Need help with strange noise

[threepointwo]

I have been coming here for about a year now seeking various answers. What a great resource. Now I have a strange noise in my 1997 Boxster. I have a knocking noise that increases with speed when under power. It goes away when the clutch is pushed in. In reverse, it makes no noise under power but starts knocking when you push the clutch in.

I have replaced all of the CV joints so I can rule that out.

I have a short video on YouTube showing the symptoms. Any suggestions would be appreciated.

Porsche Boxter drivetrain noise - YouTube