harmonics and single-ended versus balanced audio cables

[Whatmore]

http://sanderssoundsystems.com/tech...-balanced-vs-unbalanced-operation-white-paper

 

[Yuri Korzunov]

http://sanderssoundsystems.com/tech...-balanced-vs-unbalanced-operation-white-paper

Understand that when music is louder, it sounds better to us. Humans can barely hear the loudness difference when music is played 6 dB louder, so most audiophiles will not recognize that when they switch to balanced operation the music is 6 dB louder. Instead they will recognize that it sounds "better" due to the fact that the music is slightly louder.

I suppose, it is not rare reason of "subjective" sound improvement without checking parameters.

Both will sound identical to human hearing even though balanced operation has slightly more distortion and noise.

What is meant there? Balanced scheme cause more distortions?

In pro audio XLR and TRS used as balanced. But XLR is preferable, because it have lock for avoiding of mechanical disconnection.

 

[Whatmore]

What is meant there? Balanced scheme cause more distortions?

exactly. More measurable noise but still not enough to be audible

 

[Yuri Korzunov]

exactly. More measurable noise but still not enough to be audible

I can't understand: why balanced scheme cause more noise comparing unbalanced one?

 

[Whatmore]

I can't understand: why balanced scheme cause more noise comparing unbalanced one?

the article states (perhaps a bit of a generalisation but still valid IMHO)

Secondly, audiophile equipment usually is very well designed, so there is no audible hum present in it. Therefore the common mode noise rejection feature of balanced operation will not be needed.
Thirdly, audiophiles generally do not like transformers in the signal path. So audiophile equipment does not use balancing transformers. Instead, the conversions back and forth between balanced and unbalanced operation is done using electronics. This adds noise, which does not occur if transformers are used. But both electronics and transformers produce distortion, which degrades the performance slightly compared to unbalanced operation.

 

[Yuri Korzunov]

the article states (perhaps a bit of a generalisation but still valid IMHO)

Agree. Me seems all depend on implementation.

As for balanced as for unbalanced connection we use similar chip amplifier.

In the article said that balanced connection have +6 dB level comparing unbalanced.

So absolute noise increased 6 dB. But signal is increased too. So signal/noise ratio is kept for both cases.

I thing we are more interesting in signal noise ratio, than absolute noise level.

P.S. I like the article. But I just wanted clear some details.

 

[the sound of Tao]

This has been a great thread, thanks Ron for starting it off and also to all for bringing it to light. I've long had a preference for single ended but it's great to get some science behind it.

Generally I've found balanced to tend to have some lower noise and sometimes deeper soundstage with more blackness in the space between instruments but still some sense of overall lost energy or vitality, almost like a slight extra emotional distancing in the presentation. I've equated single ended as somehow simpler and maybe more whole but not quite as differentiated in spatial terms for lack of a better description. Very anecdotal critique tho as I haven't really had the circumstances to do any more rigorous comparison in this. It's like balanced seems to often do better at the context of the sound while single ended maybe has a more expressive musical flow and spirit in a more painterly fashion.

 

[microstrip]

(...) The SET guys follow a less is more philosophy that extends throughout the entire chain. Using balanced outputs of their sources isn't typical usually because while XLR outputs are sometimes provided with pre amps, XLR inputs are even less common.(...)

Just to remember that sometimes the less is more implies that capacitors in the signal path are an enemy - than input and interstage transformers are used in SETs.

 

[DonH50]

Maybe a picture will help... This shows differential with normal (balanced) and single-ended interconnection (IC) ,and single-ended under the same conditions. I show a transformer to perform conversion from balanced to single-ended and vice-versa. These are not meant to be rigorous but show generally what to expect.

There are some assumptions made in Roger's paper that are not always true. A differential circuit will increase the signal by 2, or 6 dB, but uncorrelated noise by only sqrt(2) or 3 dB. That is why differential circuits offer an additional 3 dB of SNR or dynamic range compared to a single-ended circuit.

HTH - Don

 

[Yuri Korzunov]

I can't understand, how to linked changing of amplitudes of 2th and 3th harmonics and impact of "any common-mode noise"?

Or frequency distortions is a feature of L-C of the line?

 

[Ron Resnick]

Despite Don's patient and kind efforts I don't think we are there yet.

. . .

Generally I've found balanced to tend to have some lower noise and sometimes deeper soundstage with more blackness in the space between instruments but still some sense of overall lost energy or vitality, almost like a slight extra emotional distancing in the presentation. I've equated single ended as somehow simpler and maybe more whole but not quite as differentiated in spatial terms for lack of a better description. . . . It's like balanced seems to often do better at the context of the sound while single ended maybe has a more expressive musical flow and spirit in a more painterly fashion.

This is of what I am trying to get to the bottom.

Don/Ken: From an objective, technical (i.e., engineering and electrical) point of view do you have a theory to explain this subjective observation?

 

[DonH50]

Despite Don's patient and kind efforts I don't think we are there yet.




This is of what I am trying to get to the bottom.

Don/Ken: From an objective, technical (i.e., engineering and electrical) point of view do you have a theory to explain this subjective observation?

Assuming "balanced" means "differential" then lower noise, greater dynamic range, better transient response, and higher isolation (better noise rejection) come to mind for the improvements... The rest is so subjective I am not really sure how to respond and anything I would say would lead to another cat fight.

I am not sure I can add much more at this point...

 

[DonH50]

I can't understand, how to linked changing of amplitudes of 2th and 3th harmonics and impact of "any common-mode noise"?

Or frequency distortions is a feature of L-C of the line?

Two different things. Both differential and single-ended circuits add third (odd) harmonic distortion; single-ended also adds second- (even-) order distortion.
Balanced interconnects better reject noise in either case; that is external noise, nothing to do with the internal circuits, since that is for the interconnect and not the actual gain cells.

The interconnect RLC characteristics are not significant and not considered in the pictures.

Differential circuits have an intrinsic noise (dynamic range) advantage but I did not show that. The pictures are busy enough as it is.

 

[Ron Resnick]

1) Could the sound of Tao's subjective observation of ". . . some sense of overall lost energy or vitality, almost like a slight extra emotional distancing in the presentation . . ." be explained by the differential circuits' cancellation of even order distortion products?

2) Or do you explain technically this subjective observation by believing that these subjective impressions are the result of differential circuits' rejection of common mode noise?

 

[Yuri Korzunov]

Two different things. Both differential and single-ended circuits add third (odd) harmonic distortion; single-ended also adds second- (even-) order distortion.

Yes. Harmonics is feature of any active circuits. But I thought, what you meant, what unbalanced connection caused lesser harmonic distortions tnan balanced.

 

[Ken Newton]

Ron, I think that there are too many technical variables to offer an accurate technical causation as to why someone subjectively perceives a certain sound character aside from the primary difference between balanced and unbalanced interconnections. That primary difference between them is that balanced interconnection can reject common-mode noise (signal ground noise) where as unbalanced interconnection cannot. So, I should think that is the reason for any perceived difference, assuming that the gain stages are the same in both cases.

 

[DonH50]

Ron, I think that there are too many technical variables to offer an accurate technical causation as to why someone subjectively perceives a certain sound character via a given system arrangement, aside from the primary difference between balanced and unbalanced interconnections. That primary difference between them is that balanced interconnection can reject common-mode noise (signal ground noise) where as unbalanced interconnection cannot. So, I should think that is the reason for any perceived difference, assuming that the gain stages are the same in both cases.

Agreed, with the caveat that "assuming that the gain stages are the same" is a big assumption not usually valid in these comparisons. As Ken says, too many other variables.

 

[DonH50]

Yes. Harmonics is feature of any active circuits. But I thought, what you meant, what unbalanced connection caused lesser harmonic distortions tnan balanced.

Not unless I got my pictures wrong. Differential circuits do not (ideally) add even-order distortion whilst single-ended circuits do, no matter the interconnection between them, so differential circuits generally have lower overall distortion. (Also lower noise as explained previously but not shown in my pictures.) Balanced connections better reject noise thus a single-ended connection may have a higher noise floor due to any sort of coupled/induced noise.

 

[Ron Resnick]

Thank you, Ken.

My goal for this thread was to achieve an agreed, consensus technical explanation of the subjective observation posted by the sound of Tao.

I think we have achieved a consensus that this subjective observation is explained technically by the cancellation by a differential circuit of

(i) even order distortion or

(ii) common-mode noise or

(iii) both​

(without necessarily achieving agreement on exactly which one is the answer).

 

[Ken Newton]

Thank you, Ken.

My goal for this thread was to achieve an agreed, consensus technical explanation of the subjective observation posted by the sound of Tao.

I think we have achieved agreement that this subjective observation is explained technically by the cancellation by a differential circuit of (i) even order distortion or (ii) common-mode noise or (iii) both.

I suggest that we all make an effort to only use the term 'differential' instead of 'balanced', and 'single-ended' instead of 'unbalanced' when referring to amplification circuits. And likewise, to only use the term 'balanced' instead of 'differential', and 'unbalanced' instead of 'single-ended' when referring to signal interconnections.