spdif question

[ESPplayer7]

hey guys, i was wondering when and what you would use this for, i know its for digital recording. Does it work like anyother connection to record, like a 1/4 jack that you plug into your soundcard, hit record, then play? Im going to be using a line 6 pod and it has an out for this, thanks

 

[dgatwood]

hey guys, i was wondering when and what you would use this for, i know its for digital recording. Does it work like anyother connection to record, like a 1/4 jack that you plug into your soundcard, hit record, then play? Im going to be using a line 6 pod and it has an out for this, thanks

You can connect an S/PDIF output to an S/PDIF input and it dumps audio data across as a series of bits, so in that regard, yes, it behaves just like any other audio connection except that what feeds into it has to come from another device's S/PDIF output.

Depending on the device, there are two different types of S/PDIF. Be sure you understand the difference before you try to work with S/PDIF connections; the two types require conversion hardware to go between them.

The first type is coaxial (copper-based). This always uses an RCA connector (pin in the center with a ring of shield prongs around the outside). With this type of connection, you need a 75 ohm coaxial cable. The easiest way to get one is to buy a standard cable TV wire with screw-on F connectors on the end, then buy adapters from F to RCA. You should be able to easily find these adapters at Wal-Mart, Radio Shack, etc. (I recommend screw-on cable TV wires because the push-on variety are too easy to disconnect accidentally.)

The second is optical. It can either use a square connector (TOSLink, just like you probably have on the back of your stereo if it is recent) or an 1/8" mini connector. That last one looks like a normal 1/8" mini plug. This is common on laptops and some inexpensive sound cards so that they can use a single jack for a headphone output and a digital output to your stereo.

You should be aware that if you have an 1/8" mini connector marked as S/PDIF, that is optical S/PDIF, so any electrical contacts on the jack are almost always analog, not digital. If you need to connect an optical S/PDIF connection to a coaxial S/PDIF input, you'll need to use an optical-to-coaxial S/PDIF converter. (You should be able to find these for under $30, and possibly under $20.) Converters are also available in the reverse direction. Be sure you get the direction right; those converters are not reversible.

If you need to adapt between 1/8" optical and TOSLink optical, many commercially available TOSLink cables come with an appropriate adapter on one or both ends.

There's also a balanced line variant called AES/EBU that uses an XLR cable, but you probably won't ever encounter that....

 

[SouthSIDE Glen]

That last one looks like a normal 1/8" mini plug.
...
You should be aware that if you have an 1/8" mini connector marked as S/PDIF, that is optical S/PDIF, so any electrical contacts on the jack are almost always analog, not digital.

Hey, dg,

First, welcome back! Haven't seen you around this forum in a while .

Second, I have to admit, this third kind of S/PDIF connection is a new one on me; I'm familiar with the RCA and the TOS lightpipe types, but this 1/8" mini has me a bit confused.

Are you saying that it is a dual-purposed jack, that it can handle *either* standard mini-jack analog (at which levels?) or a fiber optic connection, depending upon which you plug into it?

G.

 

[jeremyball]

You most likely have the RCA type of connection - it is the most common, as far as I know. Remember that S/PDIF is a digital 2-track output (as is AES/EBU). I use it on my mixer to record direct to disk on my final mix.

The sound is better because it keeps the output from Logic/Pro Tools in digital format, and there isn't any unncessary A/D or D/A conversion (you will experience a loss of quality when you have multiple, unnecessary A/D D/A conversions).

(Side note...)

S/PDIF is considered "consumer" standard, and "AES/EBU" is considered a professional standard. That is because S/PDIF is unbalanced, but is fine for short runs. The AES/EBU uses a RCA-type, balanced connector. The sound quality is exactly the same though... as long as there isn't any interference on the S/PDIF connection.