Astell&Kern AK Jr

Our Price: £399.00

In Stock

Free UK delivery

The Starting Point of Music, AK Jr.

WHAT HiFi Awards 2015 Portable music players - Product of the year

Built around the same Wolfson WM8740 DAC chip as the original AK100/AK120 and housed in a sleek new aluminium body with an upgraded output stage, more responsive OS and a lower price point we think Astell&Kern are on to a winner here!

Thin and Light

The AK Jr project gives everyone the opportunity to comfortably listen to high resolution audio, anytime and anywhere.

Although the Astell&Kern was a portable device, its relatively large size made it less convenient for some. The AK Jr’s compact design delivers the highest sound quality while fitting comfortably in your pocket.

The AK Jr is like carrying a small concert in your pocket.

Design Story

The AK Jr simplifies complex features of Hi-Fi audio to a smartphone-like experience. The simplified design exemplifies the original concept of the AK Jr. The raised screen provides secure grip and slims down the profile from 8.9mm to 6.9mm. The full aluminium body and textured aluminium volume wheel allows smooth one-handed operation.

Increased output and lowered impedance

The AK Jr's output level of 1.95 VRMS represents a 14% increase over the AK100's 1.5 VRMS. Our engineers have reduced the output impedance to 2 Ohms for a significant gain in sound fidelity from the original AK100's 22 Ohms.

As the AK Jr supports many various types of earphones and headphones, a separate amplifier is unnecessary.


The AK Jr supports DSD, the digital audio format widely considered to be the next-generation in high resolution audio. Listen to a greater range of audio through DSD.

- The AK Jr converts 2.8 MHz DSD files to PCM.


The AK Jr can also function as an external DAC (sound card) when connected to a PC or Mac via USB.

When playing music stored on a computer, the AK Jr delivers the same high level of audio quality while eliminating the need for a built-in sound card.

- The AK Jr's EQ settings are disabled when used as a USB DAC. The USB DAC feature also supports UAC 1.0 (USB Audio Class 1.0 / 24-bit, 96 kHz) audio output.

Full Touch Screen

The AK Jr features a 3.1" LCD touchscreen that is about 1.4 times larger than the AK100’s LCD. The smartphone-like full touch capabilities offer responsive interface and the larger screen displays more information.

Album covers that are in a 4:3 format on the AK100 are now displayed 1:1 aspect on the AK Jr’s larger screen.

The AK Jr features 64GB of memory to store more music than ever before. Supporting microSD cards up to 64 GB, the AK Jr is capable of offering a whopping total storage capacity of 128 GB!

The combined 128GB of internal memory and external microSD card capacity is capable of holding more than 1,250 high resolution audio. (Based on one, 4-minute song @ 24 bit/96 kHz, taking up 90MB)

General Specifications

  • Body colour: Sleek Silver
  • Body material: aluminium
  • Display: 3.1inch WQVGA (240 x 400) touchscreen
  • Supported audio formats: WAV, FLAC, WMA, MP3, OGG, APE (Normal, High, Fast), AAC, ALAC, AIFF, DFF, DSF
  • Sample rate: FLAC, WAV, ALAC, AIFF : 8kHz ~ 192kHz (8/16/24bits per Sample)
    / DSD : DSD64 (1bit 2.8MHz), Stereo (DSD to PCM)
  • Output level: 1.95Vrms
  • DAC: Wolfson WM8740 x1 (Single DAC)
  • Decoding: supports up to 24bit/192kHz bit-to-bit decoding
  • Input: USB Micro-B input for charging & data transfer (PC & MAC)
    / Connection Mode : UMS (USB Mass Storage)
  • Outputs: PHONES (3.5mm)
  • Bluetooth: v4.0
  • Dimensions: 2.08" (52.9mm) [W] x 4.60" (117mm) [H] x 0.35" (8.9mm) [D]
  • Weight: 3.28oz (93g)
  • Feature enhancements: firmware upgrades supported (F/W file copy)

Audio Performance

  • Frequency Response: ±0.04dB (Condition: 20Hz~20kHz) / ±0.3dB (Condition: 20Hz~70kHz)
  • Signal to Noise Ratio: 112dB @ 1kHz
  • Crosstalk: 120dB @ 1kHz
  • THD+N: 0.005% @ 1kHz
  • IMD SMPTE: 0.0006% 800Hz 10kHz(4:1)
  • Output Impedance: 2ohm

Clock source

  • Clock Jitter: 50ps (Typ)


  • Capacity: 1,450mAh 3.7V Li-Polymer battery


  • Built-in Memory: 64GB [NAND]
  • External Memory: microSD (Max 64GB) x1


  • Supported OS: Windows XP, 7, 8 (32/64bit), MAC OS X 10.7 and up

More products from Astell&Kern


PDF Astell&Kern AK Jr User Guide (2.5 MB)

Firmware Astell&Kern AK Jr Firmware v1.03 (37.7 MB)


Before firmware upgrading:

  1. Make sure of your AK Jr's battery level at least over 50%.
  2. Make sure of your AK Jr's memory size at least over 50 MB.
  3. Don't remove the connection between PC & AK Jr while transferring hex data.

[How to upgrade]

This model doesn't support OTA - customers have to download Hex file themselves.

  1. Connect the AK JR to PC.
  2. Copy the AK_JR.hex to the root folder of the of AK JR.'s internal memory.
  3. Disconnect the AK JR safely, and then Firmware upgrade will be started.

[Newly added or revised functions]

  1. Operation Stabilization


Press Reviews

What Hi-Fi? Sound and Vision's '5 Stars' award

, September 2015 5 / 5.

Hi-Fi Choice's '4.5 Stars' awardHi-Fi Choice's 'Recommended' award

, August 2015

Outstanding build and performance in a neat, compact and affordable unit. 4.5 / 5.

, July 2015

Big, beautiful sound within such a small package that I never felt was possible. Bravo Astell&Kern, you've got another winner on your hands!

, July 2015

As for its sound quality... it was first-rate... clarity coupled with impressive dynamic contrast... Bass definition is superior... the AK Jr sounded powerful, open and clear.

Digital Trends's '4½ Stars' award

, July 2015

...the frontrunner for those looking for audiophile sound they can slip into their pocket. 4.5 / 5.

, June 2015

If you’ve already dropped cash on a nice pair of headphones and are contemplating “What’s next?” the Astell&Kern AK Jr. will bring them to life at home, on public transport and at work.

, June 2015

Junior by name, but very grown-up by nature, the precocious child of the Astell & Kern family is perhaps its most impressive offering to date...

Customer Reviews

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