Balanced versus single ended

Why True Balance Operation?

Here is a good article on the subject. See below

Mike

http://www.atma-sphere.com/en/resource-why-balanced.html

@holmz To be clear, black is the only color you get...

I meant, “to be clear”… as a lack of noise.

(they make the mogami in brown, but black may be used to describe quietness.)

If audio components are "truly"  built to the AES balanced standard then there is minimal to no sonic differences heard with various balanced cable regardless of their cost or claims. 

My components say they are balanced, but how does one really know if they are built to the AES standard? I have never seen this mentioned in the specs.

@zlone,

My components say they are balanced, but how does one really know if they are built to the AES standard? I have never seen this mentioned in the specs.

Call the manufacturer and ask if their audio components are AES48 compliant.

Mike

With those who report here they have fully balanced audio systems input to output and yet they hear very distinct differences among balanced cable brand/models. Are there alternative or proprietary balanced audio circuits by these manufacturers or are they not true balanced circuits? 

Is this due to balance audio via use of  transformers or deviating  fully differential circuit approaches?

@charles1dad You can have a fully differential balanced preamp that does not support the balanced standard. In tube preamps this is common because coupling caps are used at the output. That coupling cap is usually part of a cathode follower circuit, and a cathode follower produces its output with respect to ground.

So that means you have two cathode followers, one for each phase, each referencing ground. The nice thing about this is that one of those can be employed as a single-ended output, so seeing RCAs and XLRs on such preamps is common. When two independent outputs are used like this, Common Mode Rejection Ratio is reduced in the system- it can never be truly balanced.

The balanced standard ignores ground, IOW the output of a device that supports AES48 does not generate either phase with respect to ground. Usually the way to do this is with an output transformer, whose secondary is connected to pin 2 and pin 3 of the XLR output and nothing else.

We patented an method of getting doing this without an output transformer, because as you know, we're the OTL guys. IOW you can support AES48 by using a Circlotron output, which is at the core of both of our patents in this area. It is possible to use semiconductors to support the standard.

One clue that the standard is supported is the 6dB issue- if the volume increases 6dB when running the preamp balanced as opposed to single-ended, that means it does not support the standard. The reason why is explained in the first paragraph above.

I think there is the idea that a transformer is a Bad Idea and so most high end audio manufacturers avoid using them (Backert Labs is an example of one that uses a transformer so they gear supports the standard). So as you point out, you get really variable results and people hear all kinds of differences in cables that simply shouldn't be there.

If the manufacturer supports AES48 they should say that- if not, ask them. If they don't know the answer, then they probably do not 😉