4
PCI-822 User’s Guide
— SPDIF cables —
The 15-pin PCI-822 breakout cable includes RCA (coax) connectors
for stereo SPDIF (Sony/Philips Digital Interface Format) digital audio.
Standard audio cables with RCA connectors have twisted-pair wire
rather than coaxial cable, and are not recommended for use with
SPDIF signals. Although they have the correct connector on each end,
and may work over short distances, they are not reliable for SPDIF
data streams. The reason is related to the differences between audio
and SPDIF signals — audio signals contain frequencies in the tens of
kiloHertz, but SPDIF signals contain frequencies in the tens of
megaHertz, much like a video signal.
Since SPDIF inputs and outputs look the same, make sure you check
the labels on the molded connectors of the PCI-822 breakout cable,
and connect your 75-ohm coax cables to the correct connectors.
— MIDI cables —
The 15-pin PCI-822 breakout cable also provides four DIN-5 MIDI
connectors for use with standard 5-pin MIDI cables. Since MIDI inputs
and outputs look the same, make sure you check the labels on the
molded connectors of the PCI-822 breakout cable and connect your
MIDI cables to the correct ports.
Note:
For reliable SPDIF connections, especially over distances
longer than a meter, use only 75-ohm coax video cables or cables
that are manufactured specifically for SPDIF use.
