The Symphony I/O Mk II PTHD Card expands a Symphony chassis with the respective functions.
The Symphony I/O Mk II has one slot for a Thunderbolt card and one slot for an expansion card. A Symphony I/O Mk II can be configured and operated with either a Thunderbolt card or an expansion card, or with both.
The Pro Tools HD expansion card allows Symphony I/O Mk II to connect directly to HDX and HD Native cards in a Pro Tools HD system.

• Primary port: Mini PC32 port (also known as Mini DigiLink) for connecting to compatible Pro Tools HD cards.
• Aux: USB port for importing firmware updates.
• Loop In / Out: Ports for synchronization with other Pro Tools HD interfaces.