Hi, I'm looking at updating my gear, but am not 100% sure how I could connect them all together. I might be over thinking it, but I'm confused as to how I could connect them all together digitally, and what would be the master word clock, and if I would suffer if I did it wrong.

I already have a Focusrite Saffire 40, and am looking at getting both the Focusrite Octopre, which would have an ADAT connection, simple enough, with the octopre being the master clock. I am also looking at the SSL Alpha channel, with the SPDIF output to the saffire 40, Alpha being the master (I think? Only at 44.1 I think, but I'm not bothered about that).

So this is where I'm confused, if I had them all, I could connect the octopre through ADAT and the Alpha channel through SPDIF, so what would be the master? And how do I sync them all?

I don't really want to jack the Alpha to the saffire 40, seeing as I can use the digital on the alpha.

I am quite confused, and might be over thinking it! But thanks for any help!

Quote Jonny Duddle:

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I already have a Focusrite Saffire 40, and am looking at getting ... the Focusrite Octopre, which would have an ADAT connection ... with the octopre being the master clock.

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Makes sense... and so far so good!

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I am also looking at the SSL Alpha channel, with the SPDIF output to the saffire 40, Alpha being the master

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There can only be one master in a system. Everything else has to slave. They can slave from an external wordclock supplied by the master, or to the embedded clock within the ADAT or S/PDIF connection.

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if I had them all, I could connect the octopre through ADAT and the Alpha channel through SPDIF, so what would be the master?

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Which ever one you choose. The A-D converter which works least well when clocked externally is the best one to make the master... but generally I would go for which ever preamp will be your primary preamp as master.

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And how do I sync them all?

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1. Decide which one is the master, and set it to run on its internal clock at the desired sample rate. 2. Figure out how best to make everything else slaves.

The saffire can obviously slave to either the ADAT or SPDIF input, so that's not a problem. The trick will be figuring out how to slave the second preamp from the first or the Saffire... and that's where your trouble lies.

Pro gear has wordclock in and out, so configuring clocking is trivially simple. Semi-pro gear like this doesn't, which makaes hybrid systems a nightmare.

The Alpha has an S/PDIF in and out, but no wordclock. The Octopre has wordclock in but nothing else. And the Saffire has S/PDIF and ADAT in and out.

So the simplest solution would be to use the Octopre as the master. Set the Saffire to salve to the ADAT input from the Octopre. The take the S/PDIF out of the Saffire and route that to the Alpha, and set the Alpha to slave to its S/PDIF input. It's not a very elegant solution, but hopefully it will work.

A better alternative would be to invest in a master clock unit (like one of the Drawmer units), and use that to send wordclock to the Octopre, S/PDIF to the Alpha, and let the Saffire salve to one of its inputs.

And a better best still would be to buy interfaces that are properly equipped to make external clocking as easy as it should be!

hugh

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Technical Editor, Sound On Sound

Thanks a lot for your very informative reply!

That does sound like the simplest solution, saving a fair few hundred quid on a master clock at least.

Would there be any way of checking if it is all working correctly?

Set a hardware synth or an analogue test oscillator to generate a high pitched pure sine tone (around 3kHz is best). Feed that into a channel of each preamp, and listen to the signal reaching the DAW. If it is clean and glitch or disortion free, all is good. If you hear regular ticks of clicks, then something isn't being clocked properly.

Hugh

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Technical Editor, Sound On Sound

Thanks a lot! I'll give that a go when it's all up and running. I do really appreciate SOS and it's forums, really do learn a lot and save a lot of trouble!