Re: [LAU] RF noise suppression?

On Sat, Apr 03, 2010 at 05:48:43PM -0400, Rick Green wrote:
> I'm using a FOcusrite Saffire pro 26 I/O with ffado, jack, and Ardour to
> make multitrack recordings of live concerts, to my emachines M6810 laptop
> running ubuntustudio. I'm plagued by noise that sounds to me like RF
> interference from the laptop, getting into the audio portions of the
> interface. It's most obvious when I'm at home trying to mix down my
> recordings, as its almost constant in my monitors and most noticable in
> a quiet room, but it also manifests itself sometimes during shows, showing
> up on the input lines to the interface, which are plugged 'half-way' into
> the FOH mixer's channel inserts, so it invades the PA and the performers'
> monitors. WHen that happens, I've no other choice but to abandon the
> recording and shut down the laptop.
>
> Has anyone else encountered this problem? Got any suggestions how to
> filter it? I'm going to try some ferrite cores snapped around the
> firewire cable first. Anything else I might try?
>

I had exactly the same problem, almost exactly 3 years ago when I first gigged with a laptop.

The solution was to lift the ground on the AC adapter, using one of those three-prong-to-two-prong adapters. Haven't had a problem since then, been gigging my ass off the whole time (although a year ago I mostly switched to using my EEE netbook, which only has a two-prong adapter anyway, and never had the problem with it).

-ken
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Received on Sun Apr 4 08:15:01 2010