Balanced interconnection and ground

[Geert]

That's in line with the diagram I posted above. For low frequencies your connection is like floating at both ends. Insufficient shielding against mains frequency. Input pin 1 to ground will work in this case since the source is floating (as long as you don't connected other unbalanced sources to the Yamaha).

 

[GXAlan]

That's in line with the diagram I posted above. For low frequencies your connection is like floating at both ends. Insufficient shielding against mains frequency. Input pin 1 to ground will work in this case since the source is floating (as long as you don't connected other unbalanced sources to the Yamaha).

Got it. What is the benefit of grounding the amp versus just connecting the ground lug of the Yamaha to the Earth ground so that both the amp and source share the same earth ground?

 

[Geert]

Connecting the source end to ground creates a ground loop, theoretically and in this case only for high frequencies so it won't matter. If you don't experience any audible issues, then it's fine as it is.

 

[Sokel]

Looking at the Meyer Sound Amie manual:

View attachment 343530

Are you sure that the internal connection of your cable is connected to XRL's casing (the forth upper pin) ?
A lot of them don't.

 

[nagster]

My Yamaha CX-A5100 (two prong power) via XLR to my Meyer Sound Amie (three prong power) generates a ground loop that’s audible and annoying even though it’s a presumably a proper balanced connection as both companies make PA gear.My Yamaha CX-A5100 (two prong power) via XLR to my Meyer Sound Amie (three prong power) generates a ground loop that’s audible and annoying even though it’s a presumably a proper balanced connection as both companies make PA gear.

I can remove the hum by taking the phono lug of the Yamaha to the ground lug of my line conditioner. The ground lug of my line conditioner is attached to earth safety ground.

Ideas? I have tried a few XLR cables. It’s not a big deal to use the grounding wire, but I am curious. Panamax, Belkin, Monster Power all have ground lugs on their power conditioners (with Panamax being the only one still making power conditioners)

When connecting XLR cables with floating shells to Meyer Sound powered speakers, noise will often occur.
One easy solution is to short the speaker's XLR terminal shell and pin 1. I have several Image plugs, and if I don't have time, I plug them into the loop out terminals of speakers.

 

[ldarieut]

I use these:

https://www.neutrik.com/en/neutrik/products/xlr-connectors/xlr-chassis-connectors/a-series?c=audio

and more precisely, this one:
Female connector
-1 = mating connector shell to pin1 and front panel

This way, I never had ground loop issue: pin1 connects to the shell and the chassis with the metal screw.

Using these:

https://www.neutrik.com/en/neutrik/products/xlr-connectors/xlr-chassis-connectors/d-series?c=audio

You have to solder a tiny wire from pin 1 to the ground latch, which is connected to the shell that connects to the chassis. If you don't do this, you will probably hear a hum.
Worst case is when you do only half of the above: better not ground your XLR socket at all, than doing half the job.