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

Will Godfrey willgodfrey at musically.me.uk
Fri May 9 18:14:53 UTC 2014


On Fri, 09 May 2014 13:01:57 -0500
Reuben Martin <reuben.m at gmail.com> wrote:

> On Friday, May 09, 2014 06:05:47 AM Ralf Mardorf wrote:
> > 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".
> > 
> 
> I'm not suggesting to cut the ground pin off. When you use an AC ground lift 
> they come with a metal ring to re-direct the ground connection so that 
> equipment using different power sources can share a common ground.
> 

Link to highly dangerous item not repeated!

How on earth is this legal? Do you *really* think most people will be savvy
enough to know that you're supposed to connect the tab to a proper earth?
Would they even know what a proper earth was?

There is absolutely no way of ensuring the earth is ever connected at all! A
properly designed 3pin connector ensures the earth is always connected first,
and disconnected last. It's the *only* safe way to work.

-- 
Will J Godfrey
http://www.musically.me.uk
Say you have a poem and I have a tune.
Exchange them and we can both have a poem, a tune, and a song.


More information about the Linux-audio-user mailing list