In article ,
Keith G wrote:
I was going to post a suggestion that you simply lift the earth on a
suitable extension lead, but then considered that it would most likely
lead to an hubristic outburst from the bed-wetters here, like Pucci.....

I'd be very pleased if you lifted every 'earth' in your house, Kitty.

--


Dave Plowman London SW
To e-mail, change noise into sound.

Its hard to find consumer items with three core cables, indeed, if my
computer was not connected to the stereo, mine would be floating completely,
and a wonderful source of 50 hz tingles when a metal case is touched. Now of
course one has to be a bit careful about unplugging the sound card leads
while leaning on a meteal cased amplifier!

Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"Jim Lesurf" wrote in message
...
IIUC the tests I've been looking into by Ben Duncan on Russ Andrews mains
cables were done with the earth lead unconnected. This makes me wonder.

Is it legal in the UK to *not* connect the 'earth' wire at the mains
socket
end if it is used with a standard 3-pin socket?

Also, I tend to assume it is normal/good practice to earth one item in the
system, usually the amplifier when 3-wire UK mains is provided. Is this
not
usual these days?

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics
http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On Sat, 27 Jun 2009 07:31:23 GMT, "Brian Gaff"
wrote:

Its hard to find consumer items with three core cables, indeed, if my
computer was not connected to the stereo, mine would be floating completely,
and a wonderful source of 50 hz tingles when a metal case is touched. Now of
course one has to be a bit careful about unplugging the sound card leads
while leaning on a meteal cased amplifier!

I've never yet seen a desktop computer that wasn't fed through an iec
mains socket with all pins connected. Maybe you have a laptop?

"Laurence Payne" wrote in message
...
On Sat, 27 Jun 2009 07:31:23 GMT, "Brian Gaff"
wrote:

Its hard to find consumer items with three core cables, indeed, if my
computer was not connected to the stereo, mine would be floating
completely,
and a wonderful source of 50 hz tingles when a metal case is touched. Now
of
course one has to be a bit careful about unplugging the sound card leads
while leaning on a meteal cased amplifier!

I've never yet seen a desktop computer that wasn't fed through an iec
mains socket with all pins connected. Maybe you have a laptop?

That's also my experience. Even modern laptops have 3-core mains leads.

David.

On Fri, 26 Jun 2009 17:22:56 +0100, Jim Lesurf
wrote:

In article 4a4aec56.1163774312@localhost, Don Pearce
wrote:
On Fri, 26 Jun 2009 16:41:19 +0100, Chris Isbell
wrote:

On Fri, 26 Jun 2009 12:23:17 GMT, (Don Pearce) wrote:

Well, my amplifier certainly ash an earth connection (and so does my
PC, hence the isolating line transformer for the sound card). But all
the auxiliary stuff has mains plugs with a plastic earth pin. They
have kite marks, so I presume they are legal.

Could you possibly provide details of the isolating line transformer,
please? (My work laptop is eathed and causes some 'interesting' noises
when mains powered.)

Thanks,

Yup - I bought it in Maplin. It is a Shark, model VW43W ground loop
isolator.

This makes me wonder as I've not checked. I have assumed USB carries ground
between units, so could produce a loop if both are earthed. Is this
correct?


I imagine so.

d

In article ,
Brian Gaff wrote:
Its hard to find consumer items with three core cables, indeed, if my
computer was not connected to the stereo, mine would be floating
completely, and a wonderful source of 50 hz tingles when a metal case
is touched. Now of course one has to be a bit careful about unplugging
the sound card leads while leaning on a meteal cased amplifier!

That's a bit surprising, Brian, as the standard ATX power supply is
grounded.
Dunno much about laptops - I do have an old one with an external PS - so
that only gets low voltage DC to it.

--
*Windows will never cease *

Dave Plowman London SW
To e-mail, change noise into sound.

On Sat, 27 Jun 2009 07:31:23 GMT, "Brian Gaff"
wrote:

Its hard to find consumer items with three core cables, indeed, if my
computer was not connected to the stereo, mine would be floating completely,
and a wonderful source of 50 hz tingles when a metal case is touched. Now of
course one has to be a bit careful about unplugging the sound card leads
while leaning on a meteal cased amplifier!

Dangers and problems of ungrounded PC
http://www.epanorama.net/documents/p...ounded_pc.html

"Ken" wrote in message
...
On Sat, 27 Jun 2009 07:31:23 GMT, "Brian Gaff"
wrote:


Dangers and problems of ungrounded PC
http://www.epanorama.net/documents/p...ounded_pc.html


Apparently written by someone without a spell-checker who doesn't bother to
proof read his web pages! The grammar is pretty poor too.

David.

"Jim Lesurf" wrote in message
...
In article 4a4aec56.1163774312@localhost, Don Pearce
wrote:
On Fri, 26 Jun 2009 16:41:19 +0100, Chris Isbell
wrote:

On Fri, 26 Jun 2009 12:23:17 GMT, (Don Pearce) wrote:

Well, my amplifier certainly ash an earth connection (and so does my
PC, hence the isolating line transformer for the sound card). But all
the auxiliary stuff has mains plugs with a plastic earth pin. They
have kite marks, so I presume they are legal.

Could you possibly provide details of the isolating line transformer,
please? (My work laptop is eathed and causes some 'interesting' noises
when mains powered.)

Thanks,

Yup - I bought it in Maplin. It is a Shark, model VW43W ground loop
isolator.

This makes me wonder as I've not checked. I have assumed USB carries
ground
between units, so could produce a loop if both are earthed. Is this
correct?


USB does, yes. What units are you interconnecting with USB? I use balanced
SPDIF (like AES/EBU but with consumer metadata) to connect audio from my PC
to the audio system. This overcomes any ground-loop problem.

David.

On Sat, 27 Jun 2009 10:24:16 +0100, "David Looser"
wrote:

"Ken" wrote in message
.. .
On Sat, 27 Jun 2009 07:31:23 GMT, "Brian Gaff"
wrote:


Dangers and problems of ungrounded PC
http://www.epanorama.net/documents/p...ounded_pc.html


Apparently written by someone without a spell-checker who doesn't bother to
proof read his web pages! The grammar is pretty poor too.

David.

I imagine his spell checker is Finnish.

d