Does removing "interface jitter" help, if my source has jitter?

I'm thinking of getting a Benchmark 3 DAC, and one of the selling features is its UltraLock3™ jitter attenuation system, which Benchmark says "fully isolates the inputs from INTERFACE jitter" (emphasis mine).   If my upstream source has jitter, will this system isolate that from the DAC?  My usual source is a Blusound Vault, and I suspect its jitter control is not as good as the Benchmark's. 
Having good jitter reduction and a good clock internally always helps. :)

Best of course is to use asynch USB so the clocks short and long term match up perfectly.

To be honest though, around 2010 or so DAC's jitter reduction seems to have improved remarkably. It's really hard to find a DAC that doesn't have absolutely excellent jitter rejection at any price.
Any jitter on S/Pdif will be suppressed.  It doesn't matter what introduced this jitter (CDP or digital cable).  The only jitter that cannot be removed is recorded jitter.  Early digital recordings were sometimes done with poor, jittery A/D clock.  Such jitter cannot be removed and the only way to fix it is to digitize again, if analog tapes are still available.
Any jitter on S/Pdif will be suppressed. It doesn’t matter what introduced this jitter (CDP or digital cable).

It’s unanimous! Almost unheard-of on Agon.
Little too quick on the trigger there sunshine

If this were correct there would be no difference to be heard (and there is I’ve heard it ) if a separate word clock cable was used to sync both transport and dac off the one "dac clock", instead of them using their own clocks.

Cheers George
The Benchmark DAC 3 distortion and noise level  is -140db no need to worry about jitter induced distortion.  This is true of competently engineered modern DACs. There are even a few R2R DACs that manage to keep distortion and noise below human audibly but I wouldn't waste money on them they're overpriced. The RME ADI 2 FS is very good DAC that's cheaper than the Benchmark.