How should I set up the ART/UPGRADE switch? 31 March 2023 14:12 Updated See Chapter 4, point 12. ART of the manual of an AF amplifier bit. Related articles 4. CONNECTION PANELS - DESCRIPTION 6. ACCORDO UPMIXER FOR BIT DRIVE 2.0 Why doesn't the amplifier turn on from SPEAKER IN input (high level)? How do I connect the B-CON to an AF bit?