David Looser wrote:
"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.


Mine hasn't for some reason (Samsung NC10).

Rob

In article ,
David Looser wrote:
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.

Plain ol' balanced here. Don't think SPDIF existed when I did it. I later
changed the sound card to one with SPDIF and use and external convertor -
the actual audio side of the card isn't that good.

--
*The more I learn about women, the more I love my car

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

In article , David Looser
wrote:
"Jim Lesurf" wrote in message
...


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?

At the moment Shuttle XPC to Cambridge Audio DACmagic, then from that via
optical fibre to a Meridian 563 DAC. So at present I am just using the
DACmagic as a USB to spdif optical convertor. But I suspect in future I'll
be wanting to use a USB DAC to provide analogue outputs. e.g. I eventually
want to use a small notebook as a 'net radio and iPlayer' for the living
room AV system.

In fact, I'd be interested to know if anyone here has used any machines
like the Dell mini 9 with a USB DAC and Linux. More generally, I'd be
interested in knowing of small machines that are, mechanically, totally
silent (incuding the PSU if a laptop, etc).

The Shuttle I'm using is silent. But my old laptop sounds like a
helicopter.

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.

Indeed. However units like the DACmagic should allow the user to obtain
analogue from USB. FWIW I had no signs of earth loop or other problems when
I used the DACmagic that way with my computers. But I presume this is a
risk when using other USB dacs or systems.

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 12:16:52 +0100, Jim Lesurf
wrote:

In fact, I'd be interested to know if anyone here has used any machines
like the Dell mini 9 with a USB DAC and Linux. More generally, I'd be
interested in knowing of small machines that are, mechanically, totally
silent (incuding the PSU if a laptop, etc).

I use an ASUS EEE PC 701 running Ubuntu with an Edirol UA-25. It
sounds quite good through my electrostatic speakers ;-)

The EEE 701 is unfortunately not totally silent. If has a fan that
cuts in when the computer gets warm.

It does have the advantage of not being grounded when mains powered,
so does not provide a ground loop path.

--
Chris Isbell
Southampton, UK

On Fri, 26 Jun 2009 15:43:24 GMT, (Don Pearce) wrote:

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

Thanks, I will give it a whirl.

(I used to run balanced into a Behringer mixer, but no longer have the
space to accommodate this.)

--
Chris Isbell
Southampton, UK

On Sat, 27 Jun 2009 19:57:58 +0100, Chris Isbell
wrote:

I use an ASUS EEE PC 701 running Ubuntu with an Edirol UA-25. It
sounds quite good through my electrostatic speakers ;-)

The EEE 701 is unfortunately not totally silent. If has a fan that
cuts in when the computer gets warm.

It does have the advantage of not being grounded when mains powered,
so does not provide a ground loop path.

Unfortunately, the lack of a ground connection to a laptop power
supply is no guarantee of acceptable audio quality when connected to
an external amp and speaker. Some can be rescued by disabling part of
the power management software. Some will only work well with the
battery physically removed. Some when running on battery with the psu
removed.

But as you're lucky enough to have a setup that works well, you need
worry about none of this! :-)

On Sat, 27 Jun 2009 20:16:14 +0100, Laurence Payne
wrote:

Unfortunately, the lack of a ground connection to a laptop power
supply is no guarantee of acceptable audio quality when connected to
an external amp and speaker. Some can be rescued by disabling part of
the power management software. Some will only work well with the
battery physically removed. Some when running on battery with the psu
removed.

But as you're lucky enough to have a setup that works well, you need
worry about none of this! :-)

I must just be lucky then!

About the only problem I find is that the screen saver kicks in on
streaming videos. (This is probably not a problem for most pop videos
- but classical operas usually last for more than three minutes. :^)

Slightly off topic, the Franco-German channel Arte is starting to put
complete classical concerts and operas on line at
http://liveweb.arte.tv/. This has not been going long, but is starting
to look promising.

--
Chris Isbell
Southampton, UK

In article , Chris Isbell
wrote:
On Sat, 27 Jun 2009 12:16:52 +0100, Jim Lesurf
wrote:

In fact, I'd be interested to know if anyone here has used any machines
like the Dell mini 9 with a USB DAC and Linux. More generally, I'd be
interested in knowing of small machines that are, mechanically,
totally silent (incuding the PSU if a laptop, etc).

I use an ASUS EEE PC 701 running Ubuntu with an Edirol UA-25. It sounds
quite good through my electrostatic speakers ;-)

The EEE 701 is unfortunately not totally silent. If has a fan that cuts
in when the computer gets warm.

That rules it (and most other computers) it out for me as a means of
playing audio. Even tiny noises from fans, etc, I eventually find annoying.

Alas, this is another area where magazine 'reviews' generally fail to give
useful info. Linux Format recently commented that the Dell is 'silent',
hence my mentioning it. However even there they didn't say if their comment
included the psu.

One of the things I do find baffling about consumer equipment is the way
people seem to accept items are noisy without comment. Particularly weird
when they are used to play music, etc. I still recall briefly trying a Sony
DVD Videorecorder. The fans in this were so loud I could hear them from
another room! Hopeless for even dialogue, let along any music below mf!
When I asked in the shop I got an baffled, "The all do it, Sir" type
response. Patently untrue, of course, as I found other machines that were
considerably quieter.

FWIW having been reading computer mags again in recent months I've noticed
just how little the 'reviews' actually tell you.

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 Sun, 28 Jun 2009 09:22:02 +0100, Chris Isbell
wrote:

About the only problem I find is that the screen saver kicks in on
streaming videos. (This is probably not a problem for most pop videos
- but classical operas usually last for more than three minutes. :^)

Well, you can change that easily enough.

On Sun, 28 Jun 2009 09:25:55 +0100, Jim Lesurf
wrote:

FWIW having been reading computer mags again in recent months I've noticed
just how little the 'reviews' actually tell you.

Ever delved into a "Which" report on a topic you knew something about?
They have a genius for missing the point.