SPDIF can transmit a very accurate signal. The 0s and 1s are all usually quite correct. The problem is that jitter is small changes in duration of the 0s and 1s. Since the system uses serial data any clock variation from the source ripples through, although increasingly clever techniques are used to suppress most of these variations. The design approach was flawed in the definition of the interface, and not choosing a master clock to DAC and the source (disc drive or whatever).
TCP/IP is a mechanism where data is put into packages, with error detection, source and destination addresses, sequence numbers etc. This type of transmission uses data that is buffered, to build up the packages before sending, to receive packages then check on errors. In the SB3 / Boom there is several seconds of buffered audio data. In the good old days this type of buffer would be prohibitively expensive. CDs needed low cost players. The key issue overall is that the DAC can have a very low jitter clocking system, the audio data is requested in big packets when required, and locally converted to the serial data the DAC requires. Significantly greater accuracy in the timing of the 0s and 1s, but requires LAN technology, buffer handling, protocol processing etc. cheap today, unacceptable in 1982 (First CD CDP101 from Sony). Dave -- DaveWr ------------------------------------------------------------------------ DaveWr's Profile: http://forums.slimdevices.com/member.php?userid=9331 View this thread: http://forums.slimdevices.com/showthread.php?t=74341 _______________________________________________ discuss mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/discuss
