How to update the firmware for RETRO NANO:

https://www.fiio.com/newsinfo/998824.html

Updated at 2025-06-18

The following changes and improvements have been made to the V5.9:

1. Add power-saving shutdown function  

2. Optimize the noise issue when adjusting volume  

3. Optimize the issue of failed full charging with probability

4. Optimize the Bluetooth dual-device connection function

1.新增省电关机功能

2.优化加减音量有杂音问题

3.优化有概率无法充满电问题

4.优化蓝牙一拖二功能