Is Digital Coax the same as S/PDIF? at DVinfo.net

Deke Ryland · July 24th, 2007, 06:32 PM

Hey guys.. I need to connect my two Edirol Studio Monitors with an S/PDIF cable and I have a digital coaxial cable here laying around. My question is:

Is a digital coaxial cable (package doesn't say anything about S/PDIF on it) the same as an S/PDIF cable?

Emre Safak · July 24th, 2007, 07:02 PM

If I understand correctly, S/PDIF is what goes down the cable. You can use two types: coaxial or optical, so if your cable meets the S/PDIF specs then it should be fine, but I don't know what the specs are... I can't see any harm in trying.

Steve House · July 25th, 2007, 04:47 AM

S/PDIF specs call for 75 ohm unbalanced cabling which is the same cable as is commonly used for composite video. And FYI, AES/EBU specs call for 110 ohm balanced.

Ty Ford · July 25th, 2007, 05:54 AM

Shhhh! Don't tell anyone, but I've used short runs (1-2 feet) of high grade audio cable with RCAa on each end for S/PDIF.

Your cable should be OK.

Regards,

Ty Ford

A. J. deLange · July 25th, 2007, 09:21 AM

While S/PDIF is a standard which includes details of the signalling i.e. bit rates, voltages, cable impedance (75 ohm) and type (unbalanced coaxial), coding ( bi-phase mark) frame markers, data bit assignments....) most coaxial cables sold for "digital audio", especially if for the consumer market, are intended for use with S/PDIF and are thus entirely suitable. As others have noted the cheapest piece of coax from Radio Shack, even though it be 50 Ohms and leak like a sieve may very well work just fine for short runs. That's the good news and bad news about digital. It either works or it doesn't.

Jon Fairhurst · July 27th, 2007, 10:26 PM

Quote:

Originally Posted by Ty Ford

Shhhh! Don't tell anyone, but I've used short runs (1-2 feet) of high grade audio cable with RCAa on each end for S/PDIF.

I won't say a word - as long as you don't tell anybody that I've use LOW grade audio cables for about 3 ft without problems. (It was just a loop-back test.)

As said above, use a composite video cable - the ones with the yellow ends - to run within spec.

Glenn Davidson · July 27th, 2007, 10:39 PM

That's right, if they didn't want us using audio cables, why the RCA connector. Besides my 50 dollar Wydeeye Apogee gold plated 75 ohm digital s/pdif cable works like crap.

Jon Fairhurst · July 28th, 2007, 03:19 PM

Quote:

Originally Posted by Glenn Davidson

...Besides my 50 dollar Wydeeye Apogee gold plated 75 ohm digital s/pdif cable works like crap.

How long is the run?

Glenn Davidson · July 28th, 2007, 07:07 PM

It's a short jumper. The problem is the design of the crimp on connectors. Both center pins are loose and do not make good contact.

Jon Fairhurst · July 29th, 2007, 02:52 PM

You'd think the plug and jack manufacturers could figure out how to follow a 50 year old (?) spec by now!

July 24th, 2007, 06:32 PM	#1
Deke Ryland Major Player Join Date: Nov 2006 Location: Washington, USA Posts: 213	Is Digital Coax the same as S/PDIF? Hey guys.. I need to connect my two Edirol Studio Monitors with an S/PDIF cable and I have a digital coaxial cable here laying around. My question is: Is a digital coaxial cable (package doesn't say anything about S/PDIF on it) the same as an S/PDIF cable?

July 25th, 2007, 04:47 AM	#3
Steve House Inner Circle Join Date: Mar 2005 Location: Hamilton, Ontario, Canada Posts: 5,742	S/PDIF specs call for 75 ohm unbalanced cabling which is the same cable as is commonly used for composite video. And FYI, AES/EBU specs call for 110 ohm balanced. __________________ Good news, Cousins! This week's chocolate ration is 15 grams! Last edited by Steve House; July 25th, 2007 at 06:12 AM.

July 25th, 2007, 05:54 AM	#4
Ty Ford Inner Circle Join Date: Nov 2004 Location: Baltimore, MD USA Posts: 2,337	Shhhh! Don't tell anyone, but I've used short runs (1-2 feet) of high grade audio cable with RCAa on each end for S/PDIF. Your cable should be OK. Regards, Ty Ford __________________ Ty Ford's Audio Bootcamp Field Guide Ty Ford's Audio Video Blog

July 29th, 2007, 02:52 PM	#10
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	You'd think the plug and jack manufacturers could figure out how to follow a 50 year old (?) spec by now! __________________ Jon Fairhurst

July 24th, 2007, 07:02 PM	#2
Emre Safak Trustee Join Date: Feb 2004 Location: Brookline, MA Posts: 1,447	If I understand correctly, S/PDIF is what goes down the cable. You can use two types: coaxial or optical, so if your cable meets the S/PDIF specs then it should be fine, but I don't know what the specs are... I can't see any harm in trying.

July 25th, 2007, 09:21 AM	#5
A. J. deLange Major Player Join Date: Jun 2004 Location: McLean, VA United States Posts: 749	While S/PDIF is a standard which includes details of the signalling i.e. bit rates, voltages, cable impedance (75 ohm) and type (unbalanced coaxial), coding ( bi-phase mark) frame markers, data bit assignments....) most coaxial cables sold for "digital audio", especially if for the consumer market, are intended for use with S/PDIF and are thus entirely suitable. As others have noted the cheapest piece of coax from Radio Shack, even though it be 50 Ohms and leak like a sieve may very well work just fine for short runs. That's the good news and bad news about digital. It either works or it doesn't.

July 27th, 2007, 10:39 PM	#7
Glenn Davidson Major Player Join Date: Dec 2005 Location: Nevada City, California Posts: 499	That's right, if they didn't want us using audio cables, why the RCA connector. Besides my 50 dollar Wydeeye Apogee gold plated 75 ohm digital s/pdif cable works like crap.

July 28th, 2007, 07:07 PM	#9
Glenn Davidson Major Player Join Date: Dec 2005 Location: Nevada City, California Posts: 499	It's a short jumper. The problem is the design of the crimp on connectors. Both center pins are loose and do not make good contact.