Updated at 2024-12-30

BTR15 Bluetooth V4.4 firmware firmware download link: Click here

How to update the Bluetooth firmware: Click here

BTR15 Bluetooth V4.4 firmware firmware upgrade content:

1. Fixed the issue where some phones would freeze when connecting via Bluetooth.

2. Fixed the issue where there was a probability of no charging when USB was quickly plugged and unplugged.

3. Optimized the charging logic.

1.修复蓝牙连接部分手机会死机的问题

2. 修复usb快速拔插有概率不充电的问题

3.优化充电逻辑

BTR15 Bluetooth V3.8 firmware firmware upgrade content:

Updated at 2024-06-17

1. Fixed the issue where the gain level changes from low to high after rebooting.

2. Fixed the issue where USB 1.0 mode changes to USB 2.0 after rebooting.

3. Fixed the issue where the device would automatically turn on after a factory reset.

BTR15 Bluetooth V3.8 firmware download link and update instruction: Click here

BTR15 Bluetooth V3.5 firmware and XMOS V125 firmware upgrade content:

Updated at 2024-02-28

1. Added Power on/off prompt tone.

2. Added Bypass mode under EQ.

3. Fixed the issue where the battery icon kept scrolling after beeing fully

    charged.

4. Fixed the issue where the battery icon is always full after enablirng

    charging protection.

5. Fixed the issue where the device would automatically turn off if

    unplugging/plugging USB after upgrading the firmware.

6. Fixed the issue of EQ custom adjustments on FIIO Control.

7. Fixed UI display bugs.

8. Modified EQ switching logic: MQA is supported when EQ is OFF; while MQA

    and DSD tracks are not supported when EQ is ON.

BTR15 Bluetooth V3.5 firmware and XMOS V125 download link and update instruction: Click here

BTR15 Bluetooth V2.2 firmware content:

1. Added the function of modifying the EQ custom name in Fiio Control App;

2. Added screen off time option, which can be set in the menu;

3. Added PC/BT/PHONE, the three modes have independent volumes;

4. Fixed the issue where switching high and low gain multiple times would cause the gain to

    be inconsistent;

5. Fixed the problem that the charging icon would flash when charging is switched from

    PHONE mode to PC mode;

6. Fixed the problem of full charging and inaccurate battery display;

7. Optimize the battery life issue when using UAC in PHONE mode.

8. Optimize other performance.

BTR15 Bluetooth V2.2 firmware download link and update instruction: Click here

BTR15 XMOS V121 firmware content:

1. Update PID.

BTR15 XMOS V121 firmware download link and update instruction: Click here