Word Clock

[alexly123]

I'm referring to what I've seen named "word clocks", I've also heard "master clock" around that topic (??).

 

I'm fairly confused about this concept. I've done light researching and can tell it's not the most easy information to find. So I figured I could get some help here

 

What is it and its purpose? Why would I need or want it? How does it work and how would I set it up?

 

Edit: On this Image what Is that switch referring to?

 

Thanks!

-Alex

[SSL]

It's for synchronizing audio devices to a master clock that determines the sampling rate, ensuring that there is low jitter and no time misalignment amonst the various D/A and A/D components. If you only have the one interface in the audio chain, you don't need a separate clock to manage multiple devices.

[alexly123]

So with two devices you simply connect their word inputs and outputs? Otherwise it is best (or required) to use a master clock?

[anothertom]

59 minutes ago, alexly123 said:

So with two devices you simply connect their word inputs and outputs? Otherwise it is best (or required) to use a master clock?

Often you would have a dedicated clock generator with multiple outputs, rather than using one built into an already complicated device, but if you have something with a generator as an additional feature then you can use that. Also, if you only had two pieces of equipment, you would designate a master and a slave by connecting the output of the master to the input of the slave, leaving the other connections empty, rather than creating a loop.

 

It's worth noting that a word clock is very much unneeded with today's hardware outside of the highest level production, and by that i mean, as you're asking these questions there's no reason for you to be concerned by not using one.

On 14/07/2017 at 3:20 AM, alexly123 said:

Edit: On this Image what Is that switch referring to?

Without knowing the exact device I can but guess, and you should reference the user manual for an accurate answer. 

The top row could be switching whether it uses an external clock, the bottom row switching between passing the signal through or producing a clock output. The far right setting might read an external clock and an active split on the output. the 75 ohm marking is just stating the nominal impedance of the connection.

[kasugatei]

Also, in addition, digital connections such as ADAT, AES, S/PDIF are carrying clock pulse signals as well. So, if you have interface + eg. 8ch ADAT A/DC you can use it without word clock since they can be synced via ADAT. However, you should make sure that you have correct interface settings for that operation.