Safety Ground Q

I think @cleeds brings up a good point by accident.

The reason ground loops in audio gear happens is probably due to historical oversight.

Stereo appliances went from being all in one units without grounds to separates with a separate chassis ground and, at least for unbalanced signals (using RCA) , never quite reconciled the difference between a signal ground and safety ground.

This article may help.  Apparently ground pins started appearing in 1967.  For some reason people still think of Neutral and Ground as equivalent but don't ask, if they are the same thing why are they on separate pins and conductors?

https://www.howtolookatahouse.com/Blog/Entries/2018/7/when-were-grounded-three-slot-receptacle-outlets-first-required.html

erik_squires

For some reason people still think of Neutral and Ground as equivalent but don't ask, if they are the same thing why are they on separate pins and conductors?

If nothing else, they are tied together at the service panel.

Good discussion.  

I'll add something that is somewhat obvious but some may not understand it:  Neutral and ground, being tied together at the panel, will both "work" to run a piece of equipment.  So if something is wired wrong, there may be no indication until something shorts.   Also you might get a bit of a tingle touching the frame which would indicate a problem.

And in Audio Equipment, you can get a noisy ground loop. 

Jerry