Hi,

–AAX is for ProTools only. Samplitude uses VST format. For 64bit Samplitude you only need VST64. However, it is not a problem if you install all of the plugin formats.

–You do not need to change the plugin directory when you install the plugins. Leave the directory path as is.

–VST64 plugins go in C:Program FilesCommon FilesSteinbergVST2.

–Simply set  "VST Plugin Path" to be "C:Program FilesCommon FilesSteinbergVST2" in the Program Preferences, like I described above.

-Adrienne