Re: [LAU] [OT reply to recived OT ; )] RME analog out of phase to ADAT connected Behringer analog out

On Tue, Jun 14, 2011 at 10:03 AM, Ralf Mardorf <ralf.mardorf(a)alice-dsl.net> wrote: you're really deeply confused. let me try to illustrate (the diagram is somewhat simplified to try to make the point more clear. the actual reality is a bit more complex in terms of where the clock is actually used, and so on). the section marked "buffer" refers, typically, to some RAM into which a relatively large (say, 32 or more) samples can be stored "in front of" the D/A converter. digital samples-> buffer-> D/A converter digital-side>internal buffer->D/A converter analog side ^ | | sample clock the sample lock says "get another sample", so the device will fetch another sample at precisely the same time (to within a picosecond or so) of other devices using the same clock (if any). this is important. but ... the way each D/A converter circuit works is independent once it has the next sample value available. the amount of buffering inside the D/A converter is variable from converter to converter, as is the actual conversion process itself. So lets put 2 of them together: digital samples-> buffer-> D/A converter digital-side>internal buffer->D/A converter analog side ^ | | shared sample clock | | v digital samples-> buffer-> D/A converter digital-side>internal buffer->D/A converter analog side it makes no different whether the sample clock is delivered from an internal clock crystal, the ADAT cable, word clock via BNC or any other method. once the samples are delivered to each D/A converter, there is no "sync" anymore. this has nothing to with RME, and everything to do with the basics of digital audio and digital-to-analog convertion.