The truth about clocks

No, not that sort of clock! I’m talking about the clocks audio engineers use to synchronise their A/D and D/A converters! And there’s a lot more to them than meets the eye…

Being a fan of simplicity, I don’t come up against clocking issues very often, in fact I’ve only had to ponder the question once, when I was recording 12 channels through my Focusrite Scarlett 18i20, using an extra 8 channels from an Audient ASP-880 via ADAT. And the decision was fairly simple – which of the two units should I use as the clock master? I tried both, and as there didn’t seem to be any noticeable difference, I ended up using the 18i20 as the master.

But the decision is not always that easy, and becomes more difficult the more hardware you need to synchronise. This article from Pink Noise discusses the issue in depth, along with why so many people (including myself, until now) make assumptions about what factors you should consider when choosing your clock master.

Warning: It’s quite long, and has quite a few good links to other sources of info that are also well worth the read, so don’t expect to skim through it and find a golden nugget at the end!

The Future of Clocks: Clarifications in the Audio Clocking Paradigm
by Allen Farmelo
with Matthew Agoglia