[LAU] OT interference / grounding problems

pete shorthose zenadsl6252 at zen.co.uk
Fri Feb 20 04:52:58 EST 2009

On Wed, 18 Feb 2009 04:04:57 +0000
pete shorthose <zenadsl6252 at zen.co.uk> wrote:

> On Tue, 17 Feb 2009 21:02:02 -0500
> carmen <_ at whats-your.name> wrote:
> > > It may just be that it took the introduction of better quality gear for me to hear the effects above the usual
> > > din but then these static like snapping noises are very distinct. 
> > 
> > the suggested ground topology is a star or radial shape,
> > 
> > path to ground from each device is never thru another device, and potentials are as similar as possible
> I have an approximate radial setup but the mixer would be the hub. Thing is and as I said, I've tried to
> use some of these things in isolation. (only the zoom H4 or only the mixer, both have integral monitoring so
> no need for an amp or pc) but I still see it. (well, hear it)
> > do you have a metal radiator pipe? or barring that a 3 prong wiring?
> Ah, moved the radiator recently. I could run a cable tho. 
> > are you using 2-pronged gear or 3? it may be that your house ground is not properly grounded (bad)
> well AFAIK, the house is grounded and being in the UK the sockets are all 3 pronged. that said, I'm pretty sure
> that non of them use the 3rd prong. (plastic tab instead of a metal prong or 2 core flat cables)
> > or strong induced currents from close 60hz mains cabling (perhaps even 120v is enough at a close distance)
> > 
> > i use alligator-clipp terminated cables, to grip onto the metal box around a USB port,
> > 
> > then hook that to the negative battery terminal of my amp. then tap this wire and connect to the radiator pipe
> > 
> >  (shuts shit up pretty good).........
> Cool, ty. I'll try a few things. I'll also say goodbye now in case I'm found dead tomorrow with a spectacular new
> hairstyle. 

Problem solved I think. I tried using someone's Dell XPS laptop (almost identical to my 9400) and the problems
disappeared. Indeed, noise levels dropped vs using the devices in isolation. The difference? The 9400 has
a 3 core earthed AC adaptor and non of my other gear is earthed at all. After googling around I also discovered
that this is why I've been getting electric shocks from the metal parts on my 9400 so hopefully I can get an earthed
AC adapter for this laptop.

pete .

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