[linux-audio-user] hum from laptop soundcard

[alex dray]

i think you're out of luck...the point of laptop architecture is to squish 
everything together....with a monitor and usb (which is fairly high voltage) 
so close to an integrated audio card, you cannot avoid magnetic influence as 
shielding at this level is practically impossible....you're best bet (and 
not a very good solution) is to get a breakout box so the actual dac is 
physically outside the laptop. If you come up with better solution please 
let me know,its a problem that frequently drives me nuts




>From: Ben Saylor <bsaylor at Macalester.edu>
>Reply-To: linux-audio-user at music.columbia.edu
>To: linux-audio-user at music.columbia.edu
>Subject: [linux-audio-user] hum from laptop soundcard
>Date: Fri, 18 Apr 2003 13:57:06 +0200
>MIME-Version: 1.0
>Received: from roar.music.columbia.edu ([128.59.195.116]) by 
>mc9-f14.bay6.hotmail.com with Microsoft SMTPSVC(5.0.2195.5600); Fri, 18 Apr 
>2003 11:59:47 -0700
>Received: from roar.music.columbia.edu (IDENT:mailman at localhost 
>[127.0.0.1])by roar.music.columbia.edu (8.11.6/8.11.0) with ESMTP id 
>h3IJ96Q28912;Fri, 18 Apr 2003 15:09:06 -0400
>Received: from mail.Macalester.edu (imap.macalester.edu [141.140.1.16])by 
>roar.music.columbia.edu (8.11.6/8.11.0) with ESMTP id h3IJ8nQ28895for 
><linux-audio-user at music.columbia.edu>; Fri, 18 Apr 2003 15:08:49 -0400
>Received: from CONVERSION-DAEMON.mail.Macalester.edu by mail.Macalester.edu 
>(PMDF V6.2 #30562) id <0HDJ00801Z4HTB at mail.Macalester.edu> for 
>linux-audio-user at music.columbia.edu; Fri, 18 Apr 2003 13:53:05 -0500 (CDT)
>Received: from std16.dorms7.macalester.edu (std16.dorms7.macalester.edu 
>[141.140.107.16]) by mail.Macalester.edu (PMDF V6.2 #30562) with ESMTP id 
><0HDJ007EEZ4HGW at mail.Macalester.edu> for 
>linux-audio-user at music.columbia.edu; Fri, 18 Apr 2003 13:53:05 -0500 (CDT)
>X-Message-Info: UZmYcfFpTCewzfqvyl1d15R59mlxBfYY
>Message-id: <200304181357.06318.bsaylor at macalester.edu>
>User-Agent: KMail/1.5.1
>Sender: linux-audio-user-admin at music.columbia.edu
>Errors-To: linux-audio-user-admin at music.columbia.edu
>X-BeenThere: linux-audio-user at music.columbia.edu
>X-Mailman-Version: 2.0.13
>Precedence: bulk
>List-Help: 
><mailto:linux-audio-user-request at music.columbia.edu?subject=help>
>List-Post: <mailto:linux-audio-user at music.columbia.edu>
>List-Subscribe: 
><http://music.columbia.edu/mailman/listinfo/linux-audio-user>,<mailto:linux-audio-user-request at music.columbia.edu?subject=subscribe>
>List-Id: A list for linux audio users <linux-audio-user.music.columbia.edu>
>List-Unsubscribe: 
><http://music.columbia.edu/mailman/listinfo/linux-audio-user>,<mailto:linux-audio-user-request at music.columbia.edu?subject=unsubscribe>
>List-Archive: <http://music.columbia.edu/pipermail/linux-audio-user/>
>X-Original-Date: Fri, 18 Apr 2003 13:57:06 +0200
>Return-Path: linux-audio-user-admin at music.columbia.edu
>X-OriginalArrivalTime: 18 Apr 2003 18:59:47.0194 (UTC) 
>FILETIME=[AE502DA0:01C305DC]
>
>Hi,
>
>I have a new Dell laptop with a headphone jack as the only external
>audio output.  With headphones, the sound quality is good and there is
>little noise to be heard.  However, if I plug in my monitors, the
>output crackles and hums, regardless of the mixer levels.  There is
>217 hz constant hum, a 125 hz hum when moving windows, and a 689 hz
>whine when I run Pd.  The output crackles when I move the mouse
>(external USB).  I just noticed that it goes away when I unplug the AC
>adaptor.  I think I remember a similar problem coming up on this list
>before, but I had no luck searching the archives.  How can I solve
>this?
>
>Thanks,
>Ben


_________________________________________________________________
MSN 8 with e-mail virus protection service: 2 months FREE*  
http://join.msn.com/?page=features/virus