Balanced: 180 ͦinverse of signal. How? Or rather where?

[Paul R Johnson]

Just to confuse - while modern audio gear uses 3 conductors for balanced operation, one is actually not too important - ground. As long as you don't wish to use phantom power, just connecting pins 2 and 3 both ends works perfectly well - just losing the screening. If the discussion took a bit of time get settled in, this might be a touch too much - but loudspeaker connections could be considered balanced, mains electricity too, and until it gets to the switches and pots - even guitar pickups start off balanced!

[Richard Crowley]

Originally Posted by Paul R Johnson

Just to confuse - while modern audio gear uses 3 conductors for balanced operation, one is actually not too important - ground. As long as you don't wish to use phantom power, just connecting pins 2 and 3 both ends works perfectly well - just losing the screening. If the discussion took a bit of time get settled in, this might be a touch too much - but...

Yes, that is why I qualified my statement with "common, modern usage". Unshielded pair are actually coming back into fashion 100 years after the telephone industry standardized on them for POTS (Plain Old Telephone Service). I recently used ordinary Cat5 UTP (Unshielded Twisted Pair) to extend the Direct Outputs from a large mixing console over 100 feet to a recording mixer line inputs. 36 channels work great even though the source is only "impedance balanced" and not true balanced.

loudspeaker connections could be considered balanced, mains electricity too,

Sort of. The destination/load is typically "balanced" because it isn't ground-reference. But the source typically has one side grounded.

and until it gets to the switches and pots - even guitar pickups start off balanced!

And the main problem with instrument connections is that they continue to use the outdated and deadly standard of high-impedance, unbalanced. :-(

[Rick Reineke]

"one is actually not too important - ground."
Yes, except for mic cables. It's common practice in recording studio wiring to only connect ground to one end of balanced interconnect audio cables for the outboard gear, consoles and patch bays, ect. In fact, I worked in a studio and when we did a renovation/rebuild, even the AC grounds on most of the gear was lifted, of course the gear chassis were positively and securely grounded to only one source. In this case, a 8-10 foot copper rod into the earth. A 'star' grounding system, as I recall.
Another studio I worked at, had balanced AC power transformers.. it was very expensive, but it was a multi-million $ facility.. even the EMI prone single-coil Strat pick-ups were quiet.
Of course a lot of this not necessary these days with no outboard gear and everything's done 'in-the-box'.