Using External Clock Sources (for Recording and Monitoring)

When recording or monitoring, Pro Tools can synchronize to an external clock source. Options for external clock vary according to the type of Pro Tools system you are using.

Avid HDX, Pro Tools|HD, and HD Native Systems

Avid HDX, Pro Tools|HD, and HD Native systems can receive external clock through any of the digital inputs on any Avid HD audio interface (including AES/EBU, S/PDIF, and Optical).

For details on audio interface connections, see the guide for your audio interface.

To select an external clock source for Avid HDX, Pro Tools|HD, or HD Native systems:

1 Choose Setup > Hardware.

2 Select the appropriate audio interface in order to display its settings in the Main page.

3 If necessary, enable the appropriate Digital Format (if you have not already done so, according to the instructions in your User Guide or I/O Guide).

4 Set the Clock Source to match the type of input.

5 Configure input routing of the digital source, using the Input and Output pop-up menus, if necessary.

6 Click OK to close the Hardware Setup dialog.

Pro Tools Systems with 003, 003 Rack+, 003 Rack, Digi 002, or Digi 002 Rack

Pro Tools can receive external clock from the Optical input or S/PDIF input.

To select an external clock source for a Pro Tools system with 003, 003 Rack+, 003 Rack, Digi 002, Digi 002 Rack:

1 Choose Setup > Hardware.

2 Set the Clock Source to match the type of input.

3 If you select Optical, make sure the Optical Format matches the type of optical input you are sending to your Pro Tools system.

If you set the Optical Format to S/PDIF, Pro Tools will watch the Optical port for external clock, and ignore any clock input on the S/PDIF RCA jacks.

Pro Tools Systems with Eleven Rack

Pro Tools can receive external clock from the AES/EBU input or S/PDIF input.

To select an external clock source for Eleven Rack:

1 Choose Setup > Hardware.

2 Set the Clock Source to match the type of input.

Pro Tools Systems with Mbox Pro, Mbox 2 Pro, Mbox (3rd generation), or Mbox 2

Pro Tools can receive external clock from the S/PDIF input on these interfaces.

To select an external clock source from Pro Tools with an Mbox Pro, Mbox 2 Pro, Mbox (3rd generation), or Mbox 2:

1 Choose Setup > Hardware.

2 Select SPDIF (Windows) or SPDIF/RCA (Mac) from the Clock Source pop-up menu.

3 Click OK.

Your digital input device must be connected and powered on for Pro Tools to synchronize to it. If your input device is not powered on, leave the Clock Source set to Internal.