Time clock sync devices

@lordmelton Thank you very much!

It might help to know what you're planning to use it with.  In my case, it was a complete waste of money as the device I used it with already had an excellent internal clock.

Master clocks are most often used to synchronize multiple devices in a studio environment. 

Read up on them a little.  Here's a short high-level overview 

@big_greg thank you for your answer. I recently bought a CEC transport (TL 2N) and I am planning to sync it to my dac (CH PRECISION C1), which can accept a clock sync board. I must admit that it sounds wonderfully as it is! I don’t know if it is worth buying the sync board plus a digital cable!

Hopefully someone that has owned that combination can chime in. 

Yep, clocks are critical to digital. And as  big_greg referenced one can overdue it, the internal clocks may be sufficient, adding external or more clocks and/ or mismatched clocks may disturb sound quality.  Somewhat recently I experienced what I presume was effect of this when after adding a switch to network I suddenly noticed excessively precise imaging. Other than that one episode, better clocks have always resulted in better sound quality for me.