[levtbinh]

I found from many threads on this forum and other places in the internet to claim that there is a big difference between XLR (balance) vs SE cable.
 
I don't quite believe in that claim, especially for a 10ft headphone cable.
 
However, considering the full system DAC --> Amp --> Headphone, I have some questions that need your help: 
 
1) For DAC --> Amp connection, are there any differences in sound quality between XLR vs RCA?
    If there are, are they positive and audible?
 
2) If DAC --> Amp connection is already XLR, will there be any differences if the connection Amp --> Headphone is XLR or SE?
    If there are, are they audible?
 
If these questions have been answered any where, could you give me a link to it?
 
Thank a lot in advance 

 

[Steve Eddy]

Generally speaking, unless you're dealing with unusually long runs, or are working in an unusually noisy environment, balanced doesn't really bring anything to the table.

se

 

[nigeljames]

  I found from many threads on this forum and other places in the internet to claim that there is a big difference between XLR (balance) vs SE cable.
 
I don't quite believe in that claim, especially for a 10ft headphone cable.
 
However, considering the full system DAC --> Amp --> Headphone, I have some questions that need your help: 
 
1) For DAC --> Amp connection, are there any differences in sound quality between XLR vs RCA?
    If there are, are they positive and audible?
 
2) If DAC --> Amp connection is already XLR, will there be any differences if the connection Amp --> Headphone is XLR or SE?
    If there are, are they audible?
 
If these questions have been answered any where, could you give me a link to it?
 
Thank a lot in advance 

 
With regards to the cable itself there is no difference whether it's XLR or RCA, unless you are using long lengths when XLR will be preferable.
 
However the advantage of XLR is
1. If the DAC is designed to perform better if balanced out is used
2. The amp is designed to perform better if balanced in is used, and
3. If amp is designed to perform better if balanced headphone output is used
 
So it's more of an issue as to how to get your gear to perform at it's best. If you have balanced gear then it is probably designed, if done properly, to be used balanced and that means using XLR cables.

 

[levtbinh]

Generally speaking, unless you're dealing with unusually long runs, or are working in an unusually noisy environment, balanced doesn't really bring anything to the table.

se

 


Quote:

   
With regards to the cable itself there is no difference whether it's XLR or RCA, unless you are using long lengths when XLR will be preferable.
 
However the advantage of XLR is
1. If the DAC is designed to perform better if balanced out is used
2. The amp is designed to perform better if balanced in is used, and
3. If amp is designed to perform better if balanced headphone output is used
 
So it's more of an issue as to how to get your gear to perform at it's best. If you have balanced gear then it is probably designed, if done properly, to be used balanced and that means using XLR cables.

 
Thank you for your prompt reply. I get the point about the cable itself.
 
From your reply, I have some further questions:
 
1) Provided that both DAC and Amp are properly designed for both RCA and XLR (is it possible?), does XLR have any advantage to produce better sound quality?
 
2) If using XLR connection between DAC --> Amp gives a better result than RCA, the headphone cable, whether XLR or SE, doesn't make any difference.
    So don't we need a "full" balanced system to enjoy the benefit of XLR connection between DAC --> Amp?
 
Thank you.

 

[nigeljames]

   
Thank you for your prompt reply. I get the point about the cable itself.
 
From your reply, I have some further questions:
 
1) Provided that both DAC and Amp are properly designed for both RCA and XLR (is it possible?), does XLR have any advantage to produce better sound quality?
 
2) If using XLR connection between DAC --> Amp gives a better result than RCA, the headphone cable, whether XLR or SE, doesn't make any difference.
    So don't we need a "full" balanced system to enjoy the benefit of XLR connection between DAC --> Amp?
 
Thank you.

It's important to realize that not all balanced amps are equal as there are different ways to get a balanced output. Some require a balanced input for balanced output. Some balance internally a single ended input and some do both.
 
1. If by saying that you mean 'SQ is equal via XLR & RCA' then I don't see the point of the amp/dac being balanced in the first place if there is no SQ benefit. I assume there are amps with RCA & XLR inputs and outputs where you can't tell the difference and in that case I would ask the question as to whether the amp.dac are really balanced. Take the Hifiman EF-6 amp. It as RCA inputs but has RCA and XLR outputs but is not a balanced design.
 
2. If you have a fully balanced signal from DAC to Amp then you would normally want that signal to remain balanced going to the phones. Therefore the headphone cable needs to be balanced else you are potentially losing any benefit.

 

[Steve Eddy]

It's important to realize that not all balanced amps are equal as there are different ways to get a balanced output. Some require a balanced input for balanced output. Some balance internally a single ended input and some do both.

1. If by saying that you mean 'SQ is equal via XLR & RCA' then I don't see the point of the amp/dac being balanced in the first place if there is no SQ benefit. I assume there are amps with RCA & XLR inputs and outputs where you can't tell the difference and in that case I would ask the question as to whether the amp.dac are really balanced. Take the Hifiman EF-6 amp. It as RCA inputs but has RCA and XLR outputs but is not a balanced design.

2. If you have a fully balanced signal from DAC to Amp then you would normally want that signal to remain balanced going to the phones. Therefore the headphone cable needs to be balanced else you are potentially losing any benefit.

Could you give an example of a benefit outside of common-mode noise rejection?

se

 

[nigeljames]

Could you give an example of a benefit outside of common-mode noise rejection?

se

 
The benefit has nothing to do with the cable itself but the components that it is being used with. If any component is designed to be used a certain way then it will perform better when used that way.
 
The cable/connection is only an issue, as previously stated, if long runs are used otherwise the question to be asked is 'is my DAC/Amp designed to be used balanced?'
 
If the answer is yes then use balanced cables to get the best results. If the answer is no then it's either a badly designed balanced amp or not really balanced in the first place.
 
I don't know why any reputable company would produce a balanced amp unless it provides some benefit over a single ended alternative.
 
I know my, properly designed, balanced amp sounds better when used fully balanced and many other users will testify to that.

 

[cjl]

  I don't know why any reputable company would produce a balanced amp unless it provides some benefit over a single ended alternative.
 
I know my, properly designed, balanced amp sounds better when used fully balanced and many other users will testify to that.

The cynical (and probably correct) view is that companies would produce a balanced amp because some audiophiles will pay more for one, even though they tend to have no real advantage for driving a headphone.
 
(As for your amp sounding better than a competent single-ended design, have you done a double blind level matched test to verify that?)

 

[Steve Eddy]

I don't know why any reputable company would produce a balanced amp unless it provides some benefit over a single ended alternative.

Never heard of marketing? "Balanced" has a certain cachet and most people don't have any real understanding of it other than "it's what the pros use."

I know my, properly designed, balanced amp sounds better when used fully balanced and many other users will testify to that.

And I can point to people who say their system sounds better after they've out photographs of themselves in their freezer (not making this up).

se

 

[nigeljames]

Never heard of marketing? "Balanced" has a certain cachet and most people don't have any real understanding of it other than "it's what the pros use."
And I can point to people who say their system sounds better after they've out photographs of themselves in their freezer (not making this up).

se

I did say 'reputable' !
 
 
I never said, and it was not my intention to imply, that my amp is better because it is a balanced design. Balanced does not intrinsically mean better.
 
What I was stating was that my amp is designed as a balanced amp and to be used ideally in a balanced system. As I know my amp sounds better if balanced inputs & outputs are used ( and many Audio-gd users will testify to the same ) .
I thought I had made my point that a proper balanced amp would sound at it's best when used as a balanced amp hence the reason XLR should be used if its meant to be used.
 
It is not a comparison of balanced and unbalanced amps.

 

[nigeljames]

(As for your amp sounding better than a competent single-ended design, have you done a double blind level matched test to verify that?)

 Who said that, I didn't.
 
I meant my amp sounds better when used as it was meant to be used, and that's balanced.
 
It impossible, and ridiculous, to say amp A is better (or worse) than amp B simply because it's balanced.

 

[Steve Eddy]

I did say 'reputable' !

Who are some "reputable" manufacturers that don't use marketing techniques? I don't believe I can come up with a single company that doesn't.

I never said, and it was not my intention to imply, that my amp is better because it is a balanced design. Balanced does not intrinsically mean better.

What I was stating was that my amp is designed as a balanced amp and to be used ideally in a balanced system. As I know my amp sounds better if balanced inputs & outputs are used ( and many Audio-gd users will testify to the same ) .
I thought I had made my point that a proper balanced amp would sound at it's best when used as a balanced amp hence the reason XLR should be used if its meant to be used.

Keeping in mind that this is the Sound Science forum, have you done and level-matched, blind testing to determine if anyone can reliably tell the difference between the balanced and unbalanced outputs on an amp that offers both?

It is not a comparison of balanced and unbalanced amps.

Yes, I understand that.

se

 

[sludgeogre]

It all depends on the equipment you have. Some balanced amps are single ended at some point, so they're just expensive and pointless. Some amps have a hardware summer to add the phases back together for single ended output, so all you're doing is undoing all of the work your balanced circuitry just did. This is fine if you just want to hook up to other equipment that isn't balanced, or whatever your heart desires, but you are willingly paying for circuitry that is meant to reduce noise only to put it into technology that doesn't use the same precautions.

As far as actually NEEDING balanced equipment, the idea seems silly to me for home use. Balanced designs were invented by engineers who were working in studios and other environments with a lot of equipment and noise all over the place. They needed something that would be invulnerable to heavy amounts of noise. In my home, all I have is my computer and a few LCD screens that don't put off any noise, so why would I need my technology to be invulnerable to noise? In addition to this, balanced designs require a ton of extra equipment to make it balanced, so some argue that single ended sounds better in the right environment.

As for using a single ended cable on a balanced amp, you're just adding some kind of summing into the signal path, so its one more thing to add noise to your signal chain. If the equipment is balanced properly, then you will probably get better performance from a fully balanced signal chain. 

 

[Steve Eddy]

It all depends on the equipment you have. Some balanced amps are single ended at some point, so they're just expensive and pointless. Some amps have a hardware summer to add the phases back together for single ended output, so all you're doing is undoing all of the work your balanced circuitry just did.

The purpose of a balanced input is to reject any common mode noise picked up by the cable that's feeding it. Once it has been rejected, it's gone. It doesn't magically re-appear at some point later down the signal chain so I fail to see how a ingle ended output in any way undoes the work that has benn done by the balanced input.

As far as actually NEEDING balanced equipment, the idea seems silly to me for home use. Balanced designs were invented by engineers who were working in studios and other environments with a lot of equipment and noise all over the place.

Balanced interfaces pre-dated recording studios by a fairly wide margin. They were first used in the early days of the telephone in the late 19th century and much later found their way into recording studios. Audio owes quite a lot to the telecommunications industry, namely AT&T/Bell Labs.

As for using a single ended cable on a balanced amp, you're just adding some kind of summing into the signal path, so its one more thing to add noise to your signal chain. If the equipment is balanced properly, then you will probably get better performance from a fully balanced signal chain. 

Actually, "balanced" as it is typically used in the headphone industry, is just bridging together two amplifier channels which adds more noise and distortion.

se

 

[sludgeogre]

The purpose of a balanced input is to reject any common mode noise picked up by the cable that's feeding it. Once it has been rejected, it's gone. It doesn't magically re-appear at some point later down the signal chain so I fail to see how a ingle ended output in any way undoes the work that has benn done by the balanced input.
 

All I mean is that any noise that is present in the room is just going to be picked up by whatever is single ended. If the system isn't fully balanced, then the system is susceptible to noise, but not the balanced parts. Saying that it is "undone" was definitely the wrong word.
 
I have been reading about all of the ways phone companies pioneered audio, including making PCM widely used and such. I wasn't aware that they invented balanced systems either. Thanks for the history lesson. I have also seen the horrible balanced implementations you're talking about. It is pretty strange what people will do to call a system balanced.