When native UAD (UADx) plug-ins are installed, they are copied to the following default locations:
Windows
VST3 (64-bit)
C:\Program Files\Common Files\VST3
AAX64
C:\Program Files\Common Files\Avid\Audio\Plug-Ins\
Mac
VST3
Macintosh HD/Library/Audio/Plug-ins/VST3
Audio Units
Macintosh HD/Library/Audio/Plug-Ins/Components
AAX 64
Macintosh HD/Library/Application Support/Avid/Audio/Plug-Ins
Note: For default install locations for UAD-2 plug-ins, click here.