Is Duet compatible with Mac OS X Yosemite (10.10)?

Duet FireWire, Duet 2 and Duet for iPad/Mac are all fully compatible with Mac OS X Yosemite (10.10 to 10.10.5).

See this guide for using Duet unit on current Mac OS versions

You can download and install the latest Yosemite compatible software package for your product from Apogee's downloads page under Legacy Product Installers. Download Apogee Drivers & Software