Earth (isolated) ground vs. wall outlet ground.

Looking on my 200amp main panel I notice that the neutral (white) wire bus and the ground (bare copper) bus have continuity. Wouldn’t it be better if my interconnected rig had it’s own earth ground thereby isolating it from feedback from the neutral wires? If not (NEC rules, Ott’s Grounding Myths, etc.) why is there a ground lug on some of my pieces? Surely it’s not there for decoration. I can’t imagine a manufacturer adding a useless item (adding cost) in a hidden place if it didn’t have specific function.  All my pieces are connected by balanced XLRs (except the speakers) and the balanced XLR has unified grounds. Inquiring (and in my case sometimes simple) minds what to know.....


128x128Ag insider logo xs@2xyesiam_a_pirate

Puritan Audio offers a product Ground Master that requires adding a seperate ground rod that connects direct to the Puritian PSM156 power conditioner. They say it is safe, any thoughts?

Post removed 

@yesiam_a_pirate Let me reflect on my radio broadcast engineering days: If our studios (and offices) were co-located at a transmitter site, with a broadcast tower (i.e., a giant lightning rod in the sky) on the property; we mainly grounded audio equipment and broadcast equipment to reduce or eliminate lightning damage. 99% of the time this also helped in reducing hum when connecting numerous studios full of audio equipment together with each other. Many times broadcast audio equipment also had *this* grounding lug on the rear chasis panel. Now if you had a professionally built broadcast facility; you typically had a 3" copper ground strap running between all studios; which terminated at the broadcast tower's ground system (or if you didn't have a co-located transmitter or tower, the ground was tied to the building's star ground system). When that 3" ground strap was available, each equipment chasis ground lug was tied to this ground strap (along with plugging the 3 prong AC plug in the wall for power). If lightning struck the tower, this ground strap provided an extremely low impedance ground, but more importantly it kept all equipment connected to it at the same low impedance ground potential. I still employ much of what I learned and used at broadcast facilities on my home audio and grounding system. The result is extremely low noise floors. 

To lift or not lift the pin 1 connection on an analog XLR connector is another topic related to grounding. In a broadcast facility it's almost impossible to control this issue with sometimes hundreds of XLR connections taking place (in the good ol' analog days), but since most radio stations had decent star ground systems incorporated, this most times wasn't a problem. Now almost all radio stations are wired digitally, eliminating a lot of ground loop problems. Again, this same scheme can be incorporated into home audio systems with numerous pieces of balanced analog gear interconnected. IMO it's much easier to control this in a home environment as compared to a radio station environment. Learning how to solder can be a very important skill to know when setting up a home audio system, as you'll want to be able to unsolder or solder, some of these pin 1 XLR connections when hum presents itself.   


”No. It’s almost certain to violate your local electrical code. It is to ensure that circuit breakers trips when they have to. Grounding your electrical system to more than one location can cause breakers not to trip during a fault.”

This is absolutely, 100%, correct.

Do not add a separated ground to the system. In the event of fault, the circuit breaker will be bypassed by the new route to ground, stay open, and either start a fire or cause a shock.

If you chose to use the ground lugs on your equipment, the  should go to the plug where you have everything plugged in.  You could have one lead off the screw on the plug  and then a bolt nut and washer tying all your spades grounds together.  This is called a “star ground”.


if you are worried about communication between the components, don’t be.  Everything will take the lazy path the ground.  Not sideways.


but if you are going to buy a fancy box, be advised they are literally what I just described and a handful of diodes (which allow current flow in one direction).  Maybe $50 of parts.

Puritan Audio offers a product Ground Master that requires adding a seperate ground rod that connects direct to the Puritian PSM156 power conditioner. They say it is safe, any thoughts?

’Yikes!’ is a thought...