The guide explains how to use the AK Jr portable audio player, covering components, power management, connections, firmware upgrades, USB‑DAC, Bluetooth…
The Astell&Kern AK Jr is a compact high‑resolution portable audio player with a 3.1‑inch touch screen, Wolfson DAC and support for a wide range of audio formats. This manual provides step‑by‑step instructions for basic operation, file management, and using the device as a USB DAC or Bluetooth audio source.
Key topics include power‑supply management, charging recommendations, firmware upgrade procedures, Bluetooth pairing, safety cautions, and a detailed troubleshooting section. Technical specifications such as display resolution, battery capacity, dimensions, supported operating systems and audio capabilities are listed at the end of the guide.
| Display | 3.1‑inch WQVGA (240×400) Touch Screen |
|---|---|
| DAC | Wolfson WM8740 (single DAC) |
| Battery | 1450 mAh 3.7 V Li‑Polymer |
| Weight | 3.45 oz (98 g) |
| Supported audio formats | WAV, FLAC, WMA, MP3, OGG, APE, AAC, ALAC, AIFF, DFF, DSF |
| Supported operating systems | Windows XP‑8 (32/64‑bit), macOS 10.7.5+ |
| MicroSD capacity | Up to 64 GB |
Using a 5 V 2 A adapter while the device is turned off, a full charge takes up to four hours.
The player supports A2DP and HID (the HID profile works only with iriver’s IAA01 model).