Originally posted by wissink I'm not sure I've ever heard of Power Sync honestly.
PowerSync is Cactus's term for HyperSync (a PocketWizard term).
It simply means that there is support for adjusting the flash timing so that you can use a regular flash pulse to light the whole frame (albeit with some level of gradation).
This only works for full power flashes, though, because at lower power levels, flash durations become too small.
Originally posted by wissink Oh my appologies, you mentioned the need for HSS flashes.
PowerSync does not need HSS-capable flashes as long as one is happy with the "full power" constraint.
So, yes you should be able to put a Yongnuo TX on top of a V6II and thus trigger multiple manual 560 IVs.