[time-nuts] Sound cards
J.D. Bakker
jdb at lartmaker.nl
Tue Jan 13 09:24:07 UTC 2009
>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.
JDB.
[using a custom board with a similar setup in a narrowband VNA]
--
LART. 250 MIPS under one Watt. Free hardware design files.
http://www.lartmaker.nl/
More information about the Time-nuts_lists.febo.com
mailing list