Is A Completely Balanced Signal Path Worth It?

[aces high]

This is something that I've been contemplating for a few months now and I haven't been able to come to a conclusion on my own that satisfies my curiosity. By completely balanced I don't mean just XLR connections but a balanced differential signal path. So for instance if you started with a balanced processor such as the Anthem AVM 50 or D2v which have balanced stereo inputs and also used the Emo XPA-1's and the balanced stereo inputs of the Oppo bd 95 would it be a significant improvement over non balanced or single ended gear? This would obviously only for two channel playback and not apply to any HT applications. I know that the main benefit of using balanced components is better noise rejection and a lower noise floor. Most balanced components are significantly more expensive than their single ended non balanced counter parts. So is it really worth the extra cost?

[Big Daddy]

There is a lot of information on balanced versus unbalanced written by a tired and overworked man in https://forum.blu-ray.com/pre-pro-am...rs-thread.html. Unfortunately, not too many people bother to read it.

I copied this section from post #1 of that thread.

Fully Differential Balanced Circuit Design

Most professional audio products provide balanced inputs and outputs through XLR or TRS connectors. In almost all cases, a balanced input signal is internally converted to an unbalanced (single-ended) signal by using a transformer or amplifier. After the internal processing is finished, the signal is converted back to balanced signal and sent to an XLR/TRS output.

A very small number of professional products may exist that use balanced signal from input to output without ever converting it to unbalanced signal. This is referred to as fully differential balanced circuit design. In very critical applications (not home theater), such a design offers better signal integrity by avoiding the extra transformers or amplifiers required for unbalancing and rebalancing. It is claimed by promoters that fully balanced internal circuitry can yield 3dB of additional dynamic range. Don't believe everything that is claimed.

http://www.audioholics.com/education...-interconnects
http://www.hottconsultants.com/pdf_f...onnections.pdf
http://www.rane.com/note110.html
http://www.dplay.com/dv/balance/balance.html
http://www.montagar.com/~patj/db_db.htm

[Johnny Vinyl]

I always thought that balanced XLR connections really made no difference in very short runs (think personal audio setups).

[roar]

Originally Posted by John72953

I always thought that balanced XLR connections really made no difference in very short runs (think personal audio setups).

But the cables do give you the feeling of a much more secure connection. There a lot of things in my setup that I did pretty much only because I could and not because I think I can hear a difference. Running XLR's between my amp and processor was one of them.

[Johnny Vinyl]

Originally Posted by roar

But the cables do give you the feeling of a much more secure connection. There a lot of things in my setup that I did pretty much only because I could and not because I think I can hear a difference. Running XLR's between my amp and processor was one of them.

How do you figure that? I've never had an issue with my RCA connections coming loose?

However, like you said, if you have the ability to make XLR connections, you may as well use them.

[Big Daddy]

A balanced XLR cable has three major advantages over an unbalanced RCA cable and that is why pro users prefer them.

These are the advantages:

1. XLR connectors are more robust. They do not come loose as easily as RCA cables. Imagine in the middle of rock concert with lots of speakers, amplifiers, cables, and all the craziness, some RCA cables become loose. You will have a riot.
2. Becuase they are balanced and are grounded better, XLR cables are relatively noise free. RCA cables, on the other hand, can drive you crazy with noise and hum.
3. There is a limit on how long you can make an RCA cable (normally below 10 meters) before it significantly attenuates the signal. XLR cables can be as long as a few hundred feet.

[Johnny Vinyl]

Originally Posted by Big Daddy

A balanced XLR cable has three major advantages over an unbalanced RCA cable and that is why pro users prefer them.

These are the advantages:

1. XLR connectors are more robust. They do not come loose as easily as RCA cables. Imagine in the middle of rock concert with lots of speakers, amplifiers, cables, and all the craziness, some RCA cables become loose. You will have a riot.
2. Becuase they are balanced and are grounded better, XLR cables are relatively noise free. RCA cables, on the other hand, can drive you crazy with noise and hum.
3. There is a limit on how long you can make an RCA cable (normally below 10 meters) before it significantly attenuates the signal. XLR cables can be as long as a few hundred feet.

Just playing devil's advocate here, but isn't it true that the "noise and hum" from RCA cables really only comes into play with longer connections, which is why pros prefer XLR's?

I'm not negating the potential benefit of XLR over RCA in short runs, but I've not heard any differences at all.

[Big Daddy]

Originally Posted by John72953

Just playing devil's advocate here, but isn't it true that the "noise and hum" from RCA cables really only comes into play with longer connections, which is why pros prefer XLR's?

I'm not negating the potential benefit of XLR over RCA in short runs, but I've not heard any differences at all.

The hum and noise can affect even short cables. For example, I had a 6ft generic RCA cable from Radio shack connected to a subwoofer. Everytime I touched it by accident or moved behind the audio rack to adjust something, it would make the most horrible sound through the subwoofer. I moved the subwoofer slightly and replaced the cable with a 15ft shielded coxial cable and the problem went away.

As far as quality of interconnects is concerned, there is no difference between XLR and RCA cables below 10 meters. Once you go beyond that, signal attenuation may play a role.

[Johnny Vinyl]

Thanks Frank!

[aces high]

Unfortunately I'm not talking about just using some XLR interconnects, by a fully balanced signal path I'm referring to the components using balanced circuitry as well. Sorry if I hadn't explained myself well enough, here's an example off what I mean taken from the Oppo bd 95 product page.
XLR Balanced Stereo Output- The stereo output offers both XLR balanced and RCA single ended connectors. The balanced output features a true differential signal path all the way from the DAC to the 3 pin XLR connector. By transmitting a pair of differential signals, the balanced output provides better common mode noise rejection and improves the signal quality.
Some pre amps and processor also have a true differential balanced inputs or outputs, along with some amplifiers employing the same technology. I realize that many of these components have features and build quality that will also improve the sound but is it worth to have only balanced components coupled with the balanced interconnects?

[roar]

Originally Posted by John72953

How do you figure that? I've never had an issue with my RCA connections coming loose?

However, like you said, if you have the ability to make XLR connections, you may as well use them.

I dunno... I just kind of figured it

I have had RCA cables come loose on me when moving equipment around in tight spaces, but I haven't ever had them spontaneously come loose, so I'm not trying say RCA isn't a good connection.

I'm not sure how to describe the feeling, ummm, perhaps I feel like plugging in an XLR is more like plugging in a 220 stove outlet, as opposed to a lamp cord into a wall outlet, both get the job done and aren't going to fall out, but one is more satisfying than the other

[roar]

Originally Posted by aces high

Unfortunately I'm not talking about just using some XLR interconnects, by a fully balanced signal path I'm referring to the components using balanced circuitry as well. Sorry if I hadn't explained myself well enough, here's an example off what I mean taken from the Oppo bd 95 product page.
XLR Balanced Stereo Output- The stereo output offers both XLR balanced and RCA single ended connectors. The balanced output features a true differential signal path all the way from the DAC to the 3 pin XLR connector. By transmitting a pair of differential signals, the balanced output provides better common mode noise rejection and improves the signal quality.
Some pre amps and processor also have a true differential balanced inputs or outputs, along with some amplifiers employing the same technology. I realize that many of these components have features and build quality that will also improve the sound but is it worth to have only balanced components coupled with the balanced interconnects?

I think I understood you, I just believe unless you have trained ears or are rather musically gifted you would be super hard pressed to hear the difference... this of course is only my opnion with very limited expereince in listening to high end audio equipment. I just know that as I upgrade the different pieces in my admitly rather humble setup I hear very little difference along the way. I think if I were to do a blind test with a balanced and unbalanced connectors as the only difference in a chain of equipment I could not tell one from another. I am that confident of my untrained ears

[Big Daddy]

Originally Posted by aces high

Unfortunately I'm not talking about just using some XLR interconnects, by a fully balanced signal path I'm referring to the components using balanced circuitry as well. Sorry if I hadn't explained myself well enough, here's an example off what I mean taken from the Oppo bd 95 product page.
XLR Balanced Stereo Output- The stereo output offers both XLR balanced and RCA single ended connectors. The balanced output features a true differential signal path all the way from the DAC to the 3 pin XLR connector. By transmitting a pair of differential signals, the balanced output provides better common mode noise rejection and improves the signal quality.
Some pre amps and processor also have a true differential balanced inputs or outputs, along with some amplifiers employing the same technology. I realize that many of these components have features and build quality that will also improve the sound but is it worth to have only balanced components coupled with the balanced interconnects?

I believe I answered you in post #2. Did you read it?

[aces high]

Originally Posted by Big Daddy

I believe I answered you in post #2. Did you read it?

Obviously not closely enough. Thanks Big Daddy.

[HT in Paradise]

There is another very important aspect in relation to the subject that has been ignored, that of balanced AC. To my understanding, a fully balanced system must also entail balanced AC. In such a system (with balanced AC and all audio components) everything is thus balanced from input to output and there is a huge difference. A US company called Equi=tech pioneered balanced AC technology you can do a google search for more info.

I run a form of balanced power on some of my HT system components that allow for it, in the form of natural transformerless +110V and -110V that combine resulting in 220V balanced. Equi=tech manufactures tranformers that combine balanced 60V pos. and neg. to produce balanced 120V, or for Europeans a 220V transformer too. Either balanced AC system produces sublime noiseless audio and in some cases higher definition video too.

I imagine you could also PM a few of the other forum members that own Equi=tech transformers for their personal experience.

Cheers.

HTinP