[PD] power supply problem on laptop

[Frank Barknecht]

Hallo,
TimBlechmann at gmx.net hat gesagt: // TimBlechmann at gmx.net wrote:

> i've got some problems connecting my laptop (acer aspire) with an amp: 
> if i am using the power supply i am getting noises on the sound cards. both
> on the onboard and on the m-audio quattro. i searched the list archive and
> tried out some hints like putting tape over the ground pins and so on. without
> success.
> 
> i thought about the following possibilities:
> 1. a new (better) power supply
> 
> 2. "cleaning" the power supply with some huge condensers. does who had this
> problem tried this? i don't know if it's to fast to clean the tension peaks.
> 
> 3. since i've got the same problem using the usb sound card, i thought about
> using a usb connection without the power (5V) connection. i don't think that
> the quattro will get the information from the data connection...
> 
> if anyone has tried one of these possibilities or maybe have another idea it
> would be great if you let me know...

Cutting ground on the power supply can really hurt you, so don't do
it. I was bitten by the same problem on my Acer Travelmate. I read
about a lot of things regarding this and I put some links on my
WikiWeb at http://footils.org/cgi-bin/cms/pydiddy/wiki/GroundLoop

I found out, that my ground loop was easy to get rid of, actually.
I had my main non-mobil computer connected to the same amp as the
Laptop/Quattro combo. As soon as I disconnected my main PC, the
humming went away. 

This might work for you in a similar setup, so first try disconnecting
everything else from the amp, like CD players, guitars or what ever. 

Another solution might be going through a so called direct input box
or DI-box. This disconnects ground from the audio-cables, *not* ground
from the laptop's power supply. There also is a ready solution
available with the "Monacor FGA-40" device, BestellNr.06.4370 
You might be able to buy it in a car-audio-shop. 

Then I also mailed Acer if the could send me another power connector
without ground. They told me, that they are not allowed to do that in
Germany by law. 

ciao
-- 
 Frank Barknecht                               _ ______footils.org__