I believe you are referring to audio going to the inputs.
Without VSL software installed, your Audio Interface will be managed through Audio MIDI Setup.
You need to open up Audio MIDI Setup and set the 44VSL as your default input device.
Audio MIDI Setup
On the Toolbar, select Go, then Utilities.
Then double click 'Audio MIDI Setup' to launch it.
Your AudioBox (VSL) should now appear in the list of devices on the left column.
However, it is not set as the default Input (Recording) and Output (Playback) device.
At the bottom of the screen click on the cog wheel with a down arrow and select to "Use this device for sound input"
Then again, At the bottom of the screen click on the cog wheel with a down arrow and select to "Use this device for sound output"
Now your AudioBox (VSL) is setup correctly.
You can now exit Audio MIDI Setup and Close the Utilities folder.
System Preferences - Sound
We can also go to System Preferences to check that it’s showing up correctly.
lick on the Apple in the Finder Toolbar and select ‘System Preferences’
In System Preferences click on ‘Sound’
This is where you should see your AudioBox Series device appear for Output and Input.
Your AudioBox is now setup.
The AudioBox VSL software will not be functional on OS X past 10.10.
Continue to use your AudioBox VSL interface as a class compliant device.
You can find more tutorials on how to route your audio in your OS and in your applications in our knowledge base at http://support.presonus.com/forums/20568836-AudioBox-VSL-Series
Source: http://support.presonus.com/entries/20353062-How-do-I-completely-remove-AudioBox-VSL-on-my-Mac-
