[Scott Ramsay]

I’m glad you cleared up the definition of a balanced circuit, Bill.
But there is another aspect of the terminology that needs to be corrected.

A cable with TRS plugs should not be called a ‘balanced’ cable. It is a 3 conductor cable, but as Bill has pointed out, a circuit is not balanced unless it is plugged into gear that does the balancing.

Sometimes, TRS cables are used as ‘send and return’ cables on older mixers. So this configuration is also not ‘balanced’.

And, as everyone knows, headphone plugs are also TRS- but the connection is not ‘balanced’ because it is being used to carry a stereo signal- one conductor for the L, one conductor for the R.

It is true that with an XLR connector, the gear (mixer) you will plug into will almost always automatically be balanced because it is meant as a microphone input. But there are examples of XLR cables also being used for other purposes that are not balanced.