S/PDIF stands for Sony/Phillips Digital Interface. It is a 2 channel digital protocol that is used to move 2 channels of digital audio from one device to another. It can either be on an RCA Phono Jack or a Toslink Optical connector.

right, got that and all, but can it be used to connect to another audio device that's amplified so you could run the moto through say, a stereo receiver (like one that's hooked up to your cd player, tape player, etc...) so you can run stuff off of it if say, you're not at "home base" where the monitors and everything else is set up?

And by doing this, I mean have a Y'ed RCA with one at one end coming from the moto spdif out, to the two going to the aux audio in on a receiver/other audio device.

Or is it primarily for hooking up to adats?

I guess I should have been a bit more clear on this...

No
it is not an ADAT thing
it is a domestic digital audio interface

Rane have a very good tech library that can help explain things
http://www.rane.com/library.html

look for
Interfacing AES3 & S/PDIF
http://www.rane.com/note149.html

and look for the Pro Audio Reference
http://www.rane.com/digi-dic.html

yzfwv wrote: right, got that and all, but can it be used to connect to another audio device that's amplified so you could run the moto through say, a stereo receiver (like one that's hooked up to your cd player, tape player, etc...) so you can run stuff off of it if say, you're not at "home base" where the monitors and everything else is set up?

yes, if it has a spdif in.

And by doing this, I mean have a Y'ed RCA with one at one end coming from the moto spdif out, to the two going to the aux audio in on a receiver/other audio device.

GOD NO DON'T DO THAT. Seriously, don't. It's a digital signal, the aux in's on your reciever are going to be analog. You need a DIGITAL input that matches the spdif protocol. Both left and right channels are carried on the one cord (or whatever 2 channels you assign to the output)

Or is it primarily for hooking up to adats?

Nope, Like Kev said, it's a "prosumer" interface. It works well in pro audio applications, but is only 2 channel, where ADAT is 8 channel.

So a fiber optic adat out would be more likely to have 8 channels than the 2 of the spdif?

yes.

8)

Also SPDIF requires a special coaxial cable, it is not your standard RCA-type cable.