Where is the serial number on my Quartet? Chris May 10, 2021 18:39 Updated The serial number for Quartet can be found on the rear panel of the unit or on the box. Related articles Registration - Where do I Register & Download Software for my Apogee product? How do I Reset Quartet to the Factory Default settings? Where is the serial number on my ONE? My Avid Quartet isn't showing up in Maestro Is Duet 3 Compatible with my Apple Silicon M1 Mac? Comments 0 comments Article is closed for comments.