Page 12 of the Manual:

FACTORY RESET
Performing a factory reset will return CODE’s Presets back to when it was new.
To perform a factory reset:
• Power OFF the amplifier using the ON/OFF switch (#13 in this manual).
• Whilst holding down the AMP Section Switch, turn the power ON.
• The screen will display a notification that the amplifier is about to be returned to its
factory settings.
• If you are sure that you want to perform a factory reset, press and hold the EXIT/STORE
switch to confirm.
• If you do not want to restore the factory presets, pressing any other switch will cancel
the factory reset operation and boot the amplifier as normal.