Transmitting S/PDIF

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astrolopitec

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Hi
I'm trying to transmit S/PDIF from a Berhinger DEQ2496 to an Audigy2, thirty feet away.
The DEQ's output is balanced and the card's imput is two wires. I've tried it with and without unbalancing transformer, and with all types of wiring combinations with no results.

Am I failing to configure something?

Is it as simple as selecting S/PDIF recording in the sound card's on-screen mixer and then recoding with SoundForge or the likes ?

Should I be able to monitor the sound card's input (to check that sound is comming in) ?

Never done this before. Any hints will be apreciated.

Thanks
Juan
 
How are you connecting this? S/PDIF is connected using a 75 ohm video type coax cable terminated in RCA connectors. And transformers ain't gonna work at all.
 
Mike's right, but just to be clear, S/PDIF is a DIGITAL signal, not analog...........
 
That unit has optical s/pidf. The Audigy (I would assume) has RCA/coax S/pdif. You will need a convertor to go from optical to RCA. Or you will need a convertor to go from AES/EBU to coaxial S/pdif.
 
Thanks guys.
The DEQ2496 has both an optical and a XLR balanced S/PDIF output. I'm trying to work the wire method so as to avoid having to upgrade to a sound card with optical input.

Juan
 
astrolopitec said:
Thanks guys.
The DEQ2496 has both an optical and a XLR balanced S/PDIF output. I'm trying to work the wire method so as to avoid having to upgrade to a sound card with optical input.

Juan
Click to expand...
The xlr is AES/EBU, not S/pdif. That is what is confusing you. AES/EBU is not compatable with S/pdif, you need a converter box.
 
There's no such thing as balanced XLR S/PDIF.... first of all, there's no such thing as a balanced digital signal anyways.

S/PDIF is carried by either optical or RCA-style coax cable ONLY... however, AES/EBU is carried by 110ohm digital cable and uses XLR connectors. AES/EBU is a different digital protocol than S/PDIF and they're often not directly compatible.

So the first step is sorting out exactly what kind of digital I/O your units have, and THEN figuring out how to get them to talk together if they use different protocols.
 
Hi
From the manual...

DIGITAL OUTPUT 1
Type : XLR transformer-balanced
Standard: AES/EBU or S/PDIF
Impedance: 110 ohms
Output level: 3.5 V peak-to-peak

DIGITAL OUTPUT 2
Type: TOSLINK optical
Standard: AES/EBU or S/PDIF

It also says in the digital conections section...
"The AES/EBU interface is largely compatible to the popular S/PDIF interface. A connection can be made using an adapter."
I was hoping that the unbalancing transformer would function as the mistical "adapter".

Any way... While going again over the manual I found a function to switch between AES/EBU and S/PDIF. I bet that could be (part of) my problem.
We'll give it a try.

Thanks again
Juan
 
You should try an XLR to RCA cable. It is true that the information traveling down the wires is (for the most part) the same, the 2 standards differ in the impedance of the cable and the connectors. For short runs this is not a big issue, for long runs, you will have a problem. AES/EBU will handle the long runs. If you have trouble with the XLR to RCA cable, get and AES/EBU to S/pdif converter and put it next to the audigy.
 
Well - proof again that Behringer's QA - including manuals - is faulty.... digital signals are not thought of in terms of balanced/unbalanced, since balanced signals are structly an analog signal concept....

S/PDIF and AES/EBU are two DIFFERENT digital protocols... the actual spec for each defines the type of cable and connectors. They're only compatible with each other if the gear itself is designed to see/distinguish between one or the other.....

BTW - take whatever you read in a Behringer manual with a grain of salt -- I've seen their "writing", on the whole it's rather awful in terms of both clarity and accuracy.
 
Hurray !!!

It works !!!

It turns out that my problem was in the "Creative mixer" setting. I was selecting the "S/PDIF-in" and it turns out that I was coming in through the "CD digital"

It works with both AES/EBU and S/PDIF modes. Just connect pins 2 and 3 of the XLR cable to the sound card with er... Alligator clips !

Thanks guys. You some how managed to jugle my brain.
Juan
 
Blue Bear Sound said:
Well - proof again that Behringer's QA - including manuals - is faulty.... digital signals are not thought of in terms of balanced/unbalanced, since balanced signals are structly an analog signal concept....
Click to expand...

Uh, no they aren't just an analog concept. Here are just a few common digital connection technologies that use differential signalling:

  • RS-422 (mac serial)
  • USB
  • FireWire
  • Serial ATA
  • PCI Express (PCIe)
  • Serial SCSI
  • Differential Parallel SCSI (fairly rare)

Frankly, for interfaces between devices, balanced connections are far more common than unbalanced in the digital world these days.... :D
 
dgatwood said:
Uh, no they aren't just an analog concept. Here are just a few common digital connection technologies that use differential signalling:

  • RS-422 (mac serial)
  • USB
  • FireWire
  • Serial ATA
  • PCI Express (PCIe)
  • Serial SCSI
  • Differential Parallel SCSI (fairly rare)

Frankly, for interfaces between devices, balanced connections are far more common than unbalanced in the digital world these days.... :D
Click to expand...
Well - there ya go - I stand corrected! Thanks for the info, DG!!
 
;)

For the record, it's perfectly possible to use s/pdif signals (sometimes refered to as "consumer format") over an AES/EBU ("Pro format") connection and vice-versa. Some devices actually ignore some of the information in the data stream (flags) that differentiates between the formats.

From what I've been told, the Audigy s/pdif input doesn't give a clean bit-for-bit transfer, it gets resampled to 48Khz, so your best quality would be with the external unit at 48Khz and your recording project also at 48k.
 
Jim Y said:
For the record, it's perfectly possible to use s/pdif signals (sometimes refered to as "consumer format") over an AES/EBU ("Pro format") connection and vice-versa. Some devices actually ignore some of the information in the data stream (flags) that differentiates between the formats.
Click to expand...
Yes - I've mentioned that... but it's not universally compatible... I have a Tascam DA-40 that doesn't communicate with my Masterlink via S/PDIF (even though both units support both protocols).... many manufacturers are somewhat lenient with regards to following the true spec, which results in many incompatibilities...
 
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