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@xxxxxxxxxxxxxx> >Reply-To: linux-audio-user@xxxxxxxxxxxxxxxxxx >To: linux-audio-user@xxxxxxxxxxxxxxxxxx >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@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@xxxxxxxxxxxxxxxxxx>; 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@xxxxxxxxxxxxxxxxxxx> for >linux-audio-user@xxxxxxxxxxxxxxxxxx; 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@xxxxxxxxxxxxxxxxxxx> for >linux-audio-user@xxxxxxxxxxxxxxxxxx; Fri, 18 Apr 2003 13:53:05 -0500 (CDT) >X-Message-Info: UZmYcfFpTCewzfqvyl1d15R59mlxBfYY >Message-id: <200304181357.06318.bsaylor@xxxxxxxxxxxxxx> >User-Agent: KMail/1.5.1 >Sender: linux-audio-user-admin@xxxxxxxxxxxxxxxxxx >Errors-To: linux-audio-user-admin@xxxxxxxxxxxxxxxxxx >X-BeenThere: linux-audio-user@xxxxxxxxxxxxxxxxxx >X-Mailman-Version: 2.0.13 >Precedence: bulk >List-Help: ><mailto:linux-audio-user-request@xxxxxxxxxxxxxxxxxx?subject=help> >List-Post: <mailto:linux-audio-user@xxxxxxxxxxxxxxxxxx> >List-Subscribe: ><http://music.columbia.edu/mailman/listinfo/linux-audio-user>,<mailto:linux-audio-user-request@xxxxxxxxxxxxxxxxxx?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@xxxxxxxxxxxxxxxxxx?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@xxxxxxxxxxxxxxxxxx >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
