Creative 1820M, 1212M owner manual Getting in Sync, External Device supplies Master Clock, Via Adat

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

(via ADAT)

The lightpipe carries eight channels of audio data and an embedded clock.

ADAT Out

1	2	3	4	5	6	7	8
Master

External A/D - D/A Converter

Set PatchMix DSP to receive:

External ADAT Sync

Slave

PatchMix DSP supplies Master Clock

EXTERNAL (via ADAT)

This lightpipe carries eight channels of audio data.

	Set External Device to receive:
ADAT Out	External ADAT Sync

1	2	3	4	5	6	7	8
Slave

ADAT In

External A/D - D/A Converter

	This lightpipe carries an
	embedded clock signal
Master	& eight channels of audio.

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.

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