door opening at the beginning of "Thriller" is wider and more evenly resolved across the soundscape with the AK380 than the NW-ZX2. The creaks of the door, resolution wise, is nearly the same with perhaps a nod going to the Astell&Kern AK380 as it sounds a bit cleaner. The footsteps also have a bit more accurate, to my ears, sound on the AK380 than the NW-ZX2. Once the rhythmic driving deep bass begins, the differences between the two units become very audibly apparent. The AK380's audio output using the JH Audio Roxanne CIEM with bass potentiometer set to neutral is more towards mastering engineer accuracy whereas the NW-ZX2 is more like a dance club bass throbbing. If the AK380 offered DSP plug-ins such as a dbx Subharmonic Synthesizer then I have a feeling the AK380 would easily trounce the NW-ZX2 here for all you bassheads out there. Me? Well, both are valid renditions and I prefer the AK380 for its accuracy and at higher volume levels the amplification has far more headroom and ability too. The Sony almost seems to run out of steam if I turn the volume up high. Before you ask, the Noble K-10 are in service for a lube and oil change... or it could be that I stupidly dropped them and, well, um, you see, it is like this, they needed a little TLC. If you're using less efficient IEMs or headphones, within the Astell&Kern Ak380's menu is a gain setting, plug of course there is an optional external amplifier hardware option as part of the overall ecosystem.

The Noble K-10 CIEM are more sensitive than the JH Audio Roxannes, and so the amplifier's lack of output on the Sony becomes far more important here. Why Sony made a PMP with so little output is anyone's guess, unless they want to sell external amplifiers to move another SKU or some such. The Noble K-10's also have deeper clean bass imho than the Roxanne CIEMs, and so here is again where the AK380 is a complete package. Note that I was using the low output setting of the AK380 with the JH Audio Roxanne CIEMs, as you can adjust the amplification section output to make the 100 volume levels at their optimum. There is no doubt the Astell&Kern AK380 is far more capable in driving a wide variety of headphones and IEMs than the Sony. There is no contest, as it is not even close in easily choosing the AK380 as the undisputed winner by a landslide.

Song after song were compared from Pink Floyd and The Alan Parsons Project in CD resolution and high resolution to Rammstein on mp3(!). Of course more DSD such as the ever-popular David Elias. If I were one to seek the truth in audio and the very best of resolution, than the AK380 wins hands down. Even when I use the Onkyo HF Player (unlocked) to avoid as much of the Sony DSP as possible, I could easily discern the resolution is higher on the AK380. With the AK240 it was not such an easily clear-cut decision, yet with the AK380 it is not even close as Astell&Kern has once again reached the pinnacle of portable media player capability. That always-prized audiophile transparency goes to the.... Envelope please... and the winner is the AK380. PRAT (pace, rhythm and timing) is almost a crapshoot with the Sony NW-ZX2. Slightly different, yet both units are very impressive. The Sony might, maybe, perhaps get the nod for boogie factor by a teeny tiny smidge, yet the AK380 has such a clean and solid delivery over the NW-ZX2 that it may simply come down to your own preference of exactly what PRAT is and how you personally define it.

Look! There's An Elephant In The Room!
Ok, let us get this said and done right here and now. The Astell&Kern AK380 will set you back $3500 whereas the Sony is $1200. Battery life of the Sony after charging is leagues ahead of the AK380. The NW-ZX2 also handles TIDAL and other online music services and, frankly, any Android app you choose to use. The AK380 is a true purpose-built edge-of-the-art 32-bit/384kHz and native DSD capable unit (and we must remember that Sony's NW-ZX2 surprisingly does not handle Sony's proprietary DSD format natively). No matter how one slices it, the question will be raised if the AK380 is three times better than the NW-ZX2. For usability and flexibility there is no contest as the NW-ZX2 wins due to being Android-based. If we're talking battery life on a single charge, once again the Sony wins. Yet when it comes to delivering the ultimate in accurate sound quality, an ability to drive virtually all headphones and IEMs, plus the ability for use as an external DAC, the AK380 takes the prize handily. If you use headphones or IEMs that are not power efficient, the Sony is almost a waste of your money imho because you are missing out on the ability to take advantage of their built-in Android Music Player's DSP. Unlike the Sony NW-ZX2, the AK380 is a true balanced unit and handles DSD natively. It also plays the ultimate in today's highest of resolution digital audio music and any digitized audio file for the foreseeable future. Furthermore, you can buy an external dock for the AK380 that provides XLR balanced output to feed your home audio system. In addition to that, Astell&Kern offers a disc ripper for the AK380 that makes copying your discs to the AK380 a breeze.

The Sony sounds really musical, has great battery life and love it when traveling and within my GTC automobile. Sony's Clear Bass equalization adjustment really has a wonderful way with certain pop/dance music too. Same goes for classical music with organ when they use the 32' pipes. Yet if you want honesty and are more the mastering engineer type and honesty in music reproduction over DSP tricks, the Astell&Kern AK380 is an easy choice. It provides so much more EQ settings and memory settings for those of you who truly take their portable media players into multiple situations.

Grand Finale
As my time with the Astell&Kern wrapped up, with a few others within the industry also doing the comparo with me as they borrowed the Sony NW-ZX2, I won't say who said what as they work for certain companies so prefer to keep their comments private. Did my best to be very discrete while conducting this comparo at Astell&Kern's booth in Munich and humbly thank them for allowing me the time with their incredible new unit. One person said they liked the NW-ZX2 better. And before you ask....

So where does that leave the AK240? I haven't mentioned it much within the review because, well, the resolution of the Sony seems a tiny bit better and there is much else equal or nearly so that it is hard for me to recommend the AK240 to my ears and preferences. My previous AK240 versus NW-ZX2 comparo review tells the story there. Yet swap out the AK240 for the AK380 and the AK380 makes this an easy choice if you forget about costs, do not care about limited battery life per charge and don't plan to use TIDAL or other Android-based apps. The ultimate portable media player for recording / mastering sound quality is the Astell&Kern AK380 hands down, everything else is settling for a compromise. When it comes to transparency, accuracy and the ability to drive a wide variety of headphones and IEMs the AK380 is clearly the winner here. Add in the fun extras such as a dock with true balanced XLR output plus a disc ripper and you have a seamlessly integrated ecosystem fit for a King.

As Mel Brooks likes to say, "It's good to be King." As always, in the end what really matters is that you...

Enjoy the Music,

Steven R. Rochlin

Note: Astell&Kern have updated their firmware. You can read comments and more listening notes within my T.H.E. Show Newport 2015 report.

Specifications
Type: Portable stereo digital audio player / DAC
Display: 4" WVGA (480 x 800) Touchscreen
Frequency Response: 10 Hz to 70 kHz
Signal To Noise ratio: 116dB @ 1kHz unbalance  and 117dB @ 1kHz balanced
Crosstalk: 130dB @ 1kHz unbalance and 135dB @ 1kHz balanced
THD+N: 0.0008% @ 1kHz unbalance and 0.0007% @ 1kHz balanced
Output Impedance: Balanced out 2.5mm (1 Ohm) and 3.5mm (2 Ohm)
Maximum Output Level: Unbalance 2.2Vrms / Balance 2.3Vrms (Condition No Load)
Supported Audio Formats: WAV, FLAC, WMA, MP3, OGG, APE (Normal, High, Fast), AAC, ALAC, AIFF, DFF, DSF
Sample Rate: PCM: 8 to 384kHz at 8 to 32 bits per sample
DSD Native: DSD64 (1-bit 2.8MHz) and  DSD128 (1-bit 5.6MHz) stereo
DAC: Two AKM AK4490 (Dual DAC)
Decoding: Support up to 32-bit/384kHz Bit to Bit Decoding
Input: USB Micro-B input for charging & data transfer 
Connection Mode: MTP (Media Device)
Output: 3.5mm stereo analog / optical plus 2.5mm balanced analog (4-pole supported)
Wi-Fi: 802.11 b/g/n (2.4GHz)
Bluetooth: V4.0 (A2DP, AVRCP)
Dimensions: 3.14" x 4.42" x 0.70" (WxHxD)
Weight: 8.11 ounces (230 grams)
Firmware Upgrades: Over the air (OTA)
Body: Meteoric Titan color made from aircraft grade Duralumin
Price: $3499

Company Information
iriver House / Astell&Kern
902-5 Bangbae-Dong
Seocho-Gu
Seoul, Korea

Voice: +82-2-3019-1700
Fax+82-2-3019-1799
E-mail: webmaster@iriver.com
Website: www.iriver.com

Astell&Kern
39 Peters Canyon Rd.
Irvine, CA 92606

Voice: (949) 336-4540
Fax: (949) 336-4536
E-mail: support.inc@iriver.com
Website: www.AstellnKern.com