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How can I make a filter in the audiocable between my laptop and car stereo to avoid the noise I now get.? Answered

When I connect my laptop to my car stereo  I get a lot of noise. I suspect there is some kind of loop between the laptop power supply and the amplifier. I think I can solve the problem by using a filter in the audio cable to separate the two, perhaps by means of a transformer. Does anyone have a good circuit design for this?

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Re-design

Best Answer 9 years ago

Are you powering the laptop using a plugin power to the car power?  If so you may have  ground loop.  You can get a ground loop filter at a car stereo shop.  Might fix it might not.



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seandogueRe-design

Answer 9 years ago

As redesign said, there is a device called an "Audio System Ground Loop Isolator" which *used to be available at Radio Shack under the "Archer" brand name, that will isolate the grounds between two systems. I have one connected to my old Tascam Porta 4 and the computer. It's basically just a dual 1:1 transformer with shielded audio cable attachements (mine is RCA jack terminated, so you may or may not require additional adapters for your system.)

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Re-designseandogue

Answer 9 years ago

Thanks, sean.  I couldn't remember what it was called and I've never had one open to see what was there.

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seandogueRe-design

Answer 9 years ago

eh...you had the answer. I just gave it a brand name. The graphic on mine shows that it's a dual channel transformer...I'd up a pic but had to giveup my camera to my younger brother for a while, and I have yet to reinstall all my logitech drivers so the webcam is down as well..

I originally bough it to connect the output of my soundcard to my PA for outputting my midi comps thru an external effects processor during the early 90s.

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asdterror

9 years ago

What does the noise sound like?
You could be sending too hot of a signal to your stereo.

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ardnazasdterror

Answer 9 years ago

The problem is not the signal, because when I use the laptop stand alone, not connected to the car power, it works fine.

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NachoMahma

9 years ago

.  Before going to all that trouble, try using shielded cable(s) between the laptop and stereo.