Simple Graphical Guide on Single-Ended vs. Balanced Audio with Headphones
Feb 24, 2020 at 4:25 AM Thread Starter Post #1 of 15

ClieOS

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Wrote this for some place else but I guess it is just as relevant here. Probably be better to post it in the Wiki section, but it doesn't seem to be working right after the forum update. So here it is.

G1E.jpg


A ‘single-ended’ source is the kind of normal audio source with a 3.5mm or 6.35mm stereo socket. It has a left and right channel going to the headphone’s drivers and a ground channel going back to source to complete the circuit. In a single-ended circuit, only left and right channel carry active signal while the ground channel doesn’t (passive / zero volt). FIG 1 is a simple representation of how most single-ended setup looks like

G2E.jpg


The origin of balanced audio is really from pro-audio’s stage usage. In a pro-audio environment that usually involves a lot of different very powerful electronic equipment running on the same time, RF interference can easy cause a lot of noise to a single-ended circuit, especially when long transmitting cable is used (which acts more or less like an antenna). The idea of balanced audio is to generate an inverted signal from the left and right channel, thus resulting in Left+ (original left signal), Right+ (original right signal), Left- (inverted left signal) and Right-(inverted right single). When the two pair of signal are sent over distance, any extra signal that can’t be cancelled out by the opposite pair can be identified as noise caused by the RF interference and subsequently being eliminated to reproduce the clean left and right signals. However, the inherent benefit of driving headphone with balanced signal is not because of noise, as headphone generally doesn’t have nearly as long a cable as pro-audio usage and thus doesn’t pick up much interference, but because balanced audio has: (1) Double the slew rate when compared to single-ended circuit as the opposite (inverted) signals having a ‘push-pull’ like relationship when compared to single-ended circuit where left / right signals are sinking into the same zero volt ground channel. This results in better transient for balanced audio. (2) Better channel separation since balanced audio does not share a common ground channel (which in fact is not requited in balanced headphone setup). Some might think balanced output on the same source will always give double the driving power than single-ended output – this is however not always true, depends on how the source is designed. With the right design, it is possible that the single-ended output performs just as good as the balanced output. FIG 2 is a simple representation of how most balanced setup looks like.

G3E.jpg


FIG 3 shows how the Pentaconn 4.4mm connection can also be used to power a single-ended headphone even though the source has a balanced output. This will required both the source and headphone to be designed and wired correctly. Not all Pentaconn 4.4mm equipped balanced source can be utilized in such way and you should consult with the source’s manufacturer first.

G4E.jpg


FIG 4 shows how you can convert a balanced headphone with the right adapter to be used on a single-ended source. Basically the adapter will short the headphone’s Left- and Right- wires together to be used as ground channel and effective turns it into the same configuration as a single-ended headphone.

G5E.jpg


FIG 5 shows you instead an incorrect utilization of adapter to connect a single-ended headphone to a balanced source. While you can convert balanced headphone to single-ended configuration by adapter, you cannot convert single-ended headphone to balanced configuration by a simple adapter. You will need to rewire a single-ended headphone’s cable in order to create a separated path for the individual Left+, Right+, Left-, and Right- signal – and an adapter will not do that. What this kind of adapter does is to simply short circuit the Left- and Right- channel together. Unlike ground channel, which has zero volt, Left- and Right- are active channel and they will not cancel each other out. In the best case scenario where the source has built-in protection circuit, using this kind of incorrect adapter will only decrease the sound quality and performance of the whole setup, besides messing up the stereo image of the music. In the worst case scenario where the source does not have any built-in protection circuit, it is possible to permanently damage the source’s circuit. In other words, never try to connect a single-ended headphone to a balanced source (with the only exception of what shown in FIG 3). Sometime you will find people selling this kind of adapter on ebay, Taobao or Aliexpress – do not get fooled!
 
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Feb 24, 2020 at 4:36 AM Post #3 of 15
Pardon me, but I am a little confused per quote:

Some might think balanced output on the same source will always give double the driving power than single-ended output – this is however not always true, depends on how the source is designed. With the right design, it is possible that the single-ended output performs just as good as the balanced output

End quote
Yes, technically, balanced is more powerful....but then...I question

So, with the right design, SE can sound just as good as balanced ? Then the double slew rate and better separation due to not using the same common ground won’t be the real advantages ?
 
Feb 24, 2020 at 5:39 AM Post #4 of 15
Pardon me, but I am a little confused per quote:

Some might think balanced output on the same source will always give double the driving power than single-ended output – this is however not always true, depends on how the source is designed. With the right design, it is possible that the single-ended output performs just as good as the balanced output

End quote
Yes, technically, balanced is more powerful....but then...I question

So, with the right design, SE can sound just as good as balanced ? Then the double slew rate and better separation due to not using the same common ground won’t be the real advantages ?

Good question.

Let simplify it and assume the SE circuit in question is made out of just one opamp ("X"), then a balanced circuit based on the same design will requite 2 opamp X per channel;(one for original signal and one for inverted signal). Opamp X has a slew rate of Y (and thus SE circuit has a slew rate of Y) - since balanced circuit has a push-pull like effect, 2 opamp X will give you slew rate of 2Y (one pushing and one pulling) - but that is only limited to the condition that the balanced circuit is double of the same SE circuit, which might not be always the case.

Say you build the balanced circuit with 2 opamp X that give you slew rate of 2Y, but you build the SE circuit with another, faster opamp ("Z") that already has a 2Y slew rate - then obviously the slew rate of both your balanced (2 opamp X) and SE circuit (1 opamp Z) will be the same - this is what I mean by 'the right design' - There is no rule that mandate anyone to build their SE circuit as half of the balanced circuit (or balanced circuit as double the SE circuit) inside the same source. By creating two different circuits with different parts, it is possible to get very similar performance.

This is also the same reason why some balanced output do not have double the output power as the SE output on the same source - because they can be different circuit in parts or design.

SE separation on the other hand is harder to get as good as balanced simply because of the share ground channel - but it can be designed to be good enough to compete with balanced circuit.
 
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May 20, 2020 at 3:43 PM Post #5 of 15
Nicely explained. Agree on all.
May I add to this.
small portable DAC/amps such as Fiio or ES100, max. power output is limited by their battery's voltage, this is usually low.
there are ways to boost this, one is a DC to DC conversion to boost the voltage, but not very practical, as it produces a lot of noise, costs too much.
Another way is to use two amps, or even two DAC-Amps.
There are a number of off-the-shelf chips available from the likes of SABRE, that are a DAC chip with an amp onboard!
They are cheap enough, so two are used per channel (or a stereo chip). the signal being fed to one DAC is digitally inverted to produce a left-inverted and right-inverted, as well as standard right and left.
using the output from these stereo chips, a balanced output can be obtained, that has twice the slew rate, twice the voltage swing (4 times the power) and some unwanted common artefacts can be rejected by the nature of the "push-pull" analogy already mentioned.
This explains why such devices, produce more power in balanced mode, use more battery juice, and possibly sound better. By completely separating the right and left channel DAC-Amps, stereo separation can improve too.
I offered a simple explanation of this phenomena here:
https://www.head-fi.org/showcase/fiio-btr5.24178/reviews
 
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Jan 5, 2021 at 8:48 PM Post #7 of 15
Quick bump
 
Jan 7, 2021 at 4:29 PM Post #8 of 15
I take advantage of this thread (as i know you don't write anymore in the earbuds one) to personally thank you for being THE driving force of the earbuds thread and contributing to my discovering of this wonderful category of gears, which I dismissed for so many years, thinking earbuds were things of the past! :face_palm:

As I just registered to Head-Fi a few days ago I didn't have the opportunity before to thank you for your great contribution, so that is done now! :relaxed:

Oh, and sorry for derailing this thread, i go back in the shade now... :flushed:
 
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Aug 23, 2022 at 2:37 AM Post #11 of 15
Wrote this for some place else but I guess it is just as relevant here. Probably be better to post it in the Wiki section, but it doesn't seem to be working right after the forum update. So here it is.

G1E.jpg


A ‘single-ended’ source is the kind of normal audio source with a 3.5mm or 6.35mm stereo socket. It has a left and right channel going to the headphone’s drivers and a ground channel going back to source to complete the circuit. In a single-ended circuit, only left and right channel carry active signal while the ground channel doesn’t (passive / zero volt). FIG 1 is a simple representation of how most single-ended setup looks like

G2E.jpg


The origin of balanced audio is really from pro-audio’s stage usage. In a pro-audio environment that usually involves a lot of different very powerful electronic equipment running on the same time, RF interference can easy cause a lot of noise to a single-ended circuit, especially when long transmitting cable is used (which acts more or less like an antenna). The idea of balanced audio is to generate an inverted signal from the left and right channel, thus resulting in Left+ (original left signal), Right+ (original right signal), Left- (inverted left signal) and Right-(inverted right single). When the two pair of signal are sent over distance, any extra signal that can’t be cancelled out by the opposite pair can be identified as noise caused by the RF interference and subsequently being eliminated to reproduce the clean left and right signals. However, the inherent benefit of driving headphone with balanced signal is not because of noise, as headphone generally doesn’t have nearly as long a cable as pro-audio usage and thus doesn’t pick up much interference, but because balanced audio has: (1) Double the slew rate when compared to single-ended circuit as the opposite (inverted) signals having a ‘push-pull’ like relationship when compared to single-ended circuit where left / right signals are sinking into the same zero volt ground channel. This results in better transient for balanced audio. (2) Better channel separation since balanced audio does not share a common ground channel (which in fact is not requited in balanced headphone setup). Some might think balanced output on the same source will always give double the driving power than single-ended output – this is however not always true, depends on how the source is designed. With the right design, it is possible that the single-ended output performs just as good as the balanced output. FIG 2 is a simple representation of how most balanced setup looks like.

G3E.jpg


FIG 3 shows how the Pentaconn 4.4mm connection can also be used to power a single-ended headphone even though the source has a balanced output. This will required both the source and headphone to be designed and wired correctly. Not all Pentaconn 4.4mm equipped balanced source can be utilized in such way and you should consult with the source’s manufacturer first.

G4E.jpg


FIG 4 shows how you can convert a balanced headphone with the right adapter to be used on a single-ended source. Basically the adapter will short the headphone’s Left- and Right- wires together to be used as ground channel and effective turns it into the same configuration as a single-ended headphone.

G5E.jpg


FIG 5 shows you instead an incorrect utilization of adapter to connect a single-ended headphone to a balanced source. While you can convert balanced headphone to single-ended configuration by adapter, you cannot convert single-ended headphone to balanced configuration by a simple adapter. You will need to rewire a single-ended headphone’s cable in order to create a separated path for the individual Left+, Right+, Left-, and Right- signal – and an adapter will not do that. What this kind of adapter does is to simply short circuit the Left- and Right- channel together. Unlike ground channel, which has zero volt, Left- and Right- are active channel and they will not cancel each other out. In the best case scenario where the source has built-in protection circuit, using this kind of incorrect adapter will only decrease the sound quality and performance of the whole setup, besides messing up the stereo image of the music. In the worst case scenario where the source does not have any built-in protection circuit, it is possible to permanently damage the source’s circuit. In other words, never try to connect a single-ended headphone to a balanced source (with the only exception of what shown in FIG 3). Sometime you will find people selling this kind of adapter on ebay, Taobao or Aliexpress – do not get fooled!

Hello.

I have come to this post through your signature when reading another comment of yours, and I find it very useful, and very well explained. Thanks.

There is a topic that has always intrigued me, and that I have not been answered in the DIY cables forum, nor have I been able to find it in search engines: there are many IEM cables today, which combine materials. Let's say half silver and half copper cores, or silver main cores with a copper mesh, for example. In that case, how would they be connected? I understand that in balanced connections, the silver cores would go to the positives, and the copper or mesh ones to the negatives, and in the SEs to ground.

These cables are offered with different terminations, but I think the benefit is different in SE than in balanced. Connecting the return of a silver wire with copper to ground can save cost, but I don't think it has sound benefits. In the case of balanced connections, spreading the signal over different media on the positive or negative can create strange effects that are not in the original recording. I'm not saying they can't be very good cables, but I don't know if it makes much sense.

I do believe in the difference between cables, and that I have invested in cables for my headphones and IEM, immediately noticing the difference, but I have had this doubt for a long time.

Thank you very much.
 
Aug 23, 2022 at 8:37 PM Post #12 of 15
Hello.

I have come to this post through your signature when reading another comment of yours, and I find it very useful, and very well explained. Thanks.

There is a topic that has always intrigued me, and that I have not been answered in the DIY cables forum, nor have I been able to find it in search engines: there are many IEM cables today, which combine materials. Let's say half silver and half copper cores, or silver main cores with a copper mesh, for example. In that case, how would they be connected? I understand that in balanced connections, the silver cores would go to the positives, and the copper or mesh ones to the negatives, and in the SEs to ground.

These cables are offered with different terminations, but I think the benefit is different in SE than in balanced. Connecting the return of a silver wire with copper to ground can save cost, but I don't think it has sound benefits. In the case of balanced connections, spreading the signal over different media on the positive or negative can create strange effects that are not in the original recording. I'm not saying they can't be very good cables, but I don't know if it makes much sense.

I do believe in the difference between cables, and that I have invested in cables for my headphones and IEM, immediately noticing the difference, but I have had this doubt for a long time.

Thank you very much.

Different benefit of wire composition (or the lack thereof) is still a heavily debated topic in some forum. I am not an expert of the field and don't hold any strong option one way or another. I do however like to keep it simple when it comes to headphone cable so I mostly used Neotech UP-OCC cable, either pure copper or silver plated copper, as Neotech has good reputation and can be found on reasonable price.
 
Mar 27, 2023 at 8:45 PM Post #13 of 15
Hi mister @ClieOS Thanks so much for the huge explanation you just gave us. I my self find it very helpful... however i'm very noob to this hobby and i have a question i can not resolve and / or find a clearer answer..

The kinera nanna 2.0 pro is an iem model that is 6 balanced armature and comes with a 4.4mm balanced cable, however in their website the same enterprise sells them with the option to have a single ended 3.5mm stereo swappable head, so you could just take the 4.4 mm jack out and use the same cable with the single ended conector.

My question is ¿can i use these iems with the single ended 3.5mm jack to my single ended amp?? (Schiit modi+ and magni+ stack).

There is also a certain nice cables that have swappable/ interchangeable heads jack terminations (3.5 mm, 4.4 mm, 6.3mm) using the same cable just plugging in / out the desired jack.

https://hifigo.com/blogs/news/letshuoer-x-z-reviews-chimera-iem-upgrade-modular-cable

I know balanced gear as cables, 4.4mm jacks, and balanced armature iems should be paired with balanced amps/ dacs

But my question is

Can i use any balanced armature [headphones / iems] with this type of wires and plug them into any single ended amp??

Thanks so much for your time
 
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Mar 27, 2023 at 10:00 PM Post #14 of 15
...

I know balanced gear as cables, 4.4mm jacks, and balanced armature iems should be paired with balanced amps/ dacs
,,,

Not really. You can use Balanced Armature IEM with both single-ended and balanced DAC/amp.

The word 'balanced' in balanced armature is there to describe that, inside the transducer, there is an armature that is balanced between two magnets. The word 'balanced' in balanced audio is however there to describe that each channel's outputted electrical signals are in identical but opposite polarity a la balanced configuration (*or more precisely, in 'differential', the word 'balanced' was used wrongly in the beginning but we get used to it and didn't bother to correct it back).

So one is describing the design of a structure, while the other is describing the status of electrical signals. They have no real correlation. to each other besides the fact that both use the same English word.

To answer your last question: Yes, you can plug any balanced armature IEM to single-ended DAC/amp as long as IEM has the right cable configuration.
 
Mar 27, 2023 at 10:16 PM Post #15 of 15
Thank you so much for your fast answer i really appreciate it and your time for reading my nasty long text.

So now i'll save money and buy all the headphones and or iems that i thought were only worth it if you own a balanced [dac/amp].

Also from your above explanation i understood plugging any single ended jack to a true balanced amp could short circuit and kill the amp.

But plugging balanced headphones to single ended amps will not cause any harm.

I feel so much safer now, will never end to thank you enough.
 

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