Additional preamps and your interface – clock this!

When you plugin your mic or instrument, fire up your interface and hit record in your DAW, you’re converting those analogue sounds into digital data. You’ve selected a sample rate, and everything’s playing together nicely. Now you want to record the band, so you pick up a preamp expander, hook it up via ADAT, and now you need to think about clocking…

Audio interface clocking

All (well, a bit) about digital clocking

With just that one piece of gear connected to your DAW, everything’s nice and easy, those samples are getting, well, sampled, at a nice steady frequency and all is click-free and well. When you add another piece of digital gear, you need to get those samples in sync, or you’re going to get clicks and distortions, and that’s where digital clocking becomes important.

One important thing to consider is the whole clock master and clock slave thing. To sum up, you want one of your digital devices to take control of the situation (the master) and send clocking information to everything else in the system (the slave(s)). If this can be your interface, that’s great, as that should all then link to the sample rate in your DAW nicely. Whether or not you can make that happen depends on the digital connectivity on your devices, and it may not always be possible…

Preamp interface clocking

Let’s say you’ve got a preamp with just an ADAT output, connected to a preamp with just an ADAT input; what do you have to do to get everything on the same page? There’s no way for the interface to send clocking information to the preamp in that situation as the digital signal flow is exclusively preamp -> interface.

Fortunately, the ADAT stream can carry clocking information. So, in this situation, you would have to set the preamp as the clock master, and the interface as the slave, configured to sync to the embedded clock in the ADAT stream. All well and good, but just remember to set the sample rate on the preamp to match your DAW session!

Thank you Audient!

There are myriad setups all dependent on how much digital gear you have and what connectivity options they have: ADAT, S/PDIF, AES, wordclock… So a huge thanks to Audient for producing this fantastic clocking reference! Oh, and they make some cracking interfaces and preamps as well…

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Fynn Callum

producer, guitarist, engineer & dj
From indie guitarist to deep house producer via Northern Soul dj; mix engineer, producer and gear enthusiast. Jaffa Cake aficionado.

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