If it helps my TOB recently went and I got it replaced. For me it was a very different sound. Not saying it for sure couldnt be the TOB. To me sounds like something is loose. For my sound it occurred more loud when I pressed in the clutch which is more typical of the TOB going. I took videos of my sound which was a TOB issue and it sounds quite different than yours.
Listen for yourself:
http://www.ft86club.com/forums/showthread.php?t=121318