Balanced or Unbalanced?

Lupinthe3rd and Dave, balanced lines have been shown to be an advantage when the interconnect length is only 6 inches. Their advantages are not based on length, although that **is** an advantage that they have. The real advantage is that the balanced line system was created with the specific intent (which it does very successfully) of eliminating interconnect cable differences and artifacts, in essence, to eliminate anything about the cable that makes it audible in a system.

Another way of looking at this is: if you ever had to audition a cable to see if it sounded right in your system, than you already know what the balanced line system is for and why it can be useful for yourself.

Atmasphere, I did audition balanced vs. balanced of the same brand and model and they sounded the same in my system, but both sounded different from the model that they replaced. So, I don't see how the sound of the interconnect was removed by going balanced. If that were true, then every balanced IC would sound the same, yet they don't.

Dave

I'm not even sure what is balanced and what isn't there days. Krell advertises the 400xi as being fully balanced yet the model up FBI is a 'true' fully balanced design, while the 400xi only offers Balanced Circuitry. I think the industry has somewhat sneered at the claims of some manufactures and have more or less put the 'balanced' claim within the wattage category of 'friendly Grey marketing'.

No offense to the balanced proponents, but there seems to me to be an aspect that is not often discussed about balanced systems. To be truly balanced, you must have the equivalent of two systems, which are then compared to each other in some way (subtraction, division, etc.) to provide the output. If either of these systems changes once they are initially calibrated, problems may result. In addition, you are now talking about twice as many components which can add their own unique signature, as well as drift in value as they age.
As an analytical chemist by trade, my analogy is a dual-beam optical system for a spectrometer: instead of simply having a single beam of light which is used to interrogate a sample and determine its chemical composition (a single beam system), sometimes it is preferable to use a dual-beam system; the light from the source is split into two beams, a reference beam and a sample beam. The reference beam passes through blank sample (water for example) while the sample beam passes through a solution of the sample. The spectrometer then subtracts the spectrum of the reference beam from that of the sample beam to provide the corrected spectrum. This type of system is excellent at correcting for errors due to background in the solvents or drift of the optical source.
It is not always the case that a dual beam system is preferable for your analysis. A dual beam system can subtract the influences of a blank automatically, but that blank is not contained in the same vessel (cuvette in chemistry terms) as the sample, and the reference optical path is not the same as the sample optical path. Also, as mentioned above, the dual path can create problems when components age differently.
So to me the argument is not as cut and dry as it may seem at first. If you do not need the error correction afforded by a duplication of component paths, perhaps you are better off without it, as it may introduce unnecessary complication and expense to the system.

To add to my previous post (too quick on the submit button), an additional disadvantage of dual beam systems is that you halve the power of your source to create the twin beams - in some cases that creates an unacceptable loss in sensitivity to low level components. Is there a direct analogy of this phenomenon in audio systems?