The first ASP880 making sure to set the clock mode to external on the back of the unit.

By connecting a BNC cable with a T piece on the end to The Fireface 800 has a word clock output on the unit and so can work with the wordĬlock input of the ASP880s. Two ASP880 mic pre (Slaves) and an RME Fireface 800 audio interface (Master) connected via ADAT along with BNC word clock outputs. Example 2 - Interface as Master with Daisy Chain The only problem with this setup (more of an inconvenience than anything) is that you have to manually change the sample rate on the ASP880 to match the sample rate of the project in your chosen DAW. In this case the ASP880 would need to be the master device by using ADAT which includes clock data in its data stream. The ASP880 has a word clock (BNC) input, but not an optical input so there is no way for the iD22 to be the master in this set up. The iD22 has an ADAT optical out which can be used for slaving devices, but it does not have a word clock output (BNC connector). Example Setups Example 1 - Interface as SlaveĪSP880 mic pre (Master) and an iD22 audio interface (Slave) connected via ADAT: The type of connectors used to clock depends on the equipment being used in the setup (some may only have certain connector types available on the unit) and how many devices are needing to be connected together. When using AES, S/PDIF or ADAT, the clock signal is encoded into the data stream so there is not necessarily a need for a BNC cable to provide a clock signal.

Devices can be connected in daisy chain configuration where a BNC T piece is used to split the clock signal. Other connector types can be used such as RCA in this way as well. Devices can be connected using a BNC cable connected to the “Word Clock In/Out” of the device. ConnectionsĬlocking between devices can be carried out in a few different ways. However this depends on the devices being used. This way, when you open a project in a DAW, the audio interface should change to match the project sample rate, and therefore change the sample rate of all the slave devices. Quite often the best device to set as the master is the one that is connected to the computer (where possible) such as a ProTools Rig or an audio interface. Choosing a Master DeviceĬhoosing the master device is usually very flexible. The master clock signal can either come from the internal clock on the master device, or you can get a separate, dedicated unit. The device which is providing the clock signal is known as the master, while all the units accepting this clock signal are referred to as slave devices. When syncing two or more devices, there needs to be one unit that is providing the clock signal to all the rest of the units. If one is spinning faster than the other, the teeth will not interlock and the system won’t work. They have to be spinning at the same rate for the cogs to mesh together.

A simple analogy explaining the need for syncing two devices with a clock signal is by imagining two spinning cogs. Multiple devices need to be synced so the digital audio being transferred between them is read correctly. When you are only looking to use one unit, such as an audio interface, you don’t really have to worry too much about clocking, however when using multiple units it becomes a little more complex. If the clock frequency changes, it is known as “Drift”. When the clock is not consistent in its timing, the resulting distortion is known as “Jitter”. If this does not happen, the amplitude of the signal will not be recorded or played back at the correct time and so distortion will be introduced into the signal. Samples are taken many times a second, and need to occur at regular intervals (44.1 kHz is the sample rate used in commercial CD audio). Digital audio is made up of amplitude values of a signal at different points in time (known as samples). In A to D and D to A conversion, the digital signal needs to be clocked accurately to prevent distortion.

Extend mic cables or word clock cable