Verifying Word Clock Sync Between Devices and the Digital 8•Bus

•When the D8B is set to “Internal” in the Apogee Clock pop-up window, it generates word clock as a master device. All other devices must be connected as slaves.

•If the D8B is slaved properly to a master word clock source, “Locked.” is displayed in the Setup>Digital I/O window next to the Apogee Clock pop-up window and an asterisk (*) flashes in the right-most portion of the control surface VFD.

•If the D8B is improperly connected as a slave to the digital network, “Lock Error.” is displayed in the Setup>Digital I/O window next to the Apogee Clock pop-up window and a question mark (?) flashes in the right-most portion of the control surface VFD.

You probably have a bad word clock sync connection if:

•You hear audio but it cuts in and out at regular intervals.

•There is no audio signal at the input of the D8B even though everything seems to be connected properly.

•All meters are full on and you hear a very ugly grating, grinding, static sound.

•When the record/playback device transport is engaged, you see a question mark flashing in the right-most portion of the control surface VFD.

Troubleshooting Word Clock Problems

•Troubleshoot through the system from the master through the slaves. Connect the first two devices and verify their functionality. Once they’re up and running, add the next device, and so on. This is the most efficient manner to check out a system.

•Verify connection, integrity, and quality of all sync cables.

•Verify a consistent sample rate setting on all connected sync devices (all set to the same sample rate—44.1, 48k, etc.)

•Verify that the master sync source word clock output is connected to the word clock input of the slave, and that additional slaves also receive word clock. Slaves can either receive word clock directly from the master device or daisy-chained through connected slaves. Patch word clock out of a connected slave into the word clock input of any other slave.

•Verify that the master device word clock status is set to INTERNAL.

•Verify that all slave devices are set to follow EXTERNAL word clock.

•If the system doesn’t seem to work correctly, you might have an intermittent or broken sync cable.

Always use high-quality 75Ω BNC word clock cables.

D8B Manual • Chapter 4 • page 110