11
Word Clock and external clocking
The "heartbeat" of digital audio gear is determined by an electronic
clock. Due to design and manufacturing tolerances, the internal
clocks within different pieces of digital audio gear will vary by small
percentages.
To provide flawless data exchange and to prevent timing drift
between tracks, it's necessary that the digital audio gear share the
same clock. In other words, a piece of equipment is designated as the
"master"
and it uses its own
internal clock
. The other pieces of gear
are then set to be the
"slave(s)",
using an
external clock.
When a SPDIF or ADAT option card is added to a WavePRO interface,
the interface is enhanced to support external clocking.
The clock can be transmitted between the gear by the digital audio
interface cable (SPDIF or ADAT). In other words, the clock is
embedded in the digital audio signal.
Additionally, a Word Clock feature is included with the WavePro ADAT
option card. Word Clock is shared between digital audio gear via a
coaxial cable connected to the Word Clock input and output BNC
jacks.
NOTE:
When you are using a WavePRO interface to receive
(record) digital audio data from another piece of
gear, it's necessary that the WavePRO interface be set
to use
external clocking.
The WavePRO card will act
as a
"slave"
to the other digital audio equipment.
TIPS
n
If you receive an "invalid sample rate" error message, check the
connections between the WavePRO interface and the audio
equipment. Also, make sure the sample rates all match up.
n
If you experience audio drop-outs and you are using the RCA jacks
for SPDIF, make sure that the cable you're using is 75-ohm cable
(video quality) and *not* standard audio cable that's used in home
stereos.
