1 – Introduction—Word clock issues
TASCAM DM-24 Reference Manual
11
Word clock issues
The “word clock” in a digital audio system is the tim-
ing information that enables the digital audio sam-
ples in a system to be synchronized between the
different devices. It is completely unconnected with
timecode clocks, etc.
There must be one, and only one, word clock master
device in a digital audio system. The DM-24 is capa-
ble of acting as a word clock master or as a slave.
WARNING
There should be one, and only one, word clock master
in a setup. Multiple word clocks in a setup may result in
noise. which can damage monitoring equipment
(speakers and amplifiers).
Check with the other equipment that you are using to
see whether it can be a master or slave, and work out
which device will be your word clock master. If the
DM-24 is to be a word clock slave in your system, it
can accept word clocks from the following sources:
• An external clock connected through the dedicated
connector
• The TDIF-1 interfaces
• The integral ADAT interface
• Either of the two
DIGITAL IN
interfaces
• Either of the slots occupied by an optional digital
interface card. In the case of an AES/EBU interface
card, any of the four stereo signal pairs may be
individually selectable as the word clock source.
• If two DM-24 units are being cascaded, the clock
source on a cascaded DM-24 will always be the
cascade master DM-24 unit. The master of the cas-
cade chain can select its clock from any available
source.
The clock can be at 44.1 kHz or 48 kHz or 88.1kHz
or 96kHz with some variation possible for varispeed,
etc. at ±6%.
NOTE
When the DM-24 is linked to an external word clock, it
can only use a base frequency clock. Even when many
external devices are operating at high sampling fre-
quencies, they output such a base frequency clock. If
the external device does not do so, and only outputs a
high sampling frequency clock, the DM-24 must be used
as the word clock master for the system.
