allowed and cause malfunction.
8. Wordclock synchronization
8.1. General
In digital audio systems it is required that all devices (mixers, converters, effects etc.) work with a
common clock (the so-called "wordclock"). This ensures that signal is processed on all channels in all
devices at the same time. Without a common clock, local clocks drift apart with time, which may
cause disturbances like clicks, pops and dropouts.
ADAT Multicore Extender does
not
require a wordclock signal,
but transmits the wordclock signal which is contained in the ADAT data stream.
8.2. Wordclock synchronization over ADAT
The wordclock signal is generated by a master device (mostly the mixer) and is output along with the
audio data over the ADAT interface. Devices receiving the signal reconstruct the wordclock from the
data stream.
When using ADAT synchronzation, there is no need for additional sync cables.
Use the "Local Loopback" function (see 7.1. Input/output mode (DIP switches 1-4)) to have
additional ADAT sources for synchronization purposes. Look at the example in 9.2. Digital
24/8 multicore (sync over ADAT).
8.3. Wordclock synchronization over separate coax cable
This configuration is often used in larger installations where simple ADAT sync is not sufficient.
The sync signal generated by the master (mostly the mixer) is distributed over a separate cable to all
devices involved. Commonly used is 75 ohms coaxial cable with BNC plugs, with 75 ohms
termination resistors at each end.
If you want to use this kind of sync distribution, you have to lay an extra coaxial cable beside the Cat5
cables (see 9.3. Digital 48/16 multicore (sync over separate coax cable)).
9
