| That said, using the 'lead' converter's internal clock will likely provide the best quality for that converter.
Why?
Some folks seem to think that supplying a supposedly superior external clock will help a converter that has a supposedly inferior internal clocking implementation.
Unfortunately, this thinking seems often based on the false notion that the external clock replaces the internal clock's operations. But the internal clock in a conventional converter is always the direct soruce of timing for internal operations. If external clock is supplied, it actually makes the internal clock circuitry work harder at a more difficult job -- synchronizing its own internal timing to the incoming clock signal.
Because of that, the slaved clock circuitry is always trying to correct itself to the incoming clock -- and that almost invariably tends to produce more jitter.
What about those who claim that simply hooking a Big Ben or similar external clock to a single stand alone converter seems to improve the apparent quality?
People as divergent as converter design legend Dan Lavry and engineers at Digidesign have suggested -- perhaps somewhat sardonically -- that some people would appear to simply prefer the sound of extra jitter.
At any rate, malditoyanki is correct -- any time you have two converters yoked together via direct digital audio connection (say, via ADAT-lightpipe, AES-EBU or S/PDIF), the converters must be synchronized or they will drift apart due to tiny differences between the crystals that lie at the heart of all conventional converter clock circuits.
You can desginate one converter (typically the 'best') as the master or you can rely on an external standalone clock source like the Big Ben, Timepiece, etc.
And, for complex rigs, a standalone clock with multiple connection options may well be more convenient and easier to work with, even if it increases jitter in the converter you might otherwise have designated master. |