Note: If you are referring to the Faudio FA4 IEM (which is a passive earphone), it does not have firmware. This guide assumes you own the Faudio FA4 Dongle DAC / Dongle Amplifier or the Faudio Project Y series that utilizes the FA4 chipset for DSP.
2.1 Device Architecture
The FAudio FA4 is a high-fidelity IEM featuring a hybrid driver configuration.
- Connectivity: MMCX (Micro-Miniature Coaxial) connector.
- Wired Mode: Passive transmission; no digital signal processing (DSP) or firmware involved.
- Wireless Mode: Dependent on the specific MMCX Bluetooth cable attached (e.g., FAudio BT cable or third-party modules like Shure RMCE-BT2).
Step 2: Put the FA4 into "Update Mode"
Unlike simple USB drives, the FA4 requires a specific key sequence to enter DFU (Device Firmware Update) mode.
Here is the standard method for most Faudio dongles:
- Disconnect the FA4 from your PC.
- Press and hold the "Play/Pause" button (or the volume up/down combo—check your manual). On many FA4 units, it is the middle button.
- While holding the button, plug the FA4 into your PC’s USB-A port (avoid USB hubs for this step).
- Release the button after 3-5 seconds.
- Check Device Manager (Windows). You should see a new device listed under "Universal Serial Bus devices" labeled "STM32 DFU" or "Faudio DFU". If you see "Unknown Device", reinstall the driver (see troubleshooting below).
Version 1.2.4 (Current Stable – Recommended)
- Fixed volume sync bug on iOS 17.
- Improved power efficiency (15% less battery drain from host device).
- Added UAC2 hardware volume (255 steps).
- Resolved static noise when charging phone while DAC is connected.
Recommendation: If you are using a faudio fa4 firmware upd from before 2024, upgrade to v1.2.4 immediately.
