Audio project, ground loop question

Thread Starter

subXero

Joined Jul 29, 2009
4
Hello,

So here is a break down, I put together an audio system for research was not getting enough output from my speakers, so purchased an amp, and power supply to run the amp and presto good output and lots of noise.

I know DC power supplies can introduce a fair amount of noise into the signal and that is a possible source of my problem, but overlooking that for the moment and getting to my main question about a ground scheme.

So even if the power supply it's self is my main problem i still believe i have a ground loop and want to try and get my set up to a single point ground but need clarification on a few points.

1) basic run down of set up

PC with NI PCI card provides 2 signals to amp via BNC cables
PC is grounded via 3 prong plug to outlet

DC power supply powers car audio amp, positive terminal of PS to +12v on amp and neutral to the GND on the amp
PS grounded via 3 prong plug to outlet

From amp, speakers wires run to 2 speakers. amp grounded to PS neutral

OK,
The neutral of the power supply is likely grounded to its case and then run to earth via plug....right?

PC case grounded to earth via plug, (all BNC cables grounded to case and amp,

amp grounded to neutral of PS, (BNC's grounded to amp & PC)

So here are the questions,

Is neutral the same as ground on the DC PS, I know the neutral lead comes out of the center of the transformer but pretty sure it is the ground?

Could I eliminate plug grounds then take all case grounds to a star ground, then take star ground to earth?

Is there a better way?

And info greatly appreciated.

Thanks in advance
 

Thread Starter

subXero

Joined Jul 29, 2009
4
arc audio mini 125.4, only amp i could find with a frequency range up to 50khz which is important for our system.
 

Thread Starter

subXero

Joined Jul 29, 2009
4
PS is a pyramid 46kx, i know the noise on it is bad but like i said in the post, taking it one step at a time, looking to fix a possible ground loop before i replace the PS.
 

flat5

Joined Nov 13, 2008
403
You might use an ohm meter to verify your assumptions about the grounding. Get those questions out of the way.
Exactly what noise do you hear? Care to provide an mp3 if hard to describe?
 
Last edited:

Thread Starter

subXero

Joined Jul 29, 2009
4
Noise is not in human audible range and is picked up by sensitive microphone from speakers and seen on software. But yeah, definitely need to meter some stuff and get things worked out.
 
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