Creative 0404 owner manual Getting in Sync, External Device supplies Master Clock

6 - 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 is probably the most common digital audio format. S/PDIF carries 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 converter to the E-MU Digital Audio System using the S/PDIF connection.

In the first example, the external A/D converter is the master clock for the system. Only one S/PDIF cable is needed (either optical or coaxial) 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.

PatchMix DSP

External Device supplies Master Clock

S/PDIF	(via S/PDIF)
(Optical)
In	The S/PDIF cable carries two
	channels of audio data and
Out	an embedded clock.

or

S/PDIF Out

In
Out	Master
S/PDIF	External A-D Converter
(Coax)
Slave

Set PatchMix DSP to receive:

External S/PDIF Sync

PatchMix DSP

S/PDIF

PatchMix DSP supplies Master Clock

(via S/PDIF)

(Optical)	This S/PDIF cable carries two
In	channels of audio data.
			Set External Device to receive:
Out
		S/PDIF Out	External S/PDIF Sync
or
In	Slave
Out	S/PDIF In	External A-D Converter
S/PDIF
(Coax)

Master	This S/PDIF cable carries an
	embedded clock signal.

In the second example a second S/PDIF cable is used to supply “embedded word clock”. The external device MUST be set to receive external clock via S/PDIF or the units will not be synchronized. The E-MU Digital Audio System is the Master and the external A/D is the Slave.

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