Before searching for a download, understand what YDT actually does. YDT is not a driver in the traditional sense (like USB Audio/MIDI drivers). It is a system software update utility.

After launching the new YDT, you will notice:

Downloading the software is useless without the correct hardware interface. Yamaha changed its diagnostic protocols around 2012–2013.

Assuming you have acquired the software package (typically an .ISO file or a zipped folder):

YDT is a universal tool, but the download link is often bundled with your specific console's firmware page. For example: