On Mac OS X, the Manager pane in the Plug-ins section of MASCHINE 2.0's Preferences contains an additional Use NI Audio Units checkbox.
Check this box to include the Audio Units (AU) versions of your Native Instruments plug-ins in the software’s plug-in menus and in the controller’s plug-in browser: If this checkbox is disabled (default setting), the AU versions of your Native Instruments plug-ins are still listed in the list above but they are disabled (checkbox unchecked). If you enable the Use NI Audio Units checkbox, all Native Instruments’ AU plug-ins will become available for loading in MASCHINE 2.0. In order to distinguish them from the VST versions, plug-in entries in the Native Instruments sub-menu of the plug-in menus and in the plug-in browser will display either (VST) or (AU) after their name:
Important Note: The Use NI Audio Units checkbox relates only to AU plug-ins from Native Instruments. AU plug-ins from third-party manufacturers are not affected by this setting. When the Use NI Audio Units checkbox is disabled or the AU version of a Native Instruments plug-in is disabled, you can still load Projects that use the AU plug-in.