A Symphony I/O MkII with a Pro Tools HD Option card installed requires no Apogee software to use it as an HD interface with Pro Tools HD. All of the Symphony’s parameters can be adjusted from the front-panel touchscreen and things like routing, sample-rate, and clock source are adjusted from Pro Tools HD software.

If you’re using the Symphony I/O MkII as a Thunderbolt interface, you will need to make sure the Symphony I/O MkII software is installed and the firmware is up to date.