[Warning]
Before firmware upgrade :
1. Make sure of your AK120’s battery level at least over 80%.
2. Make sure of your AK120’s memory size at least over 50 MB.
3. Don't remove the connection between PC & AK120 while transferring hex data.

[Newly added functions]
1. Supporting DSD format
   (1) Supported DSD spec
       1) DSD64 (1bit 2.8MHz), Stereo type
       2) DSDIFF(.dff), DSF(.dsf)
    (2) DSD can't be playback while using Blutooth function
    (3) High processing capacity of DSD playback can be result from acceleration of running battery down or processing speed's slowing down.

[Improvements]
1. Optical DAC
  (1) Power OFF , Sleep OFF function can't be activated during optical input2. BT function
  (2) playback music file via Blutooth can't be stopped inspite of removing its ear-jack.

[Bug Fix]
1. Playback issue for some of specific files was resolved.