open your studio one software and go to "preferences" and then click the "audio set up" tab. The top box allows you to choose from any audio interface you have plugged into the computer, and if you have the 44VSL plugged in and the computer recognizes it, you should see it in the drop down list that will be available. You can further define the device block size but the recommended setting is 256 samples at 44.1 khz