Can I run YouTube on my TV and output the sync audio through Roon?

[Carl]

Unfortunately no, as Roon only supports audio output, not audio input.
There is some discussion on this in this topic:

Roon as an output channel for other sources? Ugh, but maybe

@Danny What do you think of this crazy idea? So a friend emailed me some recordings, comparing his new upright bass with the old one. I wanted to listen through my quality headphones or the big speakers, so I started thinking of how I could feed that sound into Roon. I could RDP into the Windows NUC that runs Roon, and select the Meridian USB driver as the system output and start the mail program and play the audio – stupid idea in this particular case, I just saved the MP3 files onto disk on a…