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Help Car charger, audio cable, and noise interference

malklavious

Member
Nov 9, 2009
54
2
On my first road trip with my new Droid I eagerly hooked up an 1/8" stereo cable between my Droid and car stereo with great results. Then I plugged in my car charger (brand new "RocketFish" from Best Buy) and there is a ton of audio interference. As I rev the engine of my car there is a high-pitched whine that is almost the same pitch as the RPM's of the engine.

Has anyone else with a RocketFish car charger have the same problem?

Has anyone else had this problem with an official Verizon car charger?

Has anyone else had this problem at all?

Thanks!
 
I'm having the same issue with my Droid and car audio system. I have a generic Motorola car charger from K-Mart, it was only $10. Other audio inputs such as my iPod work flawlessly, my Droid works flawlessly until I plug in the car charger. I'm experiencing the same engine revving frequency interference as you described. Also I hear interference when scrolling on my Droid through Apps. It's really strange.

I'm thinking it may be a Droid issue because the Droid is allowing the interference from the car changer to be transmitted through to the Aux out. But I'm not sure.

Any other information on this issue would be greatly appreciated. I'll update if I find anything.
 
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Sorry to bump an old post, but you never did get your answer.

This issue would be what's called a ground loop problem. It would happen with a droid, iphone, ipod, etc... doesn't matter (i've been dealing with it for years, but it's just a tiny bit louder on the droid then my old apple gear).

I'm planning on fixing it tomorrow by opening up my dash and finding a better ground for the cigarette lighter. BUT, you can also fix it by purchasing a ground loop isolator (google/amazon search it).

Another charger however, won't fix the issue at all.
 
Upvote 0
Sorry to bump an old post, but you never did get your answer.

This issue would be what's called a ground loop problem. It would happen with a droid, iphone, ipod, etc... doesn't matter (i've been dealing with it for years, but it's just a tiny bit louder on the droid then my old apple gear).

I'm planning on fixing it tomorrow by opening up my dash and finding a better ground for the cigarette lighter. BUT, you can also fix it by purchasing a ground loop isolator (google/amazon search it).

Another charger however, won't fix the issue at all.
Or just a [FONT=Times New Roman, Times, serif]alternator noise. Speacially if it a rebuilt unit or an old unit starting to go bad.[/FONT]
 
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I tried a new charger and phone today. I tried a Motorola charger instead of a Rocketfish and same thing. I also tired a new Droid and same thing. However, I tried my friends car with the Motorola charger and it worked fine. Now it looks like it is either my stereo ground, or the aux cable. I will let you know when I can try these.(Maybe a week) sho95 did you get a chance to ground yours yet?
 
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You've got a ground loop. What you need is an audio cable that is transformer coupled. I'm not sure where you can buy one but try searching for a ground isolated audio cable or transformer isolated audio cable.... Something like that... Worst case you can just find and buy an audio transformer and make your own (thats what I'd do...) but explaining it here is probably beyond the scope of what you're looking for.
 
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You've got a ground loop. What you need is an audio cable that is transformer coupled. I'm not sure where you can buy one but try searching for a ground isolated audio cable or transformer isolated audio cable.... Something like that... Worst case you can just find and buy an audio transformer and make your own (thats what I'd do...) but explaining it here is probably beyond the scope of what you're looking for.


it's called cycle 60 hum. the same as fluorescent lights. anyway, if you've ever bought a pc monitor, it probably came with the exact audio cable you're talking about. you can find them at just about any best buy, office depot ... blah blah, you get it. it will help out, but you can never truly get it all out if you charge while using a cable to plug into your audio system. if you use bluetooth, the problem won't be there.
 
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Definitely a ground loop. If you rev your engine with the phone plugged in you should hear the pitch of the whine go up with the rpm's. It would be no different if you plugged an ipod or your laptop into your stereo while they were charging in the car. The easiest/cheapest way to kill the noise is to unplug the charger while the phone is plugged into your stereo, but the adaptor from crutchfield should do the trick.
I don't know why car companies haven't caught up on this yet. My wife and I have two different 2007 Toyota vehicles with standard aux inputs and both share this annoying problem.
 
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