NTP Technology Penta 721s Modular Audio Router and InterfacePenta 721s is a modular MADI, AES and DANTE router with one slot for an optional expansion card, which provides a versatile and flexible solution for signal distribution and audio routing via AES EBU, MADI, as well as routing via IP Gigabit Ethernet and optical fibre networks. The expansion slot can be installed with any of the available Penta expansion cards. Penta 721s is a compact 1U digital audio interface that comes with eight AES EBU input