Aux ground loop

[88mustanggt]

I have the annoying ground loop noise when I plug my device into the cig lighter and aux port.

the tsb T-SB-0067-08 addresses this issue but I don't want to spend almost 200 bucks for the parts.

typically this is a grounding issue, is there a easier way of fixing this like grounding the cig lighter somewhere or I dono something else?

 

[Sapere]

I got a 3.5mm ground loop isolator off Amazon for like $15 bucks a couple years ago, and that did the trick. I've since replaced the whole head-unit so I can't remember exactly, but I think this was the one.

 

[kevinpt]

I have the annoying ground loop noise when I plug my device into the cig lighter and aux port.

the tsb T-SB-0067-08 addresses this issue but I don't want to spend almost 200 bucks for the parts.

typically this is a grounding issue, is there a easier way of fixing this like grounding the cig lighter somewhere or I dono something else?

i just ended up using the inverter in the console and have not used a 12volt outlet in a while. only use it when charging my gopro

 

[zopperman]

I got a 3.5mm ground loop isolator off Amazon for like $15 bucks a couple years ago, and that did the trick. I've since replaced the whole head-unit so I can't remember exactly, but I think this was the one.

How's this doohickey work?

 

[Sapere]

How's this doohickey work?

When he plugs in his DC phone charger to the cig lighter, the headunit amplifies the difference between the signal on the conductor of the Aux cable and the stereo's ground. In this case, Toyota has used poorly designed input circuitry which allows the cig lighter power ground to have too much of an influence on the signal (not enough isolation). This causes a small amount of fluctuating DC current to flow through the audio shield which allows noise (from the voltage drop across the chassis) to enter the signal path. The 2 ground paths create a ground loop.

The ground loop isolator doohickey uses a filter (isolation transformer) for each channel. In the isolation transformer, the audio is magnetically coupled through the transformer's core. Since DC cannot flow the transformer, the DC path is cut and the noise is eliminated.

 

[88mustanggt]

when he plugs in his dc phone charger to the cig lighter, the headunit amplifies the difference between the signal on the conductor of the aux cable and the stereo's ground. In this case, toyota has used poorly designed input circuitry which allows the cig lighter power ground to have too much of an influence on the signal (not enough isolation). This causes a small amount of fluctuating dc current to flow through the audio shield which allows noise (from the voltage drop across the chassis) to enter the signal path. The 2 ground paths create a ground loop.

The ground loop isolator doohickey uses a filter (isolation transformer) for each channel. In the isolation transformer, the audio is magnetically coupled through the transformer's core. Since dc cannot flow the transformer, the dc path is cut and the noise is eliminated.

would re-grounding the cig lighter fix it?

 

[ddnww]

I always start with the cheapest route

I would try grounding it first. as short as possible.

 

[zopperman]

When he plugs in his DC phone charger to the cig lighter, the headunit amplifies the difference between the signal on the conductor of the Aux cable and the stereo's ground. In this case, Toyota has used poorly designed input circuitry which allows the cig lighter power ground to have too much of an influence on the signal (not enough isolation). This causes a small amount of fluctuating DC current to flow through the audio shield which allows noise (from the voltage drop across the chassis) to enter the signal path. The 2 ground paths create a ground loop.

The ground loop isolator doohickey uses a filter (isolation transformer) for each channel. In the isolation transformer, the audio is magnetically coupled through the transformer's core. Since DC cannot flow the transformer, the DC path is cut and the noise is eliminated.

where does it plug in and stuff?

 

[ddnww]

where does it plug in and stuff?

traditionally , it would go inline between the headunit and amplifier using the rca's. in this case, i don't know.:noidea:

 

[Sapere]

would re-grounding the cig lighter fix it?

The cig lighter is already grounded to the chassis (hence the loop). However I couldn't say one way or another if regrounding it or using a different gauge wire would be enough to eliminate the DC flow.

where does it plug in and stuff?

It's an in-line filter. It goes between the 3.5mm audio cable that plugs into the headphone jack of his device and the Aux assembly plug in the console.

 

[riceandpho]

is there noise when its not plug in the charger? i know my motorola atrix do this, have some noise when i charge my phone and playing through aux to my headunit. but when its not plugged in the charger, there is no noise.

 

[Sapere]

is there noise when its not plug in the charger? i know my motorola atrix do this, have some noise when i charge my phone and playing through aux to my headunit. but when its not plugged in the charger, there is no noise.

That's the issue he's trying to resolve, being able to simultaneously charge/play his device without the accompanying noise. The charging creates the ground loop, the $15 ground loop isolator eliminates the noise.

It's either that or the TSB, which is essentially the exact same thing. They install an in-line filter into the AUX port wire harness for like $200.

 

[zopperman]

The cig lighter is already grounded to the chassis (hence the loop). However I couldn't say one way or another if regrounding it or using a different gauge wire would be enough to eliminate the DC flow.



It's an in-line filter. It goes between the 3.5mm audio cable that plugs into the headphone jack of his device and the Aux assembly plug in the console.

what if you use bluetooth?

 

[Sapere]

what if you use bluetooth?

Because there are no wires for current interference on the audio signal, there would be no noise through bluetooth.

The factory radio on my SR5 was not bluetooth compatible, so I did not have that option. While I ultimately replaced the headunit, the isolator was a cheap fix for this issue in the interim.

 

[ddnww]

The cig lighter is already grounded to the chassis (hence the loop). However I couldn't say one way or another if regrounding it or using a different gauge wire would be enough to eliminate the DC flow.

head units are already grounded when people get electrical interference as well, but adding a better ground usually eliminates this. Like you said, I couldn't say one way or another if regrounding it or using a different gauge wire would be enough to eliminate the DC flow, but its a good start. i wouldn't want to have to have an isolator between my device and jack. besides, isolators are more of a bandaid than an remedy.

 

[88mustanggt]

head units are already grounded when people get electrical interference as well, but adding a better ground usually eliminates this. Like you said, I couldn't say one way or another if regrounding it or using a different gauge wire would be enough to eliminate the DC flow, but its a good start. i wouldn't want to have to have an isolator between my device and jack. besides, isolators are more of a bandaid than an remedy.

exactly why I don't want an isolater. not that I have a problem spending 15 bucks on one. reviews on amazon say some people it doesn't get rid of it all, some say it makes the music flat. I guess ill have to open it all up find the grounds and re-ground or clean them up. was hoping someone else had tried to fix this without buying the band aid. in the end I do wana get a navy head unit but not now.

 

[Sapere]

head units are already grounded when people get electrical interference as well, but adding a better ground usually eliminates this. Like you said, I couldn't say one way or another if regrounding it or using a different gauge wire would be enough to eliminate the DC flow, but its a good start. i wouldn't want to have to have an isolator between my device and jack. besides, isolators are more of a bandaid than an remedy.

I agree, it is absolutely a grounding issue, and it's worth a shot if you're not keen on the isolator. However I don't see why you wouldn't be. The isolation transformers have a 1:1 ratio which neither boosts nor cuts the audio level. Plus you don't have to tear apart your console to re-route the ground. In any case, I was offering a cheaper bandaid than the equivalent bandaid offered by Toyota. Good luck!