To install firmware on your MixAmp Pro please go to the website below:
www.astrogaming.com/firmware
Download the most recent version of MixAmp Pro firmware.
Once downloaded, plug in the MixAmp Pro to your computer via the USB. The optical connection is not required.
Now that you are hooked up to the PC, run and complete the firmware installation. Once started the firmware will guide you through the process.
Be sure to follow @ASTROGaming and @ASTROSupport for more updates on new firmware and features.