balanced connection, better than single ended?


If you have gear that can do balanced & unbalanced connections which is preferable and why? I have read that balanced connections are better for long runs of cable otherwise a single ended connections are fine but not sure of this since I have yet to use this sort of connection. Also I read that some gear is not truly balanced in their circuitry thus this gear may not benefit from a balanced connection. I ask only because I'm recently buying an amp that has true balanced circuitry but now must find a preamp of the same.
phd
Roscoeiii, I'm not sure I understand your question... I have used transformers at the output of single-ended preamps to enable them to drive very long cables, which by default have to be balanced. You can't do it with a simple adapter though, you have to use a transformer or active circuit.

Sometimes I run into cases where I want to run a balanced preamp with a single-ended amplifier. It turns out that there is a simple mod that can be performed on most amps with single-ended inputs that will allow them accept the balanced input in the balanced domain- without input transformers. You can even do this with SET amplifiers.

Now I regard the use of transformers or active circuits to convert from one domain to the other as a degradation, so if faced with a preamp that is single-ended out, I would try to find some way to use it with the balanced input amp directly (using a short SE cable) rather than do a conversion, as most balanced amps will accept a single-ended input quite well.
Some such as Rowland Research claim balancing transformers perform better than differentially balanced circuits and simply use Jensen Transformers to attain a balanced output. Audio Research has also done the same thing with some of their preamps and line stages. Audio Research's Ref Phono Stage is an example. Anyone with a little know how can add Jensen's balancing transformers to a components outputs.
Atmasphere,

Are there any cases in which you would recommend an RCA to balanced conversion to convert single-ended outputs to balanced inputs?

Only to run long balanced cables?

For differential amps?
I did own the ARC VT-100 and thought it sounded better using the RCA inputs. The only balanced preamp I had (Sonic Frontiers) was not really that great anyway and the "single ended" preamp (ARC LS3) was really much better sounding anyway , imo, in my system. So, there are so many more factors that just "bal" - vs -"se".

I also tried running a Wadia CD player direct into the VT100 using the XLRs and I just dont think the two liked each other? I thought it may be causeing more than just a sonic mismatch problem.
do you imply that any sonic effect of cable capacitance, inductance and other electrical characteristics effecting the single ended cable sound - vanish? Gone? Diminished?

Yes, either gone entirely or dramatically diminished. IME 'gone' is a lot closer than 'diminished'.

Spectron is right that some differential amps will sound better with a balanced input. But- if the amp is properly designed, really the only difference that will be heard will be that the single ended source, plugged into such an amp, will sound inferior due to the cable artifact.
Hello Arthmaspere.

" The raison d'etre of balanced line is to be able to use any balanced cable cable of any length (or cost) and have that cable have zero sonic artifact. So it does not matter the length (nor price); there is always an advantage to balanced lines."

By saying that "...that [balanced] cable have zero sonic artifact" do you imply that any sonic effect of cable capacitance, inductance and other electrical characteristics effecting the single ended cable sound - vanish? Gone? Diminished?

I would much appreciate if you can expand on this very interesting statement

Next point: Spectron wrote:

"I must state for the record that some (e.g. differential) balanced amplifiers will still utilize your single ended signal but most probably not in fullest extend - it can be debated."

and indeed you debate it - which is absolutely fine and even great! However, it confirms Spectron strong recommendation:

".... You got to speak with manufacturer of your equipment to untilize it in FULL."

Indeed, there are so many ideas, designs, technologies, ways of implementation that its almost a must.

Thank you !
The raison d'etre of balanced line is to be able to use any balanced cable cable of any length (or cost) and have that cable have zero sonic artifact. So it does not matter the length (nor price); there is always an advantage to balanced lines.

In order to achieve that, the balanced line standard requires a low output impedance of its sources. This is poorly understood by the (IMO) majority of high end audio manufacturers, who often seem to regard balanced lines as trendy rather than the serious sonic boon that it is. As a result many high end audio products do not handle balanced signals nearly as well as they should, leading to varible results. This is why you see this question come up time and again on these forums!

A common myth is that balanced circuits require twice as much circuitry. This is untrue- quite often they require **less** circuitry as you have less noise, and thus less need for as many gain stages. Also, to build a differential balanced circuit does not require double the parts of its single-ended counterpart!

Yet another myth is that there is no advantage to using a balanced circuit with a single-ended input. As pointed out by Al, you retain the advantages of the circuit, you only loose the advantage of the cable. The gain **does not** change- that is to say you do not loose 6 db, as, at least with differential circuits, the input is looking for the *difference* between the inputs, which might be 2 opposite phases, or it might be the non-inverting input and ground. The differential input does not care.
Phd,

"maybe I missed something but now I'm not sure. But I still want to see for myself".

That's the ticket. My ears are directly coupled to my pocketbook and by that I mean not going cheap, just getting some improvement for the money I spent and being aware of law of diminishing returns. That doesn't always happen when you buy theories or marketing.

I wonder what happens to a balanced preamp when the parts drift out of spec as they age. Single ended would age also but it's not relying on an identical twin aging at the same spec. I've never been able to get all 4 of the tires on my car to age at the same rate even with the rotate/balance ritual.
"The Audio Research amp that I purchased is a true balanced design.... I... never took advantage of its balanced technology"

I am not sure I understand meaning of the word "true balanced design"....as oppose to "false.."?

I guess that your ARC amp has FULLY balanced design. I define word "fully" as balanced from the beginning to the end of the signal path.

If so then you did big mistake ny not utilizing fully balanced design since you already paid for it and had it!

Lets clarify the terms confused by some audiophiles

1 - XLR termination - does not mean anytning. It could lead to "true" balanced input stage or its negative signal is immidiately grounded thus converting it into single ended input signal.

2 True balanced input. Can utilize the number of connections. E. G. one XLR or as its done on Spectron amps (as an option to use) two RCA inputs (one positive and another is negative) - I use it in my own system.

Its advantage is described above - reduction of noise upstream. Nothing more ! I have tube preamp (Joule-Electra LA-300ME) with RCA outputs and when I place my ear to the woofer of my speaker I hear nothing, no noise, nothing...so for me and many, many, many others balanced input provide nothing. (again if you have 100' cable and its raining and stars allign badly etc then you better off with balanced input)

3 Balanced amplification. There are a few implimentation of it. As one of them let look at Joule-Electra LA-300ME preamp. It has RCA input, then the phase splitter splits the input signal into two (positive and negative) and TWO SETS of amplification stage or stages amplify them . Next the one signal is subctracted from another (positive - negative = positive x2 - double signal or in this case double half-signal). However, please note that as oppose to the noise - distortion produced by this amplification stage or stages is not random event and therefore, in "ideal amplifier" both positive and negative distortions have identical amplitude but oppose phases and distortions are therefore CANCEL each other during subtraction stage. As a result you have distrortion free music.

Distortion-free music is spectacular !!!!!!!!

Finally, "300" outputs this already distortion free signal via RCA (single ended output).... and you do with it whatever you want

4 Fully Balanced Design where you have balanced inputs, outputs and most important (and most $$$$$$$$$$$$$) balanced amplification.

IMO, to have fully balanced amplifier and use only half of it is crazy..... You got to speak with manufacturer of your equipment to untilize it in FULL.

I must state for the record that some (e.g.differential) balanced amplifiers will still utilize your single ended signal but most probably not in fullest extend - it can be debated.

Example: Joule-Electra fully balanced preamp LA-450ME. As amplification it balanced twice i.e. has twice more stages as LA-300ME. One set remove distortions as explained above - but in real world amplifier you can't cancel them to zero, part toletance is not 100% thus another set cancel residuals and if you look J-E web site you will see that distortion level drops 8 times going from "300" to "450".

Double Distortioin Free amplifier is double spectacular !!!!

At any rate, Joule-Electra can add single ended input (RCA) and phase splitter so you will use all 450's amplification stages even if your input signal is single ended.

Hope it helps - if not my apologies
10-03-10. Phd: The Audio Research amp that I purchased is a true balanced design. But more importantly I like the way it sounds. I used to own it two years ago and never took advantage of its balanced technology but was thinking that this time I should try it in its fully balanced mode because maybe I missed something but now I'm not sure.
I could be wrong, not being familiar with the specific design, but I suspect that you were getting much of the benefit of the amp's fully balanced internal design without realizing it (contrary to some of what has been said above).

Since the amp is fully balanced internally, and provides rca as well as xlr inputs, I would expect that when the rca inputs are used there is circuitry at the front end of the amp that performs a single-ended to balanced conversion. That would allow the benefits of fully balanced INTERNAL design to be retained, at the expense of the possible sonic side-effects of the extra circuitry (which I would expect to be minimal or negligible in an ARC or other good design).

Some of those benefits, which have not yet been mentioned in this thread, are cancellation of some forms of internally generated distortion, and loading of the power supply that is more constant than with most unbalanced internal topologies (other than Class A). That in turn reduces internally generated noise, and possibly also inter-channel crosstalk in the case of a stereo amp.

Those benefits would NOT be realized, btw, in the case of a fully balanced amp that does not provide rca inputs, if a simple rca-to-xlr adapter were used at the inputs, which is an approach that would make no sense with a fully balanced amp. They WOULD be realized if something like a Jensen transformer were used to convert single-ended to balanced.

As far as the benefits of balanced EXTERNAL connection are concerned, I would add greatly reduced susceptibility to ground loop issues to what has been mentioned. That will sometimes be significant even with short cable lengths. That benefit, and also the common mode noise rejection that has been mentioned, will be realized regardless of whether the components are balanced internally or not. Although if they are not balanced internally, the possible sonic effects of the extra stage required to perform single-ended to balanced conversion may present a tradeoff.

All of those factors, of course, can be outweighed by many other variables in any given system, so I agree with the several people who have suggested experimentation and going with what sounds best. For initial experimental purposes, at least, you might want to consider purchasing a pair of inexpensive pro-oriented Mogami xlr cables.

Best regards,
-- Al
I have an all Ayre system where each component is truly balanced. There are connections as well for single ended use. I've tried both, and balanced is clearly better in this application...and not by a small degree.
Onemug, I believe your right, it would be foolish just to buy a product because it is balanced. The Audio Research amp that I purchased is a true balanced design. But more importantly I like the way it sounds. I used to own it two years ago and never took advantage of its balanced technology but was thinking that this time I should try it in its fully balanced mode because maybe I missed something but now I'm not sure. But I still want to see for myself.
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I don't necessarily think balanced sounds better except for the lower noise floor which constitutes to better audio to me. I also prefer the better connections XLR's offer.
>>> I ask only because I'm recently buying an amp that has true balanced circuitry but now must find a preamp of the same.

If you can find a "fully" balanced pre that you're happy with, that's great but I wouldn't limit myself to that only. I have a balanced amp and drove it with a balance preamp. Life was good. One day I demoed a preamp that only had rca's and it was much better than the balanced one.

Find the best preamp for your budget and don't worry if it's balanced or not. Go by the sound.
A true balanced line interconnection circuit needs to be present in both of the devices being connected in order to realize any advantage.

For many years balanced line connections were mostly used in professional applications where long cable runs were common. In a recording studio or public sound system environment, cable runs of 75', 100' or more are not uncommon. A balanced line has a much better common mode rejection of extraneous noise, so will be much quieter (less hum, hiss & other interference pickup) with long cable runs.

Balanced interconnects have become a popular option on some higher end home equipment. The trade off is the use of transformers or differential circuits which complicates things a bit. Whether this extra circuitry is worth it or not is something only a buyer can answer for himself.

You are also right there are some pieces of equipment that offer XLR interconnects but do not have true balanced circuits.

Keep in mind there are many other aspects of electronic equipment design that may make a bigger difference than this one issue. In other words, if you use typically short 1 or 2 meter interconnects commonly seen in home stereo use and hear a difference between two components, it may well be due to a factor other than a balanced vs single ended line.

My two cents is don't get caught up with this one issue. If you audition two pieces of equipment and prefer one over another, don't waste too much time worrying about assigning a reason to a particular technical detail.
Balanced or Symmetrical power is explained quite well here:

http://www.equitech.com/faq/faq.htm
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Rwwear, I wonder if that increase of 6db of volume is sometimes perceived as better sound quality?
Coolhand, what do you mean by balanced power to your equipment?

TVAD, I don't know which sounds better since I never used balanced interconnects. I have a large bag of single ended interconnects but no balanced. Looks like I will be buying a pair soon.
I prefer balanced because of the noise rejection and the 6db increase in volume doesn't hurt either.
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Indeed what you have read is correct.
There is largely no benefit to be gained from using short balanced runs in a typical hi-fi system, particularly when most, if not all of the equipment is TRULY balanced end to end in its internal design, which effectively means a doubling of component count.
What is usually far more beneficial however, is balanced POWER to your equipment.