NoahD

I've been using an iPod in my S4 for quite a while, and just got one of the new 30 gig models. I also got the super-slick Belkin auto adapter that plugs into the lighter socket and provides an audio out jack (which I run through a Blitzsafe adapter to the stereo). The adapter provides a single connector (the new docking connector) to the iPod, which gives both power and line out.

The problem I'm having is that when the iPod is receiving power (through the adapter), even if it's not actually playing a track, I get a whine through the stereo. The whine's pitch is proportional to the engine RPM, so I believe this is what's called alternator whine.

So the question is, how can I get rid of it, and still provide power to the iPod? Is there a filter I can run between the Belkin adapter and the lighter socket? Ultimately, I'd rather hardwire the belkin adapter under the dash (and not have wires running around near the shifter) so having some sort of in-line filter there wouldn't be a problem. But what sort of filter will eliminate this alternator whine?

thanks in advance

ar gecko

I'm very interested in this connection. Have you tried using the audio out jack on the ipod itself instead of the one on the adater? Maybe the whine is coming from the adapter's amp. I'm going to install a 12v socket in the center console and maybe a filter before the socket will clean up the whine. I've heard that the sound level to the blitzsafe adapter without an amp is very low and you have to turn up the volume on the HU to get any volume, does the small amp in the Belkin adapter eliminate this?
Thanks

NoahD

Audio out from the iPod itself, without using the Belkin adapter at all, is fine. yes, the volume is low, but if I have the ipod all the way up, and the stereo at a reasonable level (slightly higher than for radio/CD) it's fine.

I have not tried using the audio out from the iPod when just getting power from the belkin adapter. However, I got the same whine with my old iPod with a different lighter socket -> power adapter, using the old ipod's audio out. So it's definitely something resulting from the power socket.

the amp in the belkin adapter lets you reduce the ipod volume a bit; I don't think the amp is what's causing this whine. The real question is, do I want a ground loop isolator, or a power filter? I think I want a power filter, because it's RPM-dependent noise which is NOT what you get with a ground loop. Right?

Igor2003

I would suggest to try to connect audio minus (outer terminals of your RCA) to headunit minus, e.g. grounding audio. This helped me to eliminate same noise when adding amp to nonBose A4 audio system. Let me know if this worked.

JustJeff

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