Using the ADAT inputs on MOTU 828 mkII

[xSALx]

The other day I saw an article with a guy who used an old ADAT for extra line inputs plugged into the ADAT input into the converter. Easy 8 discrete line ins.

How would this work? I'm assuming this would work in real time? Also would there be any a-d coversion going on. Would the channels going through ADAT go into the computer be in 24 bit?

How good of an idea is this? And have any of you tried this? It be nice to have 16 line in channels instead of 8. At this point ADATs are so cheap that a couple hundred bucks would be worth the extra 8 channels.

[jrsgodfrey]

I do this sometimes since I have an old adat lying around.

You would be using the adat's converters, which are either 16 or 20 bit -- but the files created will be at whatever depth you choose in the software ( I use DP). You also should conncect the adat out from the interface to the adat (I use an 828) and clock the adat to the interface.

It's still the adat's converters, so its a "good idea" if you need 8 more real time inputs (and outputs) and you have an adat around. That's how I use it.

IMO, buying an adat for this isn't a great idea, when even the cheapest adat converters -- behringers, alesis AI-3, etc. -- are several generations newer and pass 24bits.

[xSALx]

I was hoping that the signal would just pass through. Another question...if I were to get a one of those new MOTU Ultralites that have 8 lines, to daisy chain it to my 828, how important is a external clock? Could I get away without getting one, without too many problems?

[jrsgodfrey]

You won't have any problems w/o a master clock. Just choose which of the MOTU devices will be the master. The Ultra Lite doesn't have dedicated word clock I/O, so you would have to clock via spdif or adat. Spdif would be the preferable of the two, and you could keep it hooked up w/ a nice short hi-quality coax cable.

Those two together sound like a good solution -- portability w/ the Ultra, and extra inputs in the studio when you need 'em.

I wonder how the ultra really performs on bus power, though.

[effector]

Spdif would be the preferable of the two

why is that?

[jrsgodfrey]

why is that?

Less susceptible to jitter, or so I've always been told.

With OSX, though, the whole thing would probably sync via the firewire connection. Not sure about that, though.