Music Friend In My Pocket

The AK70 supports the 2.5-mm 4-pole balanced output (2.3 Vrms) that has been in use since the second generation of the Astell&Kern players.

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 transmitting signals.

The AK70 can be used with a variety of balanced earphones and headphones made for Astell&Kern. It can also support the 3.5-mm 3-pole unbalanced output (2.3 Vrms), with compatibility with a variety of Hi-Fi earphones and headphones.

*This is an open-box item.

General Specifications

Model: AK70
Body Color: Misty Mint
Body Material: Aluminum
Display: 3.3inch WVGA (480 x 800) TFT LCD
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, Stereo / DSD128, Stereo
Output Level: Unbalance 2.3Vrms / Balance 2.3Vrms (Condition No Load)
DAC: Cirrus Logic CS4398 x1 (Single DAC)
Decoding: Support up to 24bit / 192kHz Bit to Bit Decoding
Input: USB Micro-B input (for charging & data transfer (PC & MAC)) / Connection Mode : MTP (Media Device)
Outputs: PHONES (3.5mm) / Balanced Out (2.5mm, only 4-pole supported)
Wi-Fi: 802.11 b/g/n (2.4GHz)
Bluetooth: V4.0 (A2DP, AVRCP, aptX)
Dimensions: 2.37 ”(60.3 mm) [W] x 3.81 ”(96.8 mm) [H] x 0.51 ”(13 mm) [D]
Weight: 4.66 oz (132 g)
Feature Enhancements: Firmware upgrades supported (OTA)

Audio Performance

Frequency Response: ±0.075dB (Condition: 20Hz~20kHz) Unbalance & Balance / ±0.56dB (Condition: 10Hz~70kHz) Unbalance / ±0.55dB (Condition: 10Hz~70kHz) Balance
Signal to Noise Ratio: 116dB @ 1kHz, Unbalance / 116dB @ 1kHz, Balance
Crosstalk: 130dB @ 1kHz, Unbalance / 130dB @ 1kHz, Balance
THD+N: 0.0008% @ 1kHz, Unbalance / 0.0007% @ 1kHz, Balance
IMD SMPTE: 0.0007% 800Hz 10kHz(4:1) Unbalance / 0.0006% 800Hz 10kHz(4:1) Balance
Output Impedance: Balanced out 2.5mm (1ohm) / PHONES 3.5mm (2ohm)

Clock source

Clock Jitter: 50ps(Typ)

Battery

Capacity: 2,200mAh 3.7V Li-Polymer Battery

Memory

Built-in Memory: 64GB [NAND]
External Memory: microSD (Max 128GB) x1

OS

Supported OS: Windows XP, Windows 7,8,10 (32/64bit), MAC OS X 10.7 and up