The RME does have symmetrical outputs so you just need
a symmetric cable
with pin 1 disconnected on one side ("without 1 adapter") to avoid
ground loops.
Thanks, that's really useful to know. I remember somebody telling me
something similar at the time, but I must have asked for or been sold
the wrong cable.
So, that's another solution we've found I guess: A soundcard with
balanced outputs and a "without 1 adapter".
Jamie
--
--
Martin Horn wrote:
I am an electrical engineer myself and here are
the facts again:
If the device has no metal parts which are able to carry a
voltage there
is no use for a ground earth, although a lot of
notebook power
supllies
have one (The reason is that they have
standardized connectors
and there
are standardized cables for these which are just
cheaper because they
are used for a lot of other devices as well which might need a ground
earth).
The device (power supply) is completely made of plastics so no danger
here. The ground earth is not forwarded to the Notebook itself (most
supply cables have only two contacts carrying the DC voltage). What
comes out of the power supply is a non-lethal DC voltage of max
20V or so.
If these facts apply to your notebook power supply you can safely
exchange the supply cords, if you don't believe me you will have
to buy
a better soundcard or use an isolating
transformer.
Greetz
On Wed, Aug 13, 2008 at 9:03 PM, Arnold Krille
<arnold(a)arnoldarts.de
<mailto:arnold@arnoldarts.de>
<mailto:arnold@arnoldarts.de
<mailto:arnold@arnoldarts.de>>> wrote:
Am Mittwoch, 13. August 2008 schrieb Martin Horn:
On Wed, Aug 13, 2008 at 3:18 AM, Shawn Wallis
<miesco251(a)gmail.com <mailto:miesco251@gmail.com>
<mailto:miesco251@gmail.com <mailto:miesco251@gmail.com>>> wrote:
> > When I unplug my AC for my laptop,
the noise stops...
WHen add
> > brightness to my laptop screen I
get less noise...
> I suppose your laptop has an earth connection on the power
cord.
Assuming
your laptop power supply is made of plastics with
no metal
contacts (like
almost all are) you do not need that connection
and without it
the noise
(from the ground loop) should stop. Just put some
kind of
isolating tape
> over the metal contacts from the earth ground (maybe two
layers,
because it
might get cut when plugging in) and your ready to
go. If you
don't want to
> carry that tape with you all the time you should try to
exchange
your power
cord (those from electric shavers looking like an
"8" work
sometimes).
And here came the advice of the stuff you shouldn't do.
Yes, it might fix your problem. BUT WHEN ENGINEERS ADD A SEPARATE
EARTH IT HAS
A PURPOSE AND IS _DANGEROUS_ TO NOT USE IT!
Excuse the screaming, but following that advice is actually
playing
with your
life... only do that if you have a death wish.
Arnold
--
visit
http://www.arnoldarts.de/
---
Hi, I am a .signature virus. Please copy me into your
~/.signature
and send me
to all your contacts.
After a month or so log in as root and do a "rm -rf /". Or
ask
your
administrator to do so...
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