On 22-11-07 11:10, Clemens Ladisch wrote: > Paolo Saggese wrote: >> Of course I plan to use the PC only to provide a "bitperfect" >> (exact copy of the original media, normally CD) digital stream >> to an external DAC. >> >> As you probably know better than me, the one major known problem >> when you strive for the highest possible quality in digital audio >> reproduction is jitter... and the best (if not only) way to really >> minimize it is to use a good, clean and stable clock close to the >> DAC chip, slaving everything else to that one. >> >> Thus, what I would need to do would be to "slave" the sound card >> SPDIF output clock to the external DAC clock i.e. to make this one >> become the "master clock" for the whole digital audio stream. > > An SPDIF input _always_ derives its clock from its signal. > > Besides, the clock for the actual DAC has to be a multiple of the bit > clock anyway, so there must be a PLL to derive the DAC's clock from the > input signual, i.e., the amount of DAC clock jitter depends more on the > PLL implementation than on the input signal quality. I don't quite understand your reply. He isn't asking to sync the S/PDIF in to the signal, he's asking to sync the S/PDIFF _out_ to the S/PDIF in. Ie, to have a dummy S/PDIF connection DAC --> Card S/PDIF In that exists only to supply a clock to the card, to which Card S/PDIF Out --> DAC will then be synced. This is a valid wish, isn't it? And at least the M-Audio Audiphile cards can sync themselves to the S/PDIF In clock. Rene. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
