# Do balanced (XLR) inputs offer much better sound?



## HanssoN

Do balanced inputs (on a headamp) increase the quality of the sound by a lot, or is the difference subtle?

 Theoretically the quality of the signal would be very close to perfect, (quite a bit better than when using ordinay RCA-inputs), but maybe the overall difference in soung quality isn't that big?

 Thanks,
 HanssoN


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## Hirsch

The one opportunity I had to compare balanced and single-ended versions of a similar cable in a system capable of handling both, I actually preferred the single-ended. 

 Based on my reading, the real advantage of balanced cables enters when dealing with long runs of cable (pro usage). The longer the run of cable, the more important the noise reduction capabilites of the balanced connection become.


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## Rob M

In the PRO arena, gear is rated as +4 db nominal output, and consumer gear is at -10 db.

 This means there is a gain structure challenge between various gear.

 On the PRO side, keyborads, pre's, recorders etc, are used all the time with variables between... depending on the nest o' gear a person may own.

 In the studio, the preferred connection is a balanced line level, because of EMI/RFI etc, and the optimal connectivity would be a line cable, balanced (2 conductors and a shield) at an impedence of 110ohms. Most mastering engineers prefer this because that spec (AES/EBU) will transfer both analog and digtal without complication). IT is more expensive however to wire this way so most folks rely on the standard audio cables.

 Using an XLR does offer a superior signal path, because the ground is not shared but, as we know, all listeners do not have the same perceptives when hearing. So in the end, wire is subjective.

 To that end, there are tons of audiophile sites and Home Theater folks who subscribe to the tenets regarding superior cable etc.

 For the record, and this is not a spam post, so please read in context, the science of making wire has changed over the last several years. The differences are huge anymore between certain brands as well as the costs.

 An associate had asked me to look in on this site, and it's a very comprehensive.

 I would suggest that the listening between the XLR and the single RCA termination, mentioned in the first reply here, perhaps could be, re-evaluated using higher grade component cables.

 I do not assume to say this relative to headphones and would be interested in taking a look at what types of cross platform connectivity solutions we might be able to come up with for this segment.

 AS most headphones I have used, typicallt AKG's studio sets, the preassembled aspects of thse "cans" precludes actual aftermarket application.

 My questions are?

 Is there a standard gauge wire in the signal path from the output jack to the speakers?

 Is there a preference between 1/4" phone TRS (stereo) or 3.5mm TRS (stereo)?

 Thanks for letting me post here.

 Rob


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## HanssoN

Hirsch, was the standard RCA-cable of a higher quality than the XLR? I can't understand why the RCA-cable would sound better, but audio is subjective, and I regard your opinions very highly. Could you please explain the differences in sound?

 Now, I'm going for an amp that's got either balanced OR standard inputs. Unfortunately I can't get an amp with both kinds of sockets, and I'd like to know what you would buy assuming that the amp offering balanced connections costs an additional USD 60.

 PS: I have no need for an interconnect longer than 0,75 metres.


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## Hirsch

Quote:


 _Originally posted by HanssoN _
*Hirsch, was the standard RCA-cable of a higher quality than the XLR? I can't understand why the RCA-cable would sound better, but audio is subjective, and I regard your opinions very highly. Could you please explain the differences in sound?
* 
 

Both were the Virtual Dynamics Nite Series. I suspect a design issue with the balanced cable, because the bass response was awful. Switching to the Cardas Golden Reference (balanced), there was more fine detail than the single-ended Nites, but dynamic range appeared constricted. I've got a prototype cable from Virtual Dynamics (single-ended) that has achieved the level of detail of the Cardas cable while maintaining the dynamic range of the Nites...best of both worlds.


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## Orpheus

no, in most instances, balanced cables (XLR) decrease the sound quality. in order to balance a signal, the original signal has to be put through transformers or other circuitry, which degrades the sound quality. if you are not running a complex system and do not have much interference in the environment, balanced connections are theoretically not desirable.

 that said.... if you have long cable runs, or you have many components, then you might want to use balanced cables for various reasons rob pointed out. balanced cables were developed for the professional community, which has demands a home enthusiast would never encounter.

 if you just have one source, one preamp, and one amp.... well, don't waste your money.


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## Howie

Besides looking at the cable it is also dependent on the design of the component. There may be a difference between full designed components and there may not. You'll have gear that will run better with a balanced connection while you'll have gear that runs better with single ended connection.

 Generally balanced cables lowers the noice floor and is thus recommended however some find single ended cables to be more dynamic and thus prefer it. It is subjective indeed.


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## Orpheus

Quote:


 Generally balanced cables lowers the noice floor 
 

i disagree with that statement. no, balanced cables do not GENERALLY lower noise floor. not when we're talking about home systems. yes when you have more equipment... but no in simple systems.

 you are right that it depends on the design. but even in the most extreme of designs where one complete amp is used for each phase, bypassing transformers and other balancing ciruitry, you STILL have double the circuitry necessary compared to an unbalanced signal. there's no way around it as far as i know. i ain't an e.e. major, but i don't think you need special knowledge to see that putting more in the signal path for the soul purpose of balancing a signal will result in a lower sound quality.

 again, there are many benefits of balanced signals, but these benefits don't help the home enthusiast much.

 (incidentally, Hirsch's observations support my argument.)


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## rohorn

An XLR connection does not always imply a balanced circuit.


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## zzz

Quote:


 _Originally posted by Orpheus _
*in order to balance a signal, the original signal has to be put through transformers or other circuitry, which degrades the sound quality. if you are not running a complex system and do not have much interference in the environment, balanced connections are theoretically not desirable.
* 
 

in most of the big time high-end audio gear (all wadia players/dacs, cary 306/200, and the likes of it) phase inversion aka balancing is performed in the digital domain. positive and inverted components of the signal are then processed independently of each other for as long as it makes sense to. in fact, in most cases in order to obtain an unbalanced output signal, the balanced signal has to go through an additional differential amplifier and a buffer.


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## ServinginEcuador

zzz,

 Are you saying that in the higher end gear that the balanced outputs sound better than the unbalanced? At least when the unbalanced go thru more processing to bring the signal to that unbalanced state.

 I ask as I just got a rather expensive balanced source in hopes that it would provide a cleaner and better sounding signal. The review in Stereo Times says that the balanced in my unit is a bit better than the unbalanced, so I will now have to see for myself once I get the Balanced Gilmore Premier next year. I thought that the balanced outputs were better than the single ended, but have never heard anything above Hirsch's Creek CD53, so I can't speak from too much experience.


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## zzz

Quote:


 _Originally posted by ServinginEcuador _
*Are you saying that in the higher end gear that the balanced outputs sound better than the unbalanced? At least when the unbalanced go thru more processing to bring the signal to that unbalanced state.* 
 

well, I'd be lying if I said I knew, as I have never had a chance to compare one to another just yet. I simply had to mention that the implementation of balanced inputs/outputs does not have to be nearly as bad as orpheus made it look.

 for what it's worth, top of the line pass labs poweramps only have xlr inputs.


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## Orpheus

Quote:


 in most of the big time high-end audio gear (all wadia players/dacs, cary 306/200, and the likes of it) phase inversion aka balancing is performed in the digital domain. positive and inverted components of the signal are then processed independently of each other for as long as it makes sense to. in fact, in most cases in order to obtain an unbalanced output signal, the balanced signal has to go through an additional differential amplifier and a buffer. 
 

well... yes, in your example, using unbalanced cables would definitely sacrificce some sound quality.

 however.... why do these pieces of audio gear balance the signal anyway!? ...as you noted, this results in 2x as many components, and thus less accurate sound.

 so, what i was saying is, all consumer equipment should have RCA's, not XLR's. it does not make sense to use balanced signals in consumer stuff, as it will always result in lower sound quality if one does not take advantage of a balanced signal's ability to reject noise and to avoid some induced hum.

 you see.... the majority of cables used in a simple audio system are maybe 1m in length. maybe a bit longer if you have to. but rarely much longer than 2m. ..........and that's pretty darn short. balanced signals were originally popularized for microphone cables, which often were 50ft all the way to couple hundred feet! at home, in a simple system you'll have maybe 5 components. r components at 1m/pair of interconnects = 10m of cable. .......now, at my house, i estimate about 1/4 MILE!!! of cable.

 so.....yes, if you got a lot of components, balanced signals might make a difference. but please don't buy a piece just cause it is balanced when your system is small. XLR cables do not inheritely result in better sound quality. like everything, it's not as simple as it seems.


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## zzz

Quote:


 _Originally posted by Orpheus _
*however.... why do these pieces of audio gear balance the signal anyway!? ...as you noted, this results in 2x as many components, and thus less accurate sound.* 
 

uhrm. what's your reasoning for the `less accurate sound` thing? if you have two identical blocks of circuitry running side by side processing positive and inverted signals, then the difference between their outputs is 6db larger than either of the outputs but has only 3db more uncorrelated noise, thus right there you effectively get 3db of noise reduction. certain types of distortions/correlated noise cancel each other out (since the stages are presumed to be identical) or at least reduce significantly.


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## Orpheus

yeah... i guess it would cancel each other out somewhat. my reasoning is that you double the ciruitry.... and of course, any ciruitry results in distortion. but yes, i realize it's more complicated than that.

 however, you cannot deny that if such a device did not balance the signal, the signal would be more pure.


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## HanssoN

I finally decided to buy the amp with standard unbalanced inputs... it was a bit cheaper, and I guess it'll do just fine.


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## Howie

Orpheus. What I meant by lower noise floor is that balanced cables reject noice. This is important with long runs. If you are familiar with CJ preamps you would know that they recommend single ended connections. They also seem to be VERY sensitive in terms of cable length and RF interferences. This of course is a design issue.

 I think you will notice a difference when you have a fully balanced system throughout the chain especially if you have long runs.

 The thing is that this argument really isn't too important. What's important is the gear itself. Depending on the gear and subjectivity, the use of balanced cables can have its rewards.

 That said nobody is recommend anyone choosing a piece of gear because they have balanced connections. Just try it out. Balanced cables might give you something that is worth the extra $ while it might be worse. Still I think we can all agree that cable quality is much more important than whether it is balanced or not.


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## Orpheus

Quote:


 Orpheus. What I meant by lower noise floor is that balanced cables reject noice. 
 

yes, i know what you mean. afterall, that's EXACTLY what balanced cables were made for!... but anyway... my point is that in a consumer system, balanced cables don't have much value.


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## Howie

Quote:


 my point is that in a consumer system, balanced cables don't have much value. 
 

I think this is an important point. The definition of "consumer system" is also of great importance.

 If your system isn't revealing enough it would be stupid to spend the money on balanced cables. But if you have a $100,000K system is it still a consumer system? The key is whether you'll hear the difference. It's only worth it if you hear a difference. Your system can be $100,000K and you might not hear a difference while your system might be only $10K and you hear a dramatic difference in noice floor. But in my opinion I think cable and component manufacturer's recommendations generally have something behind it.


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## Orpheus

my definition of a "consumer system" is less than 10 components. has nothing to do with value to me. just the complexity.

 there are cheap and expensive pro audio components, just like cheap and expensive audiophile components. the main difference is just the complexity of the system.

 and like i said before, it doesn't matter how expensive or revealing your system is... if you got only a couple components, balanced cables don't matter at all. and actually hurt the performance. doesn't matter you got a $30,000 turntable, $30,000 preamp, $30,000 amp, $100,000 speakers.................. if you only got these 4 components, balanced cables still do NOTHING for you.

 that's what i meant.


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## Howie

Well I'll never go so far as to say nothing because there are many many happy balanced cable users out there and I know in some instances balanced is required because RCA picked up too much noice.


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## OneMalt

Can someone put this into perspective for me...say in terms of a Max vs. a Blockhead?


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## BoyElroy

Here are excerpts from two white papers; one by Nelson Pass (a) and one from the Atma-Sphere website (b) re: the pros and cons of balanced/differential designs.

 (a) Nelson Pass

  Quote:


 One of the figures of merit for balanced circuits is called the Common Mode Rejection Ratio (CMRR). As previously mentioned, one of the benefits of balanced circuitry is that it amplifies input differences while ignoring or rejecting common signal (noise). The CMRR of this circuit is slightly greater than 80 dB, as illustrated in Figure 13, which shows the performance from 20 Hz to 20 KHz. This is a factor of about 10,000 to 1, so that a 1 volt common input comes out as about .0001 volt when measured differentially at the output.. This figure was achieved with unmatched gain devices, but careful matching does not significantly improve the performance. 
 This figure was achieved differentially at the output. If you are using only one polarity of the output signal, you will find the rejection is only about a factor of 10 (-20 dB). Obviously this isn’t nearly as good, but in point of fact it still represents a factor of 10 better than an unbalanced circuit, and usually this is plenty. I have read assertions that 60 dB CMRR figures are the minimum acceptable, but no good reason to why this figure is essential. In my book, any reduction of noise picked up is a plus.
 In actual practice with real systems, I have noticed that there is usually about a 20 dB difference in background noise between balanced and unbalanced systems, and a circuit with 20 dB rejection will preserve this difference fairly well. As an alternative to having to use the balanced output only, you can replace the resistors R3, R4 and R5, R6 with 40 mA active constant current sources. This will restore the 80 dB CMRR figure for unbalanced output. 
 


 This is from Atma-Speher's website (b):

  Quote:


 Differential Amplifiers

 Figure 2, Differential Amplifier


 Differential amplifiers are the basic building block of our voltage
 amplifiers. Differential amplifiers have a number of advantages over
 conventional single-ended amplifiers. Differential amplifiers are a type
 of balanced amplifier, although certainly not the only type. A
 differential amplifier consists of two single stages of gain, connected
 together by their cathodes (or other emitting devices). This means that
 there two inputs to a differential amplifier and two outputs. Any signal
 at the input of one side of the amplifier will result in two outputs,
 equal but opposite of each other. The main advantages are:

 1. Greater power supply immunity. Differential amplifiers present a
 constant load to the power supply, resulting in less noise in the
 power supply. Differential amplifiers also resist input (noise)
 from the power supply to a much greater degree.

 2. Lower noise. Differential amplifiers have roughly 6 dB lower noise
 then the same circuit executed in a single-ended manner. This can
 be very important in moving-coil preamp sections.

 3. Lower distortion. Differential amplifiers tend to cancel
 distortions that single-ended amplifiers cannot.

 4. Drift is reduced by the tight coupling of the two halves of the
 amplifier. Performance over time is improved.

 5. Noise rejection. Common-mode rejection ratio is the measurement of
 a differential amplifier's ability to not amplify noise that is
 common to both inputs. It is typically at least 55 dB, and can
 approach 140 dB in some critically-tuned designs. 

 There are also some disadvantages:

 1. Increased cost. Differential amplification takes more parts to
 execute. For a given number of stages of gain, differential
 amplifiers have about 50% more parts.

 2. Greater complexity. Although the number of stages of amplification
 remains the same for single-ended and differential amplifiers,
 differential amplifiers have more requirements to execute, for
 example, a negative-voltage power supply. 

 On the bench, in the textbook and in real life, differential
 amplification provides greater performance, particularly from DC to 100
 KHz, the audio region. Reliability in practical terms equals or exceeds
 that of conventional single-ended circuits, if designed properly.


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