DMF Posted November 4, 2003 Share Posted November 4, 2003 I'm starting to notice that some of the high-end pre/recv have both unbalance and balanced inputs and line-level outs. Can someone please explain what the practical difference is them and when using a balanced i/f is appropriate? Quote Link to comment Share on other sites More sharing options...
arthurs Posted November 5, 2003 Share Posted November 5, 2003 try this... http://www.balanced.com/faq/balanced.html Quote Link to comment Share on other sites More sharing options...
DMF Posted November 5, 2003 Author Share Posted November 5, 2003 Good reference. Thanks! Quote Link to comment Share on other sites More sharing options...
artto Posted November 5, 2003 Share Posted November 5, 2003 The main benefit of using balanced XLR type cables & connectors is reduced noise, especially in cable lengths longer than 12'. It's used more often in pro audio application where long runs of cables are often necessary. Quote Link to comment Share on other sites More sharing options...
STL Posted February 3, 2004 Share Posted February 3, 2004 Correct me if I am wrong, but it sounds like high-end gearing touting balanced circuitry is probably more hype than anything. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted February 3, 2004 Share Posted February 3, 2004 The XLR is a 3 wire setup. This serves to keep both positive and negative conductors separate from the true ground wire, as RCA type plugs do not have a separate ground wire due to only being 2 wires a positive and a negative. Less signal loss and less interference from outside sources that way. I have found that there is a slight difference between XLR and RCA interconnects even at short distances even as short as 1/2 meter, but don't take that as gospel, that's just my opinion. This is the preferred connector for professional applications and most high-end audio rigs. DM Quote Link to comment Share on other sites More sharing options...
DrWho Posted February 6, 2004 Share Posted February 6, 2004 This serves to keep both positive and negative conductors separate from the true ground wire, as RCA type plugs do not have a separate ground wire due to only being 2 wires a positive and a negative. just to throw out some clarification... there are 3 wires in an XLR. there is one cable carrying the gound just like an RCA cable carries a gound. however, the other two cables are carrying the same signal (not a positive and negative). the cable is made so that the two signal carrying cables are twisted such that as one cable picks up interference, the other cable picks up the same interference with the opposite polarity. when the signal reaches the source, the signal from both cables is then summed. the net result is that the orginal signal passes through unchanged and any interference picked up along the way cancels itself out. another advantage to using XLR... an unbalanced signal has physical limitations to the length of wire runs you can do. i think the limit is 100feet, but don't quote me on that. however, a balanced signal can be run for miles without any integrity loss. i don't know the numbers, but i know the reason for this is due to nominal impedance loads. In the "professional world," cable runs over a thousand feet aren't abnormal. i also know that line-level impedances for balanced and unbalanced are different as well (i think it's 1000 ohms and 300 ohms respectively). the higher impedance also helps to lower the noise floor. or is it the other way around? i forget. all i know is that impedance for balanced cables is such that the noise floor is lower because each amplification stage can be cleaner. i think i should pull out me old text book as i fear im starting to jumble things up (which doesn't help my attempt to clarify some things) maybe someone else will pipe in and help me out (i can't seem to bloody find it). Quote Link to comment Share on other sites More sharing options...
STL Posted February 6, 2004 Share Posted February 6, 2004 ---------------- On 2/6/2004 9:57:28 AM DrWho wrote: just to throw out some clarification... there are 3 wires in an XLR. there is one cable carrying the gound just like an RCA cable carries a gound. however, the other two cables are carrying the same signal (not a positive and negative). the cable is made so that the two signal carrying cables are twisted such that as one cable picks up interference, the other cable picks up the same interference with the opposite polarity. when the signal reaches the source, the signal from both cables is then summed. the net result is that the orginal signal passes through unchanged and any interference picked up along the way cancels itself out. ---------------- Actually your clarification is not quite right. Yes there are 3 wires with one being a true ground. The other two are the signal -- with one being the signal in phase and the other being the signal exactly out of phase. The two signal wires are twisted together so that way any interference that is present up is picked up exactly the same on both signal wires. Then once those signals go into the device the out-of-phase signal in inverted to made it in phase with the other signal and that also makes the noise (which was the same on both wires) exactly out of phase with noise on the other signal wire -- now when both signals are combined the noise cancels itself out! So you see it has nothing to do with cables being made so one one signal wire picks up interference differently than the other -- that would be crazy hard! While I admit XLR cables are ar superior at rejecting noise (and running lost distances) I really don't see any real benefit they have over a well-shielded RCA cable in my audio setup. For home audio, I feel it's all just marketing-hype. Quote Link to comment Share on other sites More sharing options...
Ray Garrison Posted February 6, 2004 Share Posted February 6, 2004 "For home audio, I feel it's all just marketing-hype." Well, maybe yes, maybe no... If the component that is on the receiving end of this signal is constructed so that the signal path is balanced (two isolated, 180 degree out of phase signal paths), then using a single ended (RCA) connector means that some sort of phase splitting / signal inversion stage has to be present, whereas the balanced input would skip that stage. How well this signal split / phase inversion stage is implemented can have a significant impact on whether there is any audible difference between the single ended and balanced inputs. Likewise, if the component is *NOT* using differencial internal paths, then there's got to be some sort of stage converting the balanced input to a single ended input. In either case, you can wind up with one or the other input sounding better. Quote Link to comment Share on other sites More sharing options...
BBB Posted February 6, 2004 Share Posted February 6, 2004 After fooling around with a gazillion miles of cables for nearly 4 decades I go with XLR whenever I can no matter what the length.It saves headaches in the long run. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted February 6, 2004 Share Posted February 6, 2004 My Mac has both RCA and XLR inputs so I have tested both many times with various cables, of course, just trying to answer this very question. I knew some dudes selling various cables who were willing to let me test them out before I bought them. After many different cables I have finally arrived at 1/2 meter pure silver XLR connects as the best of the bunch (and they were actually the cheapest of the silver types!). I do not consider it to be just hype because I checked it out for myself A-B-ing them back and forth. I gave all of my previous copper cabling away as it is not up to the standard that silver cabling presents. The only real recommendation(s) that I would make is two fold: 1) stay as SHORT in length as possible for both types there is a noticable difference between 1/2 meter vs. 1 meter cables regardless of the type 2) go for pure silver wire in either type again a very noticable difference DM Quote Link to comment Share on other sites More sharing options...
DrWho Posted February 6, 2004 Share Posted February 6, 2004 with one being the signal in phase and the other being the signal exactly out of phase. haha, that's what i originally wrote and then i confused myself when i thought about it and ya...thx for the clarification (either way, it was a phase trick to get rid of the noise) one other nice thing about XLR is that the cables lock. never have to worry about loose or finicky connections. granted, for home audio use the huge benefits may not apply but I still think it sounds better. (doing blind A/B tests). the difference is huge. (my testing was done in recording studios, which is similar to HT in the sense of short cable runs). however, if your equipment doesn't use XLR (which almost nothing for HT does because it's too expensive), then it's not a big deal because shielded cables nowadays actually perform very well. Quote Link to comment Share on other sites More sharing options...
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