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Discussion Starter #1
I guess this only pertains to MY2003

I have heard doing this:

Entertainment said:
The MY03 EHU had a fault in the resistors for the AUX input, this is changed to MY04. So the level is much better in MY04 cars.
Then there is an other fix in cars built from somewhere around w340 and forward, there is 2 resistor (10kohm) added to the PCB that takes care of the background noise that exist when nothing is connected in the AUX input (try this: activate AUX and do not connect anything in the input. You'll hear a background noise). This fix can be done on the AUX cable also. Just add 2 resistors (10kohm) between AUX-R -- GND and AUX-L -- GND. This will drop the noise level by appr. 15dB.
But I would hate to have to solder in resistors...

And I have also heard of GLI's

http://www.radioshack.com/product/index.jsp?productId=2062214&cp=2032059.2032325.2032326&pg=1&y=12&retainProdsInSession=1&x=10&numProdsPerPage=100&parentPage=family

But then I have to purchase a bunch of connectors because i don't have RCA outs on my Sirius, just a 1/8in jack.

And then there is this, but it probably won't get rid of the noise, just cover it up...
http://www.radioshack.com/sm-more-product-information-for-the-boostaroo-3-channel-headphone-audio--pi-2732095.html

Anybody use any of these?

What I don't understand is why would any of those things work? Regardless if something is plugged in or not, you still get noise through the HU, its not the signal that is causing it. Some explanation would be wonderfull, thanks for the help!
 

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i purchased that very same ground insulator from radio shack. it comes with ONE jack converter, but you will need two.. one for the AUX in and one for the connection to your media device.

thankfully i had one at home already.. so it was as simple as connecting the rca cables to both ends. it helped greatly!
 

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Discussion Starter #5
Thanks for the link, i still don't understand how that will eliminate the noise though...

and its not a speed dependent whine, it is more of a constant static noise
 

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robhurlburt said:
I guess this only pertains to MY2003
It extends into some 2004's as well.

GLI probably won't help, as it's an amplfier open source problem. GLI's just contain transformers for DC decoupling.

You can build an intermediate run of cable and solder in the 10K ohm resistors. Or you could remove your current aux cable (in the console) and add them. This is far easier than disassembling the EHU, but not as easy as making a new intermediate cable.
 

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Discussion Starter #7
ctrlz, could you explain a little more?

What do you mean by intermediate cable?

I have no problem removing my cable as I made it and installed it so that should be fairly easy...
 

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robhurlburt said:
ctrlz, could you explain a little more?

What do you mean by intermediate cable?
Just a separate run of cable you would plug into the existing aux port. Your device would plug into the female end of the new cable. This cable could be super short, like 3" or so.

You add the resistors between left and GND and right and GND. if you don't mind opening the console again it's pretty easy to do this at the jack if you already made a cable.
 

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Discussion Starter #9 (Edited)
so you solder the right channel to the ground, and the left channel to the ground, that will eliminate the background noise?

How is that different from a GLI, it seems like I am grounding both channel sides by soldering in the resistors. Isn't the noise in the actual headunit, not from the signal that is being received?

Can I get resistors at radio shack? If not, do you know where i can get them?

What watt resitor do i need? 1/8W, 1/4W, 1/2W?

Does it have to be carbon film or a metal film resistor?

I also have the individual wires plugged into the back of the HU, do you know what the connector P/N is?

Thanks for the help
 

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1/4 or 1/8 W 10K ohm resistors at RadioShack. Cheapest ones. Solder one between each channel and ground.

The noise is small current flow between each channel and ground. This is probably an induced current from alternating electric fields in the local environment (alternator, RF souces, outside world, etc.). The open source wire is acting like an antenna. The small signal is amplified by the EHU. Installing the resistors allows this small current to be dissipated as heat.
 

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Discussion Starter #12
ctrlz said:
1/4 or 1/8 W 10K ohm resistors at RadioShack. Cheapest ones. Solder one between each channel and ground.

The noise is small current flow between each channel and ground. This is probably an induced current from alternating electric fields in the local environment (alternator, RF souces, outside world, etc.). The open source wire is acting like an antenna. The small signal is amplified by the EHU. Installing the resistors allows this small current to be dissipated as heat.
I will try the resistors, but maybe I am not reading into what you are saying correctly.

If I have the noise without the wire hooked up, then it can't be from small current flow between each channel and ground from the wire. Are you saying there is a current flow in the HU? I found no difference between the noise level when the Aux-In cable was hooked up or not, thats why i don't understand how it is acting like an antenna. Maybe its just over my head...

Thanks for the info!
 

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robhurlburt said:
I I found no difference between the noise level when the Aux-In cable was hooked up or not...
Was there a source hooked to the aux cable?
The resistors only solve the noise problem if the noise goes away once you plug in your iPod or whatever. The newer EHU's have these resistors in place.

It's not the presence or absence of the cable that's the issue, it's whether or not a source is connected.
 

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Discussion Starter #14
I am pretty sure there was a source hooked up, my sirius reciever. I tested it with the receiver hooked up, and then unplugged the wire completly and still had background noise

Well for the price, its definatly worth a try
 

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I would try different sources to see if the noise was the same. Try an mp3 player, cd player, etc.

Did you make and install your own cable? And, if so, did you use shielded cable?
If the aux cable is not shielded cable it may need to be replaced with the shielded type. If you bought a Saab or Eatdyne cable rest assured it is the shielded type.
 

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not to step on your feet ctrlz but..

i had the exact same problem. a very annoying background noise that was very loud when my ipod was paused or low volume, but it was still very apparent even when music was playing.

i purchased the ground insulator from radioshack, the EXACT one he posted above.. and it fixed my problem 100%. i now have zero noise/static/intereference when the ipod is connected, disconnected, paused, playing, or anything.

and no this noise wasn't really dependant on the speed of the car.. it seemed pretty uniform (and annoying) at all times.
 

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wtfwill said:
i had the exact same problem. a very annoying background noise that was very loud when my ipod was paused or low volume, but it was still very apparent even when music was playing.
iPods have some unique issues because their line-out is on the low side to conserve battery life. Most people buy some kind of dock/charger with amp to use in-car.

I'm not saying a ground loop isolator won't help here. Just, technically, there can't be a ground loop since the EHU is grounded and any battery-powered device you plug in will also ground through the EHU. The GLI will not eliminate any internal grounding problems within the EHU. Ground loops are direct currents. A GLI uses coupled transformers which only allow alternating currents to pass through. Music signals are AC.
 

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I bought the radioshack GLI he mentions in his first link.

it totally solved the problem in both my 9-3 and my honda.
 

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platypus said:
I bought the radioshack GLI he mentions in his first link.
I would suggest trying it since he's stopping at RS anyway. Most of these RS blister packs can be opened by carefully removing the staple with pliers. If the GLI doesn't work, just repackage it and return it.
 
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