J.D. Bakker skrev: >> Maybe I lost track and missed something, but I don't think I ever saw >> more on the subject of specific high-end sound cards that might be >> useful for nutty measurements. > > From an earlier list message: > >> [F]or best noise/jitter-performance an external ADC should be used, >> connected through a digital link to a PC sound card. One could do a >> lot worse than the TI PCM4222 eval board >> (http://focus.ti.com/docs/prod/folders/print/pcm4222.html), which >> accepts an external clock if so desired. At $149 (plus a tenner or >> two for the sound card) this will likely be much cheaper than an >> equivalent FireWire-device. > > The digital link in question is S/PDIF; with the current popularity > of Home Theater systems cheap cards with digital I/O have become > quite prevalent. As an added bonus, S/PDIF can be run over both > coaxial and optical media, the latter being attractive in further > isolating PC noise from any measurement setup. And of course, a > manufacturer's evaluation board is much better documented and more > suited to measurement-specific mods than a random sound card.
The optical link commonly being used for S/P-DIF is TosLink and it seems like it can be the cause of many problems. It seems like some care in doing the optical link setup is needed. I have never digged into why the optical links have that problem. I can only guess, but bad optical coupling seems reasonable. The multimode "fiber" seems to be leaving one or two things to ask for. Cheers, Magnus _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.