[LAU] Ground lifts, TRS, etc. to PA? USB/other signal crossover to audio?

[Ralf Mardorf]

On Thu, 2014-05-08 at 18:02 -0500, Reuben Martin wrote:
> On Friday, May 09, 2014 12:44:00 AM Jörn Nettingsmeier wrote:
> > On 05/08/2014 09:30 PM, Jonathan E Brickman wrote:
> > >  AC power ground lifts sometimes have helped, sometimes
> > 
> > There is no such thing as an AC power ground lift. The correct term, and
> > please don't take it personally, is _criminal_ _incompetence_.
> > 
> 
> It sometimes makes sense to lift the AC ground if you are pulling power from 
> more than one source. (To prevent ground loops) As long everything is grounded 
> to the remaining source correctly.

Potential difference by getting the power from different main jacks or
experiencing ground loops, because you don't care about a correct
grounding are no excuse to give a life-endangering "hint".