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.)

Equipped with the Wolfson 8740 DAC

AK120 DAC & Amp Creates a Dual Mono System that separates Left & Right Audio Channels

From input to output, the design of the dual Wolfson WM8740 DAC implemented in the Astell&Kern AK120 independently separates the left and right audio channels, creating a true Dual-Mono audio output system.
When the analog audio signal passes through the dual Wolfson WM8740 DAC, not only does the AK120 use the Ultralow Distortion and Noise Technology, but executes the optimal digital noise reduction technology combined into the analog amp. The dual DAC built-in to the AK120 forms a dual-monaural audio ecosystem that brings wider soundstage, channel separation, and an overall richer sound.

24-bit/192kHz, SNR, THD+N → Hi-Fi Audio Spec

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.

Using the AK120 as an external DAC / USB DAC

Total memory

The AK120 is equipped with dual microSD card slots and supports up to 192GB of storage space.

The AK120 comes with 64GB of high-speed internal flash memory and dual microSD memory card slots capable of supporting up to 64GB of memory in each slot. Store up to 192GB of high-resolution audio with the AK120.

4 generations of MQS Albums supported on microSD cards

The additional memory card slot holds an important point.
24-bit album recordings will soon be released with music files stored in microSD memory cards.
For a mainstream album, LP (vinyl) records would be considered as first generation, second generations are cassette tapes, and Compact Discs (CDs) is the third and current generation.
Fourth generation albums are considered as MQS albums that are released in high capacity microSD memory cards. Comfortably enjoy two albums at once through the dual memory card slots of the Astell&Kern.


UI with an Integrated Touch Screen and Control Buttons

The AK120 offers very intuitive user experience through a more robust and sensitive touch screen.

The 2.4 inch touchscreen and the integrated hardware control buttons on the right and left side of the AK120 make setup quick and easy. Now with an updated and intuitive graphic user interface of the AK120, find your favorite tunes quickly even without taking it out of your pocket.
The curved design of the volume wheel guard provides additional protection to the volume wheel.

Combined Graphic User Interface(GUI) and Physical User Interface (PUI)

The updated GUI offers faster selection of your large library of music. Setting up the desired equalizer is also easy and is simple as a swipe of your fingers. The main GUI consists of six (6) key icons to help navigate and play your favorites quickly. Touching the upper part of the main menu instantly brings you back to the "Now Playing” screen. 
Access your current playlist in a flash by touching the left side of the "Now Playing” screen. Touching the "Option” icon brings up the other option settings, including the EQ settings. The dedicated GUI design give easy access of music makes the AK120 a true hi-resolution audio companion.

General Specifications

Model
AK120
Body Color
Black Only
Body Material
Aluminum
Display
2.4inch QVGA (320 x 240) IPS Touchscreen
Supported Audio Formats
WAV, AIFF, FLAC, ALAC, APE, MP3, AAC, WMA, OGG, DSD
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)
DAC
Wolfson WM8740 24-bit DAC (High-End Audio DAC) x2
Decoding
Supports up to 24-bit / 192kHz Bit to Bit Decoding
Charging Interface
Micro USB Type-B
Interface
USB 2.0, OPTICAL IN/OUT, Headphone Out
Dimensions
2.33 ”(59.2 mm) [W] x 3.50 ”(89 mm) [H] x 0.57 ”(14.4 mm) [D]
Weight
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)
Crosstalk
-128dB (1kHz 0dB, 24-bit 48kHz, No Load)
THD+N
0.0008% Typ (1kHz 0dB, 24-bit 48kHz, No Load)
IMD SMPTE
0.0005% (24-bit 48kHz, No Load) 800Hz 10kHz (4:1)
Output Impedance
3ohm

Clock source

Clock Jitter
50ps (Typ)

Battery

Capacity
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

Memory

Built-in Memory
64GB [NAND]
External Memory
microSD (Max 64GB) x2

OS

Supported OS
Windows XP, Windows Vista,7,8 (32/64bit), MAC OS X 10.6.5 and up