HD24/96 Technical Reference

97

An example of how two HDRs can be synchronized to a VTR using video is shown below:

Video / Word Clock

Generator

Blackburst

Blackburst

Blackburst

Video Slave

 

Video Slave

 

VTR

Video Slave

In this setup each of the three devices is a video slave to the master video generator. This setup works well when digital audio is signals are NOT connected between the digital audio devices, but will not work when the digital audio signals are connected between the devices. The setup shown below illustrates this very common mistake.

Video / Word Clock

Generator

Blackburst

Blackburst

Blackburst

VTR

Video Slave

Digital Audio

Video Slave

Video Slave

When digital audio signals are connected between digital audio devices it is imperative that their clocks be synchronized to a common word clock source, regardless of whether or not video synchronization is involved.

Digital audio devices expect to receive digital audio signals within a certain “window” of time relative to the start of the word clock signal. If it receives them outside the time window, the data may not be read properly and you get a “pop” in your audio. Video signals do not