harmonics and single-ended versus balanced audio cables
- Thread starter Ron Resnick
- Start date
I suppose, it is not rare reason of "subjective" sound improvement without checking parameters.
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.
I can't understand: why balanced scheme cause more noise comparing unbalanced one?
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.
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.
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.
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.
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
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
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?
Or frequency distortions is a feature of L-C of the line?
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?
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...
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.
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?
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?
Yes. Harmonics is feature of any active circuits. But I thought, what you meant, what unbalanced connection caused lesser harmonic distortions tnan balanced.
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.
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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.
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.
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
(without necessarily achieving agreement on exactly which one is the answer).
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
(ii) common-mode noise or
(iii) both
(without necessarily achieving agreement on exactly which one is the answer).
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.
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