Pro Tools
®
HD card
The Pro Tools
®
HD card is designed to operate as a Clock Slave, locking to a clock reference signal provided by the audio unit
connected to its primary port. The interface unit can define the sample rate internally, or can itself be synchronized to an
external reference signal (e.g. WordClock).
Whenever the user selects a sample rate setting in the PC or Mac software, the corresponding command is sent to the interface
unit.
Delta-Link MADI HD
The Delta-Link MADI HD, like the Pro Tools
®
HD card, is designed to operate as a Clock Slave. Once the card and
Delta-Link MADI HD are connected together, they can be seen as a unit requiring an external clock reference signal. However,
this unit now has MADI ports, instead of the “Digital and Analogue” connections to other devices provided by Pro Tools
®
interfaces.
Although a reference signal is embedded in the Primary port, the MADI connection requires a separate WordClock signal.
Therefore, the Delta-Link MADI HD is equipped with a WordClock input connector.
Depending on the type of unit that is connected to the MADI port, the sample rate will no longer change automatically when
a setting is selected in the PC or Mac software (because there is no command channel). Therefore, the sample rate must be set
manually at both ends (in the Pro Tools
®
software
and
on the hardware connected to the MADI port).
10
4. Synchronization
