[sdiy] Why dual grounds?

[Andre Majorel]

On 2010-06-09 23:10 +0200, David G. Dixon wrote:

> > On Oakley boards, all signal and power ground traces go to the
> > ground pin that's on the +15 V side. The ground pin on the -15 V
> > side is only used to ground the sleeve contacts of the jacks. It's
> > not clean vs. dirty or signal vs. power, it's frame ground vs.
> > everything-else-ground.
> 
> Why?  Ground loops?

Yes. You get a star signal & power ground.

Of course, two modules' signal grounds might not be at the same
exact potential which will add an offset to any CV between them. I
think.

-- 
André Majorel http://www.teaser.fr/~amajorel/