AES/EBU is a form of digital audio signal.
The 851N outputs this as a fixed, high-level output for connecting to professional audio equipment.
The volume cannot be attenuated from the 861N and must be controlled by the receiving equipment.
Some digital studio monitors and mixing desks can accept this form of connection.
The 851N AES/EBU terminals use an XLR connection but the type of cable used differs from standard audio cable.
It is recommended to use a high-quality cable specified for the AES/EBU digital audio signal.