What are "true" balanced connectors

Sorry stereo5!

I also need to thank you for giving me a clear and direct answer to my original question!

@erik_squires 

 Each signal is actually referrenced to ground,

Not universally true.

 
I should have said referenced to -signal- ground. That is the balance point that both signals share in common. 

Sleepwalker:

Balanced signals used to be transmitted by transformer outputs and inputs which were galvanically isolated.

Best,
E

Balanced means that the + and - amplitudes of the signal are referenced equally to ground.

Balanced means that the + and - amplitudes of the signal are referenced equally to ground. 

Not a requirement when using transformers which are not center tapped, as was the case for many decades. In the old days, you'd use a single amplifier output, to drive one side of a transformer, and the resulting output had no reference to ground, only to each other.

It is only in modern times that we can use multiple op amp stages as the sender and receiver. And still, the receiver does not rely on any ground reference.

Best,
E