Do Balanced Interconnects Really Make a Difference?

[moonlightdrive21]

Hey guys:

Classe states that the use of balanced interconnects on their units will result in much better sound than using RCA interconnects.

But when I talk to certain knowledgable audiophiles about this, they laugh at that statement. The doubters say that balanced is benefical when you have a very long run. But with short runs, there is either no difference in sound quality, or the difference is that the sound is only slightly darker (reducing possible noise), and that there are no other ways the sound could be better.

Any thoughts on this?

Thanks!
Dave

[Kobus]

A great question that I was going to ask someday.

Balanced is supposed to provide a 6 dB gain. Firstly I wonder why that is, and secondly it can only be good.

Remeber we are paying for balanced circuitry inside the components, I suppose we should use them.

After what I have spent on components, I will go balanced even if it only reduces noise slightly.

You know that in this hobby, something like this will bother you until you have done it.

But all that said, I would like to hear some knowledgeable opinions.

ps: And for those who do not know this; there are components that provides for balanced connectors that does not have fully balanced circuits. Classé, not one of them.

Kobus

[Kal Rubinson]

Balanced is supposed to provide a 6 dB gain. Firstly I wonder why that is, and secondly it can only be good.

Well, since there are two driven lines, rather than one in SE, there's 6db more signal to begin with!

Remeber we are paying for balanced circuitry inside the components, I suppose we should use them.

OK. This is not Darwinian: It's not use it or lose it.

After what I have spent on components, I will go balanced even if it only reduces noise slightly.

I use balanced connections in most of my setups mostly because I greatly prefer the postive and reliable physical connection of the XLR vs. the friction-fit of the RCAs. Using 10M interconnects in one system, the SE is as quiet as the BAL.

But all that said, I would like to hear some knowledgeable opinions.

Ooops.

Kal

[ThomasW]

http://www.htguide.com/forum/showthread.php4?t=24295

[NonSense]

Whether or not balanced interconnect make an audible difference, the engineering is sound. Balanced signalling inherently rejects common mode noise. Not only in the cables but throughout the entire circuit which uses a balanced topology. Systems which are designed to take advantage of a balanced design should see benefits beyond just the interconnect. It becomes a means to continue the balanced circuit. (This is usually where you start to spend some coin.)

The extra gain comes from the fact that both the audio signal and its inversion is conducted on the balanced pair as opposed to just the signal referenced to common. The balanced pair provides double the voltage swing peak to peak when compared to just a single signal.

Does this translate into a better audible performance? You can decide.

[Karma]

HI All,
A strong case can be made against balanced operation used in short cable runs. It is very difficult to design a perfectly balanced amplifier. One could say that that no matter how good the design it will be inferior to a single ended approch.

The main reason balanced circuits became available and popular is that many audiophiles use long interconnects and short speaker cables. This is a case where balanced operation makes sense due to the common mode noise rejection. All professional microphone applications use balanced technology because of the extreme sensitivity to noise in a typical microphone situation.

The fact that balanced operation sounds different than single ended is not surprising. Notice I said different, not better. The differences are often (always??) due to imperfections in the balanced circuit design. It is very difficult and always expensive to achieve high end quality.

I prefer single ended because I use short interconnects. I have no need for balanced interfaces.

Sparky

[moonlightdrive21]

Thanks all.

Kal, I'm not clear if you are saying that you beleive the use of balancedwill or will not result in "better sound" compared to using RCA interconnects. If both interconnect types are of equal quality, do you feel balanced connections could often result in noteably better sound quality?

Thanks,
Dave

[Kal Rubinson]

Kal, I'm not clear if you are saying that you beleive the use of balancedwill or will not result in "better sound" compared to using RCA interconnects.

I didn't say. IMHO, there's often a tiny difference in sound but I cannot make any generalization about whether one or the other is "better."

If both interconnect types are of equal quality, do you feel balanced connections could often result in noteably better sound quality?

No. See above.

Kal

[Kobus]

What exactly is meant by 6 dB gain.

Louder !

So can a 100w amp now output 400w. ? Surely not.

Kobus

[NonSense]

The gain is with reference to the signal on the interconnect. The output power will still be limited to the amplifier's capability. It makes little difference. Perhaps an advantage if one of your source components has been placed a significant distance from your pre-amp.

[Kal Rubinson]

What exactly is meant by 6 dB gain.

Louder !

So can a 100w amp now output 400w. ? Surely not.

Kobus

No but it helps the SNR.

Kal

[Kobus]

No but it helps the SNR.

Kal

So the signal is boosted by 6dB and not the noise ?

If so it "sounds good" on paper.

Kobus

[Kal Rubinson]

So the signal is boosted by 6dB and not the noise ?

No but any noise contributed after the boost is, effectively, 6dB lower.

Kal

[Kobus]

No but any noise contributed after the boost is, effectively, 6dB lower.

Kal

Aha, so that is essentially the benefit. Which again "sounds" good.

Thanks Kal.

---------
Kobus

[David Meek]

Anyone want to expand on the difference between fully balanced and not? Inquiring minds. . . .

[Kal Rubinson]

A device can have real balanced inputs but, after the input stage, be single-line (not balanced) all the way through to a single-ended output. Similarly, a single unbalanced device can have a balanced output stage added on. Of course, an unbalanced circuit device can have balanced input and output.

A fully balanced device has separate circuits all the way through for both the + and the - signals, from input to output.

Compare the Sonic Frontiers Line-1 preamp (bal in and out) with the Line-3 (fully balanced).

Kal

[David Meek]

Gotcha. Thanks Kal.

[NonSense]

David

I'm not sure of the context for "fully balanced" which you refer, but I will take a shot.

Fully balanced could be interpreted as when a system maintains true balanced circuitry from the source component to the end of the amplifier chain.

Some systems may offer the balanced interconnect, but the internal circuitry is in fact single ended design. The conversion could be made at the output of the souce/input of the next component etc. There are probably several methods, such as using an active buffer stage, or impedence matching center tapped transformer. (Not fully balanced?) In these situations I would expect inferior performance when compared to a single interconnect due to the extra elements in the path of the balanced interconnect. There are probably less intrusive/superior designs.

Or did you mean something else altogether?

[Chris D]

FWIW, Parasound also has both balanced and RCA jacks on their newer processors and amplifiers. We've had the same discussions in Club Parasound. There's the same gain increase using balanced connections there. But several Parasound owners have actually reported INCREASED background noise using the balanced jacks, usually with more efficient speakers like Klipsch. We think it's because of the gain increase. Because of the reports, I chose to not even try the balanced jacks with my Parasound setup, as I also use Klipsch speakers.

[Kal Rubinson]

FWIW, Parasound also has both balanced and RCA jacks on their newer processors and amplifiers. We've had the same discussions in Club Parasound. There's the same gain increase using balanced connections there. But several Parasound owners have actually reported INCREASED background noise using the balanced jacks, usually with more efficient speakers like Klipsch. We think it's because of the gain increase. Because of the reports, I chose to not even try the balanced jacks with my Parasound setup, as I also use Klipsch speakers.

Well, by its topology, a balanced input has twice the input devices as a single-ended input and they are effectively in series, summing their noise contribution. So, twice the input noise to go with 6dB more gain.

Kal

[Brandon B]

It's nice ot see a well balanced discussion on this, instead of the single ended rants they sometimes turn into.

BB

[David Meek]

Yeah, but just leave it to one unbalanced member. . . . :

[whoaru99]

I heard someone calling my name... :naughty:

[ToddAnisman]

HI-

Want to clear a misconception up-

A Balanced signal is not 6dB hotter than a RCA single ended signal. More like 12dB!!!

Balanced audio runs at 1.24v= +4dBu = -20dBfs (0dBfs is the maximum a digital signal can be).

Unbalanced audio runs at -10dBv, which is a diferent scale than dBu. The difference is about 12dB.

Now there are unbalanced system that run at +4dBu, or other types of gain structure, but they are rare because of the interfacing issues that come up.

The reason that Balanced audio can be noisier is that there is another set of electronics that the signal isrunning into, and if the topology of the system isn't designed for it, then there is no gain from using the Balanced connect no pun intended...)

ALmost all gear is single ended internally. In fact many of the best recording consoles in the world are single ended internally!!!!

Also, the type of balancing design used is critical to sucess when using it. for example, a 600Ohm balanced input stage isn't going to play nice with some modern gear- youll get loading and noise.

So why use balaced audio at all? Well that's simple- Balanced audio can survive in difficult situations where unbalanced audio will succumb to Noise, cross-talk, field hum, and other grounding issues (loops etc).

My advice is to not worry about it too much, unless you are having noise issues or a very complex system.

-Todd A.

[ToddAnisman]

Well, by its topology, a balanced input has twice the input devices as a single-ended input and they are effectively in series, summing their noise contribution. So, twice the input noise to go with 6dB more gain.

Kal

Not quite. In a balanced signal each leg of the signal lines are out of phase with each other, thus when they combine in the gear the noise will cancel itself out (the one side is "flipped" back into phase, the noise is then out of phase...). The only increase in noise would come from the source.

-Todd A.

[whoaru99]

HI-

Want to clear a misconception up-

A Balanced signal is not 6dB hotter than a RCA single ended signal. More like 12dB!!!

Balanced audio runs at 1.24v= +4dBu = -20dBfs (0dBfs is the maximum a digital signal can be).

Unbalanced audio runs at -10dBv, which is a diferent scale than dBu. The difference is about 12dB.

Now there are unbalanced system that run at +4dBu, or other types of gain structure, but they are rare because of the interfacing issues that come up.

-Todd A.

Dunno about all the dBu and dBfs stuff, but I believe the 6dB reference is with respect to the voltage ratio between the two signals. Since the balanced signal voltage is the sum of the opposite "phases" adding together, twice the voltage swing of the unbalanced signal is inherently produced, yes?

[NonSense]

Not quite. In a balanced signal each leg of the signal lines are out of phase with each other, thus when they combine in the gear the noise will cancel itself out (the one side is "flipped" back into phase, the noise is then out of phase...). The only increase in noise would come from the source.

-Todd A.

This only applies to common mode noise. I believe what Kal was refering to was the noise figure. Every additional component in the chain will degrade the quality of the signal to some degree. (The signal will never have a better S/N+D than at the output of the source component) A balanced system is not immune to this type of noise. Since a balanced circuit has twice the components, it stands to reason that it will accumulate twice as much. Essentially offsetting some of the advantage of the extra gain.

[Kal Rubinson]

Not quite. In a balanced signal each leg of the signal lines are out of phase with each other, thus when they combine in the gear the noise will cancel itself out (the one side is "flipped" back into phase, the noise is then out of phase...). The only increase in noise would come from the source.-Todd A.

But random noise pays no attention to the phase of the circuit and is, by definition, not correlated with what is in the other leg. Thus, the input noise of the stage itself is summed.

Kal

[ToddAnisman]

But random noise pays no attention to the phase of the circuit and is, by definition, not correlated with what is in the other leg. Thus, the input noise of the stage itself is summed.

Kal

Yes, But you have to take into consideration the Signal to noise ratio-

If Source X has Y amount of noise, and then Get output to both a balanced audio circuit and an unbalanced audio circuit, then the noise should be the same, assuming that the Amplifer amplifies the signal to the same SPL. If i8t's not, then there is added noise in the Electronics; that does not mean that there is more noise because it's "balanced". To say that a Balanced signal has 6dB more noise beccause it has 2 legs instead of one is simply wrong; however the design of said circuit and how it's implemented could certainly add noise that's not present in the Single ended circuit.

-Todd A.

[ToddAnisman]

This only applies to common mode noise. I believe what Kal was refering to was the noise figure. Every additional component in the chain will degrade the quality of the signal to some degree. (The signal will never have a better S/N+D than at the output of the source component) A balanced system is not immune to this type of noise. Since a balanced circuit has twice the components, it stands to reason that it will accumulate twice as much. Essentially offsetting some of the advantage of the extra gain.

Perhaps in theory. But I think that reasoning is faulty; A properly designed balanced audio circuit is extremely quiet and generally as a rule has a much better S/N ratio than it's unbalanced counterpart.

My experience is in Large studio design and implementation as opposed to Home Theater, so My experience is probably very diffferent than most people here...I think that most people in HT prefer a single ended approach, which is certainly fine, but I find that this is only practical in a very concentrated environment, with hard interconnects. Both of which we rarely see in Pro Audio. ymmv

-Todd A.

[Kal Rubinson]

Yes, But you have to take into consideration the Signal to noise ratio-

If Source X has Y amount of noise, and then Get output to both a balanced audio circuit and an unbalanced audio circuit, then the noise should be the same, assuming that the Amplifer amplifies the signal to the same SPL. If i8t's not, then there is added noise in the Electronics; that does not mean that there is more noise because it's "balanced". To say that a Balanced signal has 6dB more noise beccause it has 2 legs instead of one is simply wrong; however the design of said circuit and how it's implemented could certainly add noise that's not present in the Single ended circuit.
-Todd A.

I never said that a balanced signal has 6dB more noise because it doesn't. What I said was that the input stage's equivalent input noise figure is greater because the two sides add. This is usually below the noise floor defined by the input source and, therefore, usually insignificant.

Kal

[ToddAnisman]

I never said that a balanced signal has 6dB more noise because it doesn't. What I said was that the input stage's equivalent input noise figure is greater because the two sides add. This is usually below the noise floor defined by the input source and, therefore, usually insignificant.

Kal

whatever you say.

Out.

-Todd A.

[David Meek]

Okay, let's not let this degenerate. I've enjoyed the discussion to point - it's always fun to learn - so let's keep it pleasant. If I'm reading too much into this, then please carry on.

[mjb]

As said above, each system (balanced or not) has its place, but IMO, for short inter-connects (<10ft), in the typical living room, going balanced probably isn't going to see any advantage over decent quality unbalanced interconnects. Balanced doesn't just mean three conductor cables, its an entire design philosophy. Many HiFi amps 'cheat' by using XLR connector's but internally unbalanced circuitry.