Try adding a ground loop isolator into the audio cable. They can't be bought just about anywhere (Amazon, Radio Shack, etc.) for about $15 and should eliminate and ground loop noise. Ground loop noise is why it is so hard to find a car dock that includes audio out. Companies understand consumers want a car dock with 3.5mm audio out but wouldn't be able to design a dock that would eliminate noise in every case.

Filtering the audio line with a ground loop isolator is not a solution for me. They often dramatically reduce high tones and degrade audio quality overall. A real solution is to solve the issue on the electrical side, not the audio side.

OK, I think I understand what you are saying now. I get the normal ground loop whine that I have always gotten in my truck, that changes pitch with RPMs. Known issue with all phones in my truck, whatever.

But today I also noticed a Static (1 second) Static (1 second) Static (1 second) Static (1 second) that was only noticable when my phone was in the dock, plugged in, no music playing (in between songs) AND the beats audio logo was visible (beats was off, I do not use it). Beats logo goes away (when there is more than a second or two of silence) and the static stops. I'm not sure if the static is stopping then because the beats signal processor is turning off, or because the phone is turning off power to the headphone jack. If it is the beats processor turning off, I could try to make a mod to always keep it off (I don't use it anyway).

Is anyone seeing this static (static, not whine) while plugged in but NOT in the dock?

Is this what the OP is seeing? How about the rest of you?

Originally Posted by modplan

OK, I think I understand what you are saying now. I get the normal ground loop whine that I have always gotten in my truck, that changes pitch with RPMs. Known issue with all phones in my truck, whatever.

But today I also noticed a Static (1 second) Static (1 second) Static (1 second) Static (1 second) that was only noticable when my phone was in the dock, plugged in, no music playing (in between songs) AND the beats audio logo was visible (beats was off, I do not use it). Beats logo goes away (when there is more than a second or two of silence) and the static stops. I'm not sure if the static is stopping then because the beats signal processor is turning off, or because the phone is turning off power to the headphone jack. If it is the beats processor turning off, I could try to make a mod to always keep it off (I don't use it anyway).

Is anyone seeing this static (static, not whine) while plugged in but NOT in the dock?

Is this what the OP is seeing? How about the rest of you?

I am not the OP but I am getting the exact same results that you are. It sounds perfect when not in the dock. When in the dock it makes a terrible buzzing noise until I start to play something. I have tried multiple chargers including OEM HTC ones in multiple vehicles and the problem still persists. How can ground loop be non existent when I'm charging my phone with just the cable (outside of the dock)? It has to be something else. I ordered the HTC Stereoclip yesterday and should have it be the end of this week to test wireless play.

Originally Posted by willyam111

Try adding a ground loop isolator into the audio cable.

I already had one installed for my Epic, and still get the noise on my EVO....

Just out of interest, is the 3.5mm jack going into the Phone, or is it tied into the charger cable. I currently have a MOTO Atrix and the Car Dock USB Cable splits off with an Aux Jack connection. That way you don't need to keep plugging the Aux Cable into the phone everytime you dock. I've never had any interference with this approach.

I'm getting the EVOLTE as soon as possible, so I'm interested in this answer. Plus, how it's being connected may be part of the problem?

Originally Posted by csyrell

Just out of interest, is the 3.5mm jack going into the Phone, or is it tied into the charger cable. I currently have a MOTO Atrix and the Car Dock USB Cable splits off with an Aux Jack connection. That way you don't need to keep plugging the Aux Cable into the phone everytime you dock. I've never had any interference with this approach.

I'm getting the EVOLTE as soon as possible, so I'm interested in this answer. Plus, how it's being connected may be part of the problem?

There is no audio jack coming out of the dock. You still have to use the one on the phone itself.

So I took apart the dock and there is one small chip inside. Seems like a lot for what should just be usb passthrough. I tried removing the blue led hoping that that was the cause of the interference but it did not help.

There are lots of resistors and capacitors on this board. Does anyone know of we remove them all it will be straight usb passthrough? I get MUCH less interference in my truck with just charging and NOT the dock using the same cable. I good way to test this is to turn the Media volume all the way down on your phone and up high in ur vehicle and you will get tons of static and popping.

Any electrical engineers in the crowd? I if not I guess I have to buy a stereo clip :(

Sent from my EVO using XDA

Those electronics are probably what activate Car Mode.

Originally Posted by ahecht

Those electronics are probably what activate Car Mode.

Activating car mode is done my simply shorting pins 4 and 5 on the USB connector, no electronics required and is why the dock will still put your phone into car mode when not even plugged in.