XPA-DR3 "Balanced Output Do Not Ground" What does this mean?

[lukewayne]

Hi, Just getting ready to hook up my new XPA-DR3 and I noticed this warning on the back:





I didn't see anything in the manual about what this means, and I've never seen something like that before (that I remember)

I have run seperate grounds for each circuit in my equipment rack, but I had intended on tying all of the chassis grounds together with a grounding bar in the rack. Is this a bad idea?

Thanks for any insight.

[leonski]

With everything UNPLUGGED and all caps discharged......wait a couple days, just to be sure,
for MOST amps, the Negative (-) speaker terminal will be THE SAME as Earth Ground or Chasis Ground.
With a meter, the negative speaker output should be the same potential on BOTH speaker outputs.  And measure nearly ZERO ohms.....between them.
That is not the case in a balanced amp....

In a blanced amp, BOTH the Negative and Positive terminals 'float' and are NOT connected to ground.   OR each other in any way.

This has ramifications. I don't think it would be a good idea, for example to hook a balanced output amp VIA SPEAKER WIRES to a sub. Sub will be a common ground setup and ZAP....There She Goes!
You can't hook up an amp like this to an origianl DynaQuad system either. I'll let you look that one up!

I think this is good information, but IF one of the design guys has an input?    Please note where I went off the rails.  

[petew]

Jan 6, 2019 0:24:29 GMT -5 lukewayne said:

...I have run seperate grounds for each circuit in my equipment rack, but I had intended on tying all of the chassis grounds together with a grounding bar in the rack. Is this a bad idea?...

This warning just means to not ground the amplifier output. Something like an in-wall volume control or external speaker switcher may have a common ground setup, which would be bad with a balanced amp.

I don't have an opinion on grounding equipment, other than using the three wire cord provided and being sure that your ac wiring is up to snuff.

[lukewayne]

Jan 6, 2019 11:13:22 GMT -5 petew said:

Jan 6, 2019 0:24:29 GMT -5 lukewayne said:

...I have run seperate grounds for each circuit in my equipment rack, but I had intended on tying all of the chassis grounds together with a grounding bar in the rack. Is this a bad idea?...

This warning just means to not ground the amplifier output. Something like an in-wall volume control or external speaker switcher may have a common ground setup, which would be bad with a balanced amp.

I don't have an opinion on grounding equipment, other than using the three wire cord provided and being sure that your ac wiring is up to snuff.

OK Thanks! My outputs are going straight to speakers, so nothing to worry about then.

AC wiring is up to snuff for sure, it's all brand new.

FYI the amps actually have a two wire cord, which is why I thought the note might be referring to grounding the unit.

[lukewayne]

Jan 6, 2019 1:56:39 GMT -5 leonski said:

With everything UNPLUGGED and all caps discharged......wait a couple days, just to be sure,
for MOST amps, the Negative (-) speaker terminal will be THE SAME as Earth Ground or Chasis Ground.
With a meter, the negative speaker output should be the same potential on BOTH speaker outputs.  And measure nearly ZERO ohms.....between them.
That is not the case in a balanced amp....

In a blanced amp, BOTH the Negative and Positive terminals 'float' and are NOT connected to ground.   OR each other in any way.

This has ramifications. I don't think it would be a good idea, for example to hook a balanced output amp VIA SPEAKER WIRES to a sub. Sub will be a common ground setup and ZAP....There She Goes!
You can't hook up an amp like this to an origianl DynaQuad system either. I'll let you look that one up!

I think this is good information, but IF one of the design guys has an input?    Please note where I went off the rails.  

interesting. thanks for the explination

[leonski]

Maybe this artricle from PSAudio will help?

www.psaudio.com/ps_how/how-to-practice-best-grounding/