[linux-audio-user] hum from laptop soundcard

[derek holzer]

yes,
 
same here. it is very common for laptops to have terrible ground loop 
problems when connected to other equipment, which is what you are 
hearing. the two solutions i can think of:

a ) use a DI box between your laptop audio output and everything else to 
lift the signal off ground--an expensive option if you are just using 
the headphone out, of course!

or  

b ) find another way to remove your laptop from ground. using batteries 
is one, but then your processor slips into a lower mode and you lose 
some of that computing power you paid for. a friend suggested using a 
powerstrip that either has no ground or has had its ground removed. 
haven't tried it yet, but that sounds like the best bet. better than 
hacking the grounds off your AC adaptor, at least... :-)

best,
derek


juto aviten wrote:

> Dear friends ,
> i have also problem with hum when i used sound with my laptop, it's 
> the plug, when i used only battery, it's perfect... but when i put 
> directly electricity... it's finish, i have a big hum and it's 
> terrible when you make sound or playing live... but i think it's an 
> hardware problem not software. But is someone find a solution (without 
> the fact to buy an external card) as for example find another AC 
> adaptater...??? Mylaptop is Gericom and i use Mandrake 9.0... if 
> you've got an idea, your just welcoming... and thanks you.
>
>
> best
>
>
> juto
>