Balanced vs Single Ended (SE) sound

[brucew268]

Someone was reminding me that most “balanced” amplifiers are actually single-ended with some added circuitry to balance the signal. Since I’ve run balanced for the last few years preamp>amp and also source>preamp, it seemed reasonable to try SE again, following the idea that simpler circuits are better for sound.

In my system that did not at all turn out to be the case! The balanced route had significantly more realistic piano and cymbals, harmonics, textures, inner detail, bass pitch, with better sound stage depth and 3D sense.

So why would that be? I first thought it might be the choice of interconnect that I was using in the SE config. But then I used the same interconnect in a balanced termination and found that was not even a little bit of the cause.

So either the opamps and extra circuitry in the balanced config produce better sound than the subset SE circuit… or the noise rejection capabilities of balanced interconnects reveals how much RFI I have behind that equipment rack!

Any other ideas?

[loo]

Hi lots of balanced amps use fully balanced symmetrical circuits , what equipment do you use ?

[Ali Tait]

Balanced is +6db over SE I believe. More immune to RF too, so perhaps a lower noise floor is allowing more low level detail through.

[tom]

I started using balanced equipment when I got some ATC active speakers which seem to prefer balanced connections.
My audio research phono stage sounded much better when using the balanced out connections rather than the SE ones. As mentioned earlier balanced usually provides a higher output voltage.

[brucew268]

Classe Audio Model 30 preamp & Model 70 amp

[jandl100]

I seem to find that balanced sounds vaguer and less well defined than SE connections.

I may be imagining it, though!

I try balanced/XLR cables every now and then - but always end up going back to RCA.

[Reffc]

Balanced was primarily designed for studio use where the literally 100's of metres of cabling was prone to picking up noise (EMI/RFI etc etc) and ground loops are a very real problem.

It became fashionable in hifi in the 1980's I guess because of the common mode noise rejection advantages and in true balanced circuits, being less susceptible to ground loop hum.

However, there is a misconception that one is better than the other and this is simply not the case. Single ended has the advantages of simpler circuit path (the short wire principle) so in theory anyway should be the choice for "better" sound. However, it's Achilles heal is the phono connector. Many connectors really are very poorly designed/made and this can (and does) make quite a difference to sound. As mentioned above, SE also gives away around 6dB so to do a fair comparison, careful level matching is in order.

Balanced has the advantage of lower noise floor and a better electrical connection but the disadvantage of a more convoluted signal path and more expense in manufacturing.

A well engineered SE amp (for example) is more than capable of true high end performance as is a well engineered balanced amp. One is not better than the other as far as hifi goes but different manufacturers may have paid closer attention to one circuit or the other where both are available on a component, so one, whilst not an afterthought, can certainly be better than the other. I've heard amps with both circuits, and on some amps, the SE is by far the better connection to use whilst on others, balanced has been the way to go.

It depends on your set up. If you don' have long cable runs and EMI/RFI isn't a particular problem, then SE is more than good enough for the best high fidelity system. Ancillaries including RCA connectors are important, which is why (for example) I've gone to great pains in trying dozens of connectors and only offering what I believe to be the better ones for my reference Cables. There are many more that do a decent job but this opens up a whole new thread!

[Wakefield Turntables]

I started using balanced equipment when I got some ATC active speakers which seem to prefer balanced connections.
My audio research phono stage sounded much better when using the balanced out connections rather than the SE ones. As mentioned earlier balanced usually provides a higher output voltage.

Active atc speakers only take xlr, well my atc50 asl does anyway.

[Spectral Morn]

Someone was reminding me that most “balanced” amplifiers are actually single-ended with some added circuitry to balance the signal. Since I’ve run balanced for the last few years preamp>amp and also source>preamp, it seemed reasonable to try SE again, following the idea that simpler circuits are better for sound.

In my system that did not at all turn out to be the case! The balanced route had significantly more realistic piano and cymbals, harmonics, textures, inner detail, bass pitch, with better sound stage depth and 3D sense.

So why would that be? I first thought it might be the choice of interconnect that I was using in the SE config. But then I used the same interconnect in a balanced termination and found that was not even a little bit of the cause.

So either the opamps and extra circuitry in the balanced config produce better sound than the subset SE circuit… or the noise rejection capabilities of balanced interconnects reveals how much RFI I have behind that equipment rack!

Any other ideas?

A fully balanced design is dual differential which means separate left and right channel, so much more than just 'some' extra circuitry, in fact a complete doubling even in some cases down to separate left and right channel power supplies. Those items fitted with XLRs but are not actually balanced then there is no advantage and often the item will sound better connected via RCAs but in most cases a true balanced design if it has RCA fitted will sound better hooked up to other balanced designs, via the XLRs rather than RCAs. That has been my experience to date so far.


Regards Neil

[lurcher]

I fail to see how the first


A fully balanced design is dual differential

Requires or implies the second


which means separate left and right channel

A fully balanced design is differential yes, but it says nothing about channels or power supplies. You could have a mono balanced design, you could have a 48 channel balanced design with shared power supplies or not.

There are a couple of obvious places where balanced can be useful. Phono cartridges are in effect balanced, and are only imbalanced by connecting on pin to ground, if rewired to be floating and going into a proper balanced input phono stage the noise cancelling aspect can be of real use. Also, a balanced input to a push pull amp makes a lot of sense (especially valve) where the phase splitter is often the major sonic problem, balanced input removes the need of a phase splitter, or at least places it elsewhere.

[Spectral Morn]

I fail to see how the first



Requires or implies the second



A fully balanced design is differential yes, but it says nothing about channels or power supplies. You could have a mono balanced design, you could have a 48 channel balanced design with shared power supplies or not.

There are a couple of obvious places where balanced can be useful. Phono cartridges are in effect balanced, and are only imbalanced by connecting on pin to ground, if rewired to be floating and going into a proper balanced input phono stage the noise cancelling aspect can be of real use. Also, a balanced input to a push pull amp makes a lot of sense (especially valve) where the phase splitter is often the major sonic problem, balanced input removes the need of a phase splitter, or at least places it elsewhere.

Wrong use of words re channel

Regards Neil

[SteveTheShadow]

I am, at the moment, running a fully balanced push pull valve amplifier, I built myself, using 6AQ5 7 pin miniature output pentodes, strapped as triodes.No phase splitter as it takes a balanced signal from my M1 DAC, which has balanced XLR outputs.


Sounds lovely

[daytona600]

this thread will have legs

[walpurgis]

I don't care. Some of my amps offer both and I can't hear any difference!

[Rothchild]

On a generally related note, most balanced studio gear runs with different nominal gain and headroom than unbalanced gear (+4dBu vs -10dBV) there's a nice primer here with some tips about using the two together: http://harmoniccycle.com/harmonicweb/music-26-+4dBu-10dBV.htm

[Yomanze]

It makes a positive difference with fully balanced gear, as it is optimised with balanced operation in mind - as you are effectively doubling up on components this should be put to good use! My Krell KRC-3 is a good example of this. This isn't to say that there isn't single ended gear that sounds better! Another consideration is that RCA cables are much more audible than XLR in the audio chain.

[realysm42]

Another consideration is that RCA cables are much more audible than XLR in the audio chain.

What do you mean by this?

[Yomanze]

What do you mean by this?

Good morning, I meant that RCA interconnects make more of a difference to the sound whereas XLR is pretty much transparent. Interestingly LFD don't even make XLR cables anymore, and LFD were cable believers before most...

[Reffc]

Good morning, I meant that RCA interconnects make more of a difference to the sound whereas XLR is pretty much transparent. Interestingly LFD don't even make XLR cables anymore, and LFD were cable believers before most...

In some ways...yes; in some ways...no!

SE IC cables need to be screened for best performance otherwise they are susceptible to induced noise from EMI/RFI; the plugs make a difference too, as the materials, whether screened or not, tolerances and design can/do all have an effect on the signal. I've gone through skip loads of connectors trying to determine which "sound" best with the cables that I use, and whilst measurements can tell us some things, clearly we're not measuring the right things because there is a clear and audible difference between different types of connectors. Whether the cable itself sounds different depends entirely on the circuit it's used in, external influences, geometry and materials. SE IC's need to be more accurately made IMHO, and digital cables especially so in terms of impedance (consistency along cable length). Balanced XLR leads may be less susceptible to external influences but I have found differences in sound between them. Slight, but there.

[realysm42]

I originally used cardas neutral xlrs, then moved up to tq black, then mcru ultimate xlrs; there was a clearly audible difference between them all; id imagine even more so now my systems that much more transparent than that time.

[anthonyTD]

:):thumbsup:
I fail to see how the first



Requires or implies the second



A fully balanced design is differential yes, but it says nothing about channels or power supplies. You could have a mono balanced design, you could have a 48 channel balanced design with shared power supplies or not.

There are a couple of obvious places where balanced can be useful. Phono cartridges are in effect balanced, and are only imbalanced by connecting on pin to ground, if rewired to be floating and going into a proper balanced input phono stage the noise cancelling aspect can be of real use. Also, a balanced input to a push pull amp makes a lot of sense (especially valve) where the phase splitter is often the major sonic problem, balanced input removes the need of a phase splitter, or at least places it elsewhere.

[Bluedroog]

I have a couple of questions for those with some technical knowledge in this area as I have to say mine is virtually none. XLR cables usually are balanced but not necessarily, is that correct? The reason I ask is because I quite fancy trying My Croft 25 in to a pair of actives which often seem to have XLR in only. My assumption on the XLR usually but not necessarily being balanced is the fact you can get RCA to XLR cables. So that would be one option, no problems I should be aware of? Second would it be plausible and cost effective to mod a pre to accommodated XLR out, or is that ridiculous? Thanks.

[Barry]

If your preamp is fitted with RCA outputs, then they are unbalanced and replacing them with XLR connectors won't make them balanced. If you want the output to be balanced then you will have to fit appropriate transformers, or replace your current preamp with one that has a balanced output.

However, I would check out the specification of your active speakers - although they may be fitted with XLR connectors, the input configuration may be unbalanced; in which case you can use a (long ?) pair of RCA to XLR cables.

[anthonyTD]

Hi, All,
you can use a single ended output with some pieces of equipment that normally require a balanced input, however, for the balanced line equipment to work, it would have to have one of its normally floating signal wires reffrenced to signal earth, this would then configure the piece of equipment that was originally balanced line' into a single ended mode, as far as the front end signal circuitry is concerned.
However' as others have said, some equipment is fully differential, all the way through.
If you prefer XLR plugs over RCA/Phono plugs and sockets then you can use XLR plugs and sockets with single ended signal, you just don't use all three pins...
Hope this helps.
A...

[Rothchild]

Some useful pointers on connecting balanced and unbalanced gear, as well as how to make a 'pseudo balanced' cable:

http://www.soundonsound.com/sos/may13/articles/qanda-0513-3.htm