Originally Posted by edorr
No, they both run at native sample rate. The MSB has a 0.5s delay because of all the processing in the reclocking circuitry and uses a $5k optional femto clock, so I doubt they are cutting any corners.
No two devices can run at EXACTLY the same frequency independently. Impossible in this known universe.
To avoid any bit loss the two clocks must be synchronized. Could be via a slow rate PLL, but they must be locked. No two oscillators are identical. Even two Rubidium standards will drift apart. Case in point: Before there were video frame synchronizers available in the late 1970s, the TV networks often would have two Rubidium standards calibrated together, one in the truck calibrated against the unit at the NOC. By the end of a typical live sporting event they would be out of phase enough to cause color shifts at cuts. That's about 2 degrees at 3.58mhz. And gen-locking the network to a remote truck is out off the question for reliability reasons.
So clocks must be at least loosely locked or you will have a buffer under / overflow. No audiophile company can get around this. It's basic laws of physics and time.
And I'm not impressed with the $5K Femto clock. A good used Rubidium standard was about $10K in the 1990s and there's no way the "Femto clock" is even close to half that accuracy. I have worked with Rubidium standards over the years and even these will not magically sync a CD transport to a DAC for very long. Remember that 48/96khz audio is roughly the same bandwidth as NTSC analog video.
IME, the name of the game today in most entertainment grade digital audio systems, that includes pro broadcast stuff too, is sample rate conversion. It's much easier thanks to modern silicon fab than dealing with clock lock problems and the side effects are negligible.
EDIT: I read the blurb at MSB. Seems they are buffering the audio in a 500ms memory. But what they don't tell you is that memory will under or overflow at some point resulting in a soft click which they may in fact mute out as they can "see it coming". But it will always be audible but probably not noticed.
This is basic (and crude) sample rate conversion - deep buffer memory.Edited by Glimmie - 11/5/13 at 4:54pm