Annoying "hiss" from line out in laptop when using AC, Disappears when running from battery |
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Annoying "hiss" from line out in laptop when using AC, Disappears when running from battery |
  May 21 2007, 08:00
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#1
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 Group: Members Posts: 1190 Joined: 12-January 06 From: Cambridge, MA Member No.: 27052  |
Hi
I've got a dell e1505 with the onboard sound; I use my Shure E2Cs for listening. I've noticed an annoying hissing sound... here are the details * The hissing sound is present when using earphones; it is not noticeable when using laptop speakers. * The sound is present ONLY when using the AC adapter... when running on battery, there is NO hissing sound * The sound is not "constant". When there is hard drive use, the hissing noise is supplemented by a different noise. This extra "noise" becomes louder as the hard drive activity increases. Again, the extra sound is non-existent when running from battery. This hissing sound is a severe annoyance because my laptop is my ONLY means to listen to music. I've considered the following "solutions", but don't know if they are effective. Could someone please guide me: * Using a ground lift (i read in some other thread that someone had a good result, but i don't think his condition was similar to mine) * Getting a new PCMCIA sound card- I was considering getting the Audigy 2 ZS. Will it help? Given that the noise seems to be somehow related to power, am i right in believing that the audigy 2 zs will also suffer similar fate? * Getting a USB sound card. Someone in another thread got a Behringer USB sound card and apparently it helped a lot. Again, it doesn't have an external power supply so I'm doubtful as to whether the problem will go away. Can anyone suggest solutions / correct my above assumptions? This post has been edited by kanak: May 21 2007, 08:02 |
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May 21 2007, 08:11
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#2
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Group: Members Posts: 2036 Joined: 31-August 05 Member No.: 24222 |
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May 21 2007, 08:20
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#3
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 Group: Members (Donating) Posts: 678 Joined: 10-December 01 From: Belgium Member No.: 622 |
I've had this problem too. Getting a new sound card will probably not help, since I experienced it with both an Echo Indigo IO and a Firewire Audiophile.
I solved it using a ground loop isolator: http://www.radioshack.com/sm-see-all-needs...pi-2062214.html This post has been edited by PoisonDan: May 21 2007, 08:23 -------------------- Over thinking, over analyzing separates the body from the mind.
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May 21 2007, 18:07
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#4
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Group: Members Posts: 2036 Joined: 31-August 05 Member No.: 24222 |
That is one approach that sometimes works but you should probably look at the different approaches discussed in the thread I referenced.
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May 21 2007, 18:32
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#5
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Group: Members Posts: 1190 Joined: 12-January 06 From: Cambridge, MA Member No.: 27052 |
QUOTE (AndyH-ha @ May 21 2007, 03:11)  Thank you for this very informative resource. QUOTE (PoisonDan @ May 21 2007, 03:20) I solved it using a ground loop isolator: http://www.radioshack.com/sm-see-all-needs...pi-2062214.html I'm confused about the isolater. I can't figure out where the jacks would go. Could you give more details? |
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May 21 2007, 18:53
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#6
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Group: Members Posts: 8 Joined: 14-April 06 Member No.: 29503 |
Try a 3 prong to 2 prong ground adapter. This is the cheapest way to get rid of a ground loop. You probably have one of these around the house anyway.
link |
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May 21 2007, 18:55
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#7
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Group: Members Posts: 1190 Joined: 12-January 06 From: Cambridge, MA Member No.: 27052 |
QUOTE (craigbald @ May 21 2007, 13:53) Try a 3 prong to 2 prong ground adapter. This is the cheapest way to get rid of a ground loop. You probably have one of these around the house anyway. link Although my adapter has only 2 pins, I tried it just for the heck of it... no change. |
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May 21 2007, 19:54
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#8
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Group: Members Posts: 3080 Joined: 1-September 05 From: SE Pennsylvania Member No.: 24233 |
The power supply module for your laptop already provides ground loop isolation. Besides, ground loops only occur when you connect two devices that are both grounded through their power cords, and in your case you had zero.
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May 21 2007, 20:06
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#9
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Group: Members Posts: 1190 Joined: 12-January 06 From: Cambridge, MA Member No.: 27052 |
Something weird just happened.
I booted into safe mode without networking, and all of a sudden it was dead quiet (like running from a battery). I think the problem is with the driver (sigmatel driver) and i'm trying to fix it. I'll post updates. |
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May 21 2007, 23:14
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#10
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Group: Members Posts: 2036 Joined: 31-August 05 Member No.: 24222 |
Ethernet cards do cause problems with audio in some setups. A separate hardware profile for audio, wherein the ethernet is disabled, may be a solution.
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May 22 2007, 00:41
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#11
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 Group: Members Posts: 132 Joined: 26-January 02 Member No.: 1171 |
I had the same problem and solved it with a DIY shielded cable, I'm sure a properly shielded aftermarket cable (coaxial) will give the same effect.
pic 1 pic 2 -------------------- Blubb
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Lo-Fi Version | Time is now: 21st May 2013 - 14:50 |
