Many audio interfaces, A/D and D/A converters as well as other devices use the DB25 type connector to carry 8 channels of AES/EBU.  Typically the cables used “break out” to XLR connectors (4 male, 4 female) to accomidate individual stereo AES/EBU connections.

               
(AES/EBU DB25 port on Lynx Aurora16)       (Hosa AES/EBU breakout cable)

The trick is that there are two standard pin arrangements for DB25 AES/EBU connectors.  One is commonly known as the “Tascam pinout,” the other nicknamed the “Yamaha pinout.”   While they use the exact same DB25 connections, the 25 pins are used for completely separate channels.  If you connect two devices, one using the “Tascam” pinout the other using “Yamaha,” they simply won’t work together.

 
       (Tascam AES/EBU pinout)                                                    (Yamaha AES/EBU pinout)
Here’s a list of some manufacturers and the AES/EBU DB25 pinouts they use.  NOTE, this does not apply to analog DB25 connections.

Tascam

Avid/Digidesign
Universal Audio
RME

Yamaha

Apogee
Mackie
Lynx
SSL

Obviously this isn’t a comprehensive list.   If you’re not sure what pinout your device uses for AES/EBU DB25, check the manual for a pinout diagram and compare to the diagrams above.  If all else fails, feel free to ask us.