What is the UPGRADE location of the switch for? 31 March 2023 10:04 Updated See Chapter 4, point 12. ART of the manual of an AF amplifier bit. Related articles AF bit MANUALS How much power do you need? What is the RESCUE location of the switch for? I updated the firmware and now I can no longer connect via bit Drive software to the product? How many channels does your amplifier need to have?