Astell & Kern AK120 II


Brand Astell & Kern

What is the Portable MQS System?

Astell&Kern is the ultimate portable high-fidelity audio system capable of studio Mastering Quality Sound (MQS)

Mastering Quality Sound (MQS) is an acronym of collective lossless & high-resolution audio source formats, typically in 24-bit/44 to 192kHz of bit/sampling rates. Because MQS delivers about 6.5 times more detail than a conventional CD format (16bit/44.1kHz), listeners can enjoy a better and a more realistic sound quality.

24-bit/44 to 192kHz is the music industry norm used in the mastering process during sound production. However, the result of high resolution music files has to be compressed down to 16bit/44.1kHz so it can be stored into a single CD due to the memory storage shortcomings (~700MB). To produce the MP3 format, the high-resolution audio is compressed even further to 128 to 320kbps for the convenience of file size. These compressions remove the enormous amount of the details of the original recording because of memory storage limitations and listeners will never be able to hear the details.

Source frequency analysis comparison

frequencies up to 16kHz. However, WAV formats sampled in 48kHz can be reproduced up to 22kHz and higher. Frequency rates When comparing the frequency of each digital audio format, data loss is even more visible. MP3 formats can only reproduce of MQS files sampled in 44 to 192kHz can be reproduced even further than the WAV format.

DSD Playback support

High-Definition Digital Audio Formats and DSD Playback support with the AK120

DSD(Direct Stream Digital) is the digital audio format found embedded into SACD(Super Audio CD) physical media. 
In common digital audio recording, PCM(Pulse Code Modulation) is the Y-axis of a sine wave is divided into 65000 (16bit) to 1,670 million(24bit) and the X-axis is divided into 44,000(44.1kHz) to 192,000(192kHz) parts. When comparing a standard PCM digital recording to the DSD approach, the digital signal is transformed by Y-axis of the DSD sine waves that are measured at single bit(1bit, 0s and 1s) sequence and is divided 2.8 million(2.8MHz) to 5.6 million(5.6MHz) times into the X-axis. 
In general, when comparing SACD and PCM 16bit/44.1kHz Audio CDs, SACDs are recorded in frequency ranges up to 100kHz and greatly expand the dynamic range over 120dB while maintaining clarity of sound that a traditional PCM audio signal cannot reproduce. In order to listen to SACD, a dedicated SACD player is needed, but the AK120 brings SACD audio format playback to a portable player with DSD audio support. Enjoy the sound of DSD without a separate SACD player with the AK120. (AK120 supports the .dff and .dsf DSD formats up to 2.8MHz resolution.)

External DAC Support

Use the AK120 as an external DAC through the USB port.

With the Astell&Kern AK120, the Wolfson WM8740 chips can also be used as an external DAC through the USB terminal.
Enjoy more lively sound from the music files stored through a variety of sources, including computers and car audio systems.
The optical IN port of the AK120 can also be used as an external DAC.


General Specifications
Body Color
Black Only
Body Material
2.4inch QVGA (320 x 240) IPS Touchscreen
Supported Audio Formats
Sample rate
WAV, AIFF, FLAC, ALAC : 8kHz ~ 192kHz (8/16/24-bits per sample)
Output Level
L: 1.5Vrms + R: 1.5Vrms (Condition No Load)
Wolfson WM8740 24-bit DAC (High-End Audio DAC) x2
Supports up to 24-bit / 192kHz Bit to Bit Decoding
Charging Interface
Micro USB Type-B
USB 2.0, OPTICAL IN/OUT, Headphone Out
2.33 ”(59.2 mm) [W] x 3.50 ”(89 mm) [H] x 0.57 ”(14.4 mm) [D]
5 oz (143 g)
Feature Enhancements
Firmware upgrades supported
Audio Performance
Frequency Response
±0.02dB (Condition: 20Hz~20kHz) / ±0.2dB (Condition: 10Hz~70kHz)
Signal to Noise Ratio
113dB (1kHz 0dB, 24-bit 48kHz, No Load)
-128dB (1kHz 0dB, 24-bit 48kHz, No Load)
0.0008% Typ (1kHz 0dB, 24-bit 48kHz, No Load)
0.0005% (24-bit 48kHz, No Load) 800Hz 10kHz (4:1)
Output Impedance
Clock source
Clock Jitter
50ps (Typ)
2,350mAh 3.7V Li-Polymer Battery
Continuous Playback Time
Up to 14 hours (Standard - MUSIC: FLAC, 16-bit, 44kHz, Volume 37, EQ Off, LCD Off)
Charge Time
About 6.5 hours
Built-in Memory
External Memory
microSD (Max 64GB) x2
Supported OS
Windows XP, Windows Vista,7,8 (32/64bit), MAC OS X 10.6.5 and up
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