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. 
128x128cheeg
Just like with anything, when you’re wondering about jitter... first get used to the sound of your system/gear as is. Then make a change and see if you hear any difference. If your DAC really does turn out to be "immune" to jitter... then changing USB cables (or whatever digital cable you’re using) should have no sonic impact. That’s an easy thing to test... just barrow a few alternate cables and swap. If you hear no difference at all, then that’s a coin in your "immune" jar. If you hear any difference at all, your DAC is not perfectly immune.

I’ll just say that I too had hoped that USB had finally found a way to defeat jitter by placing the master clock in the DAC and pulling packets etc. Well, at least with my DAC (Hegel HD30) USB cable swapping was clearly audible with a few cables I tried, and more dramatically, adding the PCT USBe in the path (between Aurender and DAC) has revolutionized the sound. A lot of marketing hype will throw out words like "immune" and perhaps your device is designed in such a way that it truly lives up to that claim. But even my Hegel DAC was supposed to be relatively unaffected by upstream jitter via USB given it’s design, and I’ve found that to be not the case at all.

p.s. I’m using the phrase "jitter" to broadly mean anything that allows the data to still arrive at the DAC uncorrupted, yet somehow the sound of D/A conversion is affected by other factors that are not digital in nature. Jitter (timing of the data) is most often discussed, but there are other non-digital variables as well such as noise. It’s entirely possible that what many of us hear and call "jitter" when changing cables and transports is really just changing the type of electrical/mechanical noise that gets sent along with the data to the DAC. Galvanic isolation is an example of a device that attempts to address this type of variable.
Benchmark DACs and a lot of others as well, "truly lives up to that claim", since the measured distortion and noise is well beyond what humans would hear. So if I use the word "immune" that's what I mean and if it is jitter a USB cable isn't going to fix it.
Wish I knew *exactly* what jitter sounded like. My system might be so full of jitter that it sounds like a garbage disposal to everyone but me, but how would I know? 
Best (and first) answer I found when researching “what does jitter sound like” came from John - 2009: 

“Like the sound of one hand clapping”.
Jitter creates sidebands to each frequency at very low level.  With a lot of frequencies (music) it is basically noise added to signal (inaudible without signal).  When I switched from CDP to Benchmark DAC1 I had impression of great clarity, that it took me a while to get used to.

The fact that sound changes with different cables might not have anything to do with jitter suppression since every connected cable injects electrical noise - some more, some less.