Cirrus Logic CS4398 DAC: The Astell & Kern AK70 is equipped with a
Cirrus Logic CS4398 DAC (digital-to-analog converter) for 24-bit/192kHz
bit-to-bit playback, 32-bit to 24-bit downsampling, and DSD-to-PCM conversion.
- 32-Bit to 24-Bit Downsampling: The Astell & Kern AK70 offers
32-bit to 24-bit downsampling of music files. 32-bit/384kHz music files are
downsampled to 24-bit/192kHz, while 32-bit/352kHz music files are
downsampled to 24-bit/176kHz for playback.
- DSD-to-PCM Conversion: The Astell & Kern AK70 features DSD-to-PCM
conversion. It will convert DSD 64/128MHz music files to PCM 24-bit/176kHz
Media File Transfer: You can download digital music files from your
Windows PC or Mac computer to the Astell & Kern AK70 through its microUSB port
and the included microUSB-to-USB cable.
- Supported Audio Formats: The AK70 is capable of download and
playback of high resolution digital music files up to 24-bit/192kHz;
including FLAC, WAV, ALAC, and AIFF. It also supports playback of DSD
64/128MHz (DFF/DSF) music files by converting them to PCM (24-bit/176kHz).
In addition, the AK70 will support highly compressed music files such as
MP3, WMA, AAC, OGG, and APE.
- Computer Requirements: The AK70 is compatible with Windows 7, 8,
or 10 (32-bit or 64-bit versions of each). It also support Mac OS X 10.7 and
up. Mac users need to download and install the MTP program from the
Built-in Memory + External Storage: The AK70 has a built-in
64GB internal flash memory for downloading and store you digital music files.
You can also insert a microSD card (up to 128GB) in the memory card slot on the
side of the device for additional storage capacity. You microSD card should be
formatted in FAT32.
microUSB Port: The Astell & Kern AK70 is fitted with a
microUSB port that can be used as an input for or output. The microUSB port is
used for downloading music files from your computer and for charging the
battery. The microUSB port also supports USB Audio Out and allows you to use the
AK70 as a USB DAC for your Windows PC or computer.
USB Audio Out: The AK70 can be connected to the USB audio input of an
AV receiver or integrated amplifier using an OTG cable (sold separately). The
AK70 can output PCM music files to your receiver or amp. It can also transfer
DSD in native through DoP, or convert DSD into PCM for output to amplifiers that
do not support DoP.
USB DAC: The USB DAC functionality allows the AK70 to be recognized as
a sound card on a computer. The AK70 is connected to a free USB port on your
Windows PC or Mac computer; the music from your computer is then played through
the AK70's earphones port for an enhanced listening experience. This USB DAC
connection bypasses the inferior soundcard of your computer or laptop and uses
the AK70 as the USB DAC for better sound quality. It can support up to
24-bit/96kHz bit-to-bit music playback, providing much richer sound through
superior ambience and resolution way beyond the limits of the embedded soundcard
of your computer.
- Computer Requirements: Compatible with Windows PC and Mac
- Windows PC: XP (32/64-bit), 7 (32/64-bit), 8 (32/64-bit), and
- Mac OS: OS X 10.7 (Lion) or later
- Supported Music Files: Supported music files include MP3, WMA,
AAC, WAV, FLAC, ALAC, AIFF, DSD (DFF/DSF), OGG, and APE
- Sample Rate: 44.1 kHz to 96kHz
- Bit Rate: 16-bit or 24-bit
Notes: When using the AK70 as a USB DAC, its PEQ settings are not
applied, and output up to 24-bit/96kHz (not 192kHz) is supported. DSD 64/128MHz
is converted via DSD-to-PCM for playback.
Balanced & Unbalanced Output: The Astell & Kern AK70 is outfitted with
a 2.5mm balanced headphone output (L+/L-/R+/R-) and a 3.5mm unbalanced headphone
output (L+/R+/GND) for connection with a variety of headphones.
- 2.5mm Balanced Jack: The AK70 features a 2.5-mm/4-pole balanced output
(2.3 Vrms) for connection with compatible balanced earphones & headphones. This
type of connection requires that you connect your compatible headphones to
both the unbalanced port (ground) and balanced audio port (L/R) of the AK70. Unlike the unbalanced type, the balanced output type is capable of removing
noise (common mode noise) that can occur in "signal + inverting amplifier
signal" and has the strength of increasing output due to its double
- 3.5mm Unbalanced Jack: The AK70 also features a 3.5-mm/3-pole unbalanced output (2.3 Vrms)
that offers compatibility
with a variety of HiFi earphones and headphones. The 3.5mm headphone output can
also be used as a fixed line-level output, so you can connect the AK70 to
your home receiver, integrated amplifier, or powered speakers.
Built-In WiFi: The AK70 features built-in 2.4GHz WiFi
(802.11 b/g/n) which allows you to connect to your home's WiFi network
wirelessly with support for AK Connect & DLNA.
- AK Connect: The AK70 comes equipped with the AK Connect feature
that can be connected with network-ready Astell & Kern devices and speakers
(sold separately). It will wirelessly output its sound through Astell
& Kern speakers (sold separately).
- DLNA Compliant: It is also appointed with wireless networking DLNA (Ver.
1.0), which makes it easy to work with NAS/PC on the same network and
through an AK Connect app on your
Apple iOS 7.1+ or
Android OS 3.0 device. The AK70
can access and play back music files stored on a computer on the same
Note: Firmware/software updates are done over the AK70's WiFi network
Bluetooth Transmitter: The AK70 has built-in Bluetooth 4.0
for connecting a Bluetooth speaker, headphone, or receiver so you can listen to
your digital music files wirelessly. In addition to support for the standard
Bluetooth SBC codec, the AK70 offers support for aptX allowing CD quality
(16-bit/44.1kHz) wireless audio playback for Bluetooth speakers, headphones, and
receivers that also support aptX.
Note: DSD playback is not available via Bluetooth, and performance may be
limited for high-res playback; 48 kHz or lower resolution is recommended). Car
audio Bluetooth connections are not supported.
User Interface: The AK70 features a high-quality user
interface to make it easy to find and select your music files, change the
volume, and adjust the sound.
- 3.3" LCD Touchscreen: The full-color 3.3" LCD touchscreen
has a resolution of 480 x 800 pixels. The screen displays the title and
artist of the currently playing song, along with elapsed and remaining time,
with the album art in the background. On the touchscreen, you can touch the
Play/Pause, Previous/Rewind, or Next/Fast Forward icons to control playback.
You can make adjustments to the EQ, set the repeat and random modes, and add
the song to a playlist, all using the touchscreen interface.
- Rotary Volume Knob: The AK70 has a side-mounted
analog-style rotary volume knob. The volume control range is 00.0 to 75.0
with detents at every 0.5. As you adjust the volume, the volume range is
shown numerically on the display.
- Hardware Control Buttons: There are four physical
buttons on the unit: a top-mounted power button, along with side-mounted
Play/Pause, Previous/Rewind, and Next/Fast Forward buttons.
10-Band EQ: The AK70 has a 10-band Equalizer to tailor the
sound of your music to your preference. You can set the levels of each band from
-10dB to +10dB at 32kHz, 62Hz, 125Hz, 250Hz, 500Hz, 1kHz, 2kHz, 4kHz, 8kHz and
Gapless Playback: Gapless Playback allows you to play the
next song without any interruptions or silence. Gapless playback is only
supported between two audio files with identical bit rates, sample rates, and
Power Requirements: The AK70 is equipped with a rechargeable
Lithium-Polymer battery (2200mAh/3.7V). The battery charges via USB in about 8
hours using a USB port on your computer or about 4 hours using a USB/AC power
adapter (sold separately). A 39" micro-USB-to-USB cable is included to connect
the player to your charging device. A fully charged battery can provide up to
approximately 10 hours of continuous playback time.
Aluminum Construction: The Astell & Kern AK70 features an
aluminum construction. It measures only 2.375" (w) x 3.875" (h) x 0.5625" (d), and
weighs just 4.66 ounces. Clear plastic film protectors are included for the
front and back of the portable digital music player.
Optional CD-Ripper (Sold Separately): The AK70 can allow users to rip
CDs with ease by linking with the AK CD-RIPPER (sold separately). It supports
the CD track error correction feature and the meta data (ID3TAG) auto input
feature using Gracenote's database without any change. The
AK CD-RIPPER may not be properly recognized when using a power supply adapter
rated at less than 5V 2A.