Getting In Sync - E-Mu 1212M Owner's Manual

7 - Appendix

Getting in Sync

Getting in Sync
Whenever you connect external digital audio devices together, you need to be aware of
how they are synchronized to each other. Simply connecting digital out to digital in
doesn't guarantee that two digital devices are synced, even if audio is being passed.
Unless you have set one to be the Master and the other a Slave, they are probably NOT
synchronized and the quality of your audio will suffer.
S/PDIF and ADAT are two commonly used digital audio formats. Both these digital
formats carry an embedded word clock which can be used to synchronize the digital
equipment. You must enable "External Clock" on the slave device to have clock sync!
The diagrams below show two ways to synchronize an external A/D - D/A converter to
the E-MU Digital Audio System using the ADAT lightpipe connection.
In the first example, only the A/D converters on the external device are being used. Only
one lightpipe is needed as long as PatchMix is set to receive its word clock signal from
the external device. The external A/D is the Master and the E-MU DAS is the Slave.
External Device supplies Master Clock
EXTERNAL
The lightpipe carries eight
channels of audio data and
an embedded clock.
Master
Set PatchMix DSP to receive:
External ADAT Sync
Slave
PatchMix DSP supplies Master Clock
EXTERNAL
This lightpipe carries eight
channels of audio data.
Slave
This lightpipe carries an
embedded clock signal
& eight channels of audio.
Master
In the second example a second lightpipe is used to supply "embedded word clock", as
well as eight channels of audio to the external A/D - D/A. The external device MUST be
set to receive external clock via ADAT or the units will not be synchronized. The E-MU
Digital Audio System is the Master and the external A/D - D/A is the Slave.
124
(via ADAT)
ADAT Out
1 2 3 4 5
External A/D - D/A Converter
(via ADAT)
ADAT Out
1 2 3 4 5
ADAT In
External A/D - D/A Converter
6 7 8
Set External Device to receive:
External ADAT Sync
6 7 8
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