# Balanced, Unbalanced, XLR, SPDIF?



## daffa

Can somebody explain me the difference between balanced and unbalanced cables, as well as their differences from the RCA? Also, I want to know the XLR, SPDIF and the coaxial cable. For what purpose they are made?
 I am upgrading my source and I want to make sure I pick the right source with right inputs/outputs and the dedicated cables.
 Thanks
 DJ


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## chillysalsa

The balanced connectors are explained nicely on this site here. XLR connectors basically offer cleaner sound by virtually eliminating background noise using a shield/ground wire. Most higher end sources will have XLR (or 'AES/EBU') analogue outputs for this reason. XLR also work on 4 Volts, so they can typically send stronger signals compared to the unbalanced 2 volt RCA connectors.

 Coaxial wires are used for connecting DIGITAL signals, and can have standard RCA connectors, XLR, or BNC. They use two conductors and there is a lot of debate over which connector offers the lowest digital jitter. SPDIF (Sony/Philips Digital Interface) is not a type of connector, but the format / system for sending digital audio. SPDIF can be RCA, XLR, BNC, or even fiber optic (Toslink).


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## Orpheus

"Most higher end sources will have XLR (or 'AES/EBU') analogue outputs for this reason. XLR also work on 4 Volts, so they can typically send stronger signals compared to the unbalanced 2 volt RCA connectors."

 correction-- AES/EBU is a DIGITAL format carried by balanced cables. pro equipment usually has AES/EBU rather than SPDIF.

 note that XLR is not always the better solution. balanced cables were invented for long cable runs where noise is a larger issue than with the relatively short cables used in home systems. but in order to balance the signal, transformers or other solutions must be used, which alters the original signal. having an unbalanced output (RCA) insures a pure signal in most circumstances........ but there are plenty of exceptions.

 i do not see why balanced cables (XLR) would be beneficial for home systems.


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## Calanctus

Quote:


 _Originally posted by Orpheus _
 [B
 i do not see why balanced cables (XLR) would be beneficial for home systems. [/B] 
 

There are plenty of reviews of home audio components that sound better with balanced connections than with unbalanced.


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## Orpheus

yes, there are. you're right--there are plenty who would say balanced lines sound better. and perhaps they are right too.... in fact, i am SURE they believe that it does sound better........

 however, for most designs, balancing the signal should result in a degredation of fidelity, not an increase. the benefits come from noise rejection, which could otherwise be very loud in long cable runs. otherwise, you are adding more stages in the signal path, and virtually doubling the amount of wire used in the cable.

 anyway.... arguing about this is pretty much like arguing that certain cables sound better. i will tell you, balanced cables are inheritently less "pure" than unbalanced lines. that is a FACT (at least for all but the most extravagant of designs.) just like it's a fact that vinyl is vastly lower fedelity than the CD, at least in any measurable terms..... and i's also a fact that frequency response among cables is practically immeasurable............

 but that does not mean that one will not "hear" a pleasurable difference.

 but anyway.... just letting you know.

 i would like to just point out briefly that there are many high-end cables that do not even have shielding: Kimber, Nordost, etc.... so, you can see what many people think about the need for extra noise rejection....


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## chillysalsa

Quote:


 _Originally posted by Orpheus _
*correction-- AES/EBU is a DIGITAL format carried by balanced cables. pro equipment usually has AES/EBU rather than SPDIF. * 
 

 Oh. that's right. Thanks.


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