Engine Sound with Belkin charger

[SolakiewiczAm]

I'm sorry if this question has been answered already, but I have searched the forum, to no avail.

Ok, I have a 3g 40GB connected through a sony auxilliary input adapter using the line out function on the belkin auto charger. The Belkin auto charger is plugged into an additional acessory outlet, which I have powered directly from the car battery. The only problem is, when I have the Ipod connected through the belkin car charger, every time the engine goes faster, I can hear a hiss that increase with the speed of the engine. I tried installing a noise filter, but it barely reduced the noise. Has anyone else had the same problem? does anyone have any tips?

[elsanto]

Try getting power from another source.. ie if you tapped the extra lighter off the exisiting lighter, try tapping it off of the head units power instead. also make sure its grounded to the same ground as the head unit. its cause by a ground loop.

['_']

go to radioshack and get a ground-loop isolator for $15

[SolakiewiczAm]

I have the accessory outlet powered directly from the battery, with a noise filter on the same line, which might I add was a waste of money because it barely make a difference. I'm thinking it might be the alternator.

[dbett]

Originally posted by SolakiewiczAm
I have the accessory outlet powered directly from the battery, with a noise filter on the same line, which might I add was a waste of money because it barely make a difference. I'm thinking it might be the alternator.

A noise filter is not the same as a ground loop isolator. The ground loop isolator goes on the RCA lines - not the power lines.

Here's the Radio Shack page showing the ground loop isolator they sell. (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=270-054)

Also, you may be getting a ground loop precisely because you are powering the iPod directly from the battery. Although you can run a "hot" wire from the battery, ideally, you want the ground wire to be grounded at the same location as the headunit (radio) is grounded.

Otherwise, there may be a different resistance to ground between the headunit and the iPod. And that's what causes a ground loop.

Good luck.

[SASniper]

Good technical artical on this thing:

http://www.audiocontrol.com/techpapers/tech1002.pdf