For music purists, those that own a massive music library, or anyone who wants to download hi-res audio files, the Astell & Kern AK Jr is a digital audio player meant to provide excellent sound reproduction and ample storage. A portable hi-fi audio player with a unique design, the Astell & Kern AK Jr offers support for multiple file formats, expandable storage, and external USB DAC functionality. I tested the Astell & Kern AK Jr alongside five other DAP and MP3 players to see how its design, features, and sound quality compare to other options on the market.
Design: Stylish…at first glance
The Astell & Kern AK Jr is 4.61 inches tall by 2.08 inches wide—close to the same dimensions as the original iPhone SE. The player I tested was rose gold, but it comes in other color options like silver. The body is aluminum with a glass backing, and it feels sturdy overall. At first glance, the AK Jr is attractive, but it has some odd design features that make it less functional and appealing. It has a 3.1-inch touchscreen, which only has WQVGA resolution (400 x 240). The screen also doesn’t cover the entire front face. There’s a large area of what appears to be wasted space underneath the screen, where there’s more than an inch of blank bezel space with no buttons or controls. The bezel also tapers, and it creates sharp corners that are almost pointy, enough that I scratched myself a few times pulling the AK Jr out of my pocket. Along the perimeter, there are dedicated buttons for track control and power and a microSD slot, but it’s not covered, so it’s unprotected from dust and dirt. The 3.5 mm headphone jack is on top of the unit, which I liked because it helps prevent cord tangling. There’s also a volume wheel, which is supposed to allow for one-handed operation, but I found the volume dial finicky and too loose, and it jumps up or down several volume levels when you scroll too fast. I would have preferred to just have physical volume keys.
Sound Quality: Excellent
Sound quality is where the Astell & Kern AK Jr thrives. Songs have depth and clarity, and music sounds outstanding. The AK Jr supports several file formats including FLAC, WAV, WMA, MP3, OGG, APE (normal, high, fast), AAC, ALAC, AIFF, DFF, and DSF. I downloaded a WAV version of Alanis Morrisette’s Jagged Little Pill. I hadn’t heard the album in a while, so this was the first time I’d heard it in this format, and I can’t begin to express just how great it sounded. Alanis’ vocals sounded less bright, and more pleasant and powerful. I even heard background instruments I hadn’t noticed before, as they came through clearly, but without overpowering the melody or vocals. I also listened to other tracks—Under the Bridge by the Chili Peppers, Lovely Day by Bill Withers, and more. I was impressed with the AK Jr’s sound quality and clarity. The AK Jr has a signal to noise ratio of 112 dB, and a frequency response of 20 hZ to 70 kHz. It has a low output impedance of only 2 ohms.
Features: An external USB DAC
Although the screen resolution isn’t all that great, the interface is clean and easy to navigate. It’s pretty basic, but I had no trouble finding and sorting through my music library. The Astell & Kern AK Jr has Bluetooth (version 4.0, A2DP/AVRCP), so you can connect wireless headphones or a wireless speaker. Unfortunately, there’s no Wi-Fi connectivity, so there are no streaming applications. The AK Jr can function as an external USB DAC (sound card) when you connect to a PC or Mac, however. The package comes with screen protectors for both the front and back of the music player, so you can protect the screen and glass backing. It doesn’t include headphones or a case, though.
Battery Life: Not great
The 1,450mAh Li-Polymer battery lasts up to 12 hours. During testing, the music player took approximately two and a half hours to reach a full charge (from roughly 75% drained). Once charged, the battery lasted for 8 hours and 15 minutes, alternating between Bluetooth and wired headphones, radio and hi-res music files.
Price: A reasonable drop
The Astell & Kern AK Jr sells for around $220, which is much less than its original retail price of $500 when it first hit the market a few years back. At $500, the AK Jr was overpriced, but the $220 price point is fair considering the build quality, sound, and features.
Astell & Kern AK Jr vs. Sony NWA45 Walkman
Among other features, the NWA45 also has NFC Bluetooth, support for LDAC (Sony’s codec), and a touch slider that lets you enable and disable the touchscreen. On the other hand, even though the Astell & Kern AK Jr has a few less than desirable design features (like the blank space at the bottom and pointy edges), the AK Jr. has a glass back, as well as the headphone jack ideally placed on the top of the music player instead of the bottom like the Sony Walkman. The Astell & Kern AK Jr. will be a desirable choice for enthusiasts and purists who want their music to sound accurate, but its form over function design and high price might be a turnoff for some people.
