Curing Audio Buzzing ?

[championc]

Hi all

I'm still struggling to solve a buzzing problem. I really need help.

My problem is really simple. WITH THE ENGINE OFF - I have a mini 12v amp connected directly to a NEW connection from the car battery. When I connect my phones' earphone 3.5mm plug to the amp, the sound is perfect - crystal clear. However, the minute I connect my car charger to my phone, I get the following sound. I have tried a ground Loop Isolator between my phone and the mini amp and it makes absolutely no difference.

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[bubbagumper6 5,000+ posts]

Where is the amplifier ground connected to?

 

[championc]

It's connected directly to the battery negative terminal

I ran a new pair of cables directly from the amp (via a relay) back to the battery. That's what has me so confused

 

[Joebobclark 10+ year member]

Its the step down module in the phone charger.... it steps the 12v+ of the vehicle down to the 5v of the phone input... They are cheap components and make alot of electrical noise doing it. Only real way to fix will be try different chargers/inverters until you find one that doesnt have too much noise/buzz, or find a way to isolate the phones ground from its speaker/3.5mm output ground (not going to happen, sorry)...

Maybe a power conditioner type module (something like this, Amazon.com : Pyramid NS12 12 Amp InLine Noise Suppressor : Vehicle Amplifiers : Car Electronics) in the power wire going to the 12v port that you plug the phone charger into.... may at least take some of the buzz out....

 

[championc]

The amp has a USB socket. I tried using this socket to power the phone - with the same result.

I was initially trying all of this with a Wireless Bluetooth 3.0 Audio Adapter Receiver 3.5mm Stereo for Phone Speaker (Wireless Bluetooth 3.0 Audio Adapter Receiver 3.5mm Stereo for Phone Speaker | eBay) and this device is also USB powered.

I bought one of those suppressor type things ages ago. I've no idea as to where I've put it.

Would it work if I bought a Ferrite Choke or Ferrite Beads ? I assume that is what would be inside that supressor you listed ?

Many thanks for your input - it's much appreciated

 

[jeepguylv]

eewwww I say it is the charger for sure, it ***** because the charger I think is sending the buzzing thru the phone's 3.5 jack, I wonder if they make a noise filter for the jack or that cable instead of going thru a ton of different chargers, do you use this because you do not have an aux. jack on your h/u?

 

[jeepguylv]

PAC SNI-1/3.5 Noise Filter Helps eliminate ground loop noise from your portable music player! (3.5mm plugs) at Crutchfield.com have you tried something like this

 

[mrpep]

Look it up on youe tube there is a video on how to get rid of it , it works. Pioneers are notorious for this noise. Basically, you take a ground cable and touch the RCA input and it fixes it. Watch a video on youtube first though, its helpful.

 

[blazian87 10+ year member]

yep, pioneers are notorious for that.

 

[Joebobclark 10+ year member]

The amp has a USB socket. I tried using this socket to power the phone - with the same result.
I was initially trying all of this with a Wireless Bluetooth 3.0 Audio Adapter Receiver 3.5mm Stereo for Phone Speaker (Wireless Bluetooth 3.0 Audio Adapter Receiver 3.5mm Stereo for Phone Speaker | eBay) and this device is also USB powered.

I bought one of those suppressor type things ages ago. I've no idea as to where I've put it.

Would it work if I bought a Ferrite Choke or Ferrite Beads ? I assume that is what would be inside that supressor you listed ?

Many thanks for your input - it's much appreciated

Its the charger that is giving off the electrical noise/buzz, maybe ferrite chokes on the cable from the charger to the phone would help, but you would have to wrap it a few times through the choke... Problem is the charger is giving off the noise and the phone is amplifying it going out the headphone jack... in order to isolate them it would have to be done inside the phone... I have a feeling that the acceptable solution is going to be multiple filters, and the buzz will still be there, just be be very low and hopefully inaudible...

Unfortunately, this isnt a normal ground loop noise, its being introduced from the cheaply made charger (as most are)... I would start with the highest quality charger I could find (or the one that introduces the least amount of noise, may just have to try a few different ones), then add filters from there... Maybe look for a usb isolator as well....

 

[championc]

The h/u is long gone. I decided ages ago to replace it with a CarPC (with RideRunner software) and Touchscreen. Everything is perfect except for the audio. So the system is a PC connected to the AMP which then connects to the original speakers. I did try the RCA trick but no joy.

However, the idea then was to connect the PC to the Amp via the Bluetooth receiver mentioned above so this is why I would end up with a USB powered device connected to the 3.5mm audio.

As stated in the OP, I have already tried the following Ground Loop Isolator without success -

 

[LosIsATool 5,000+ posts]

See if a shop will let you try one first. Most of the time they dont fix the issue.

 

[mrpep]

I've used those in the early 90s and they may be better designed now a days but in my case it helped but did not solve the issue. Try a better ground for turds and giggles. Again, the head units have a lot to do with these issues.

 

---------- Post added at 12:17 PM ---------- Previous post was at 12:16 PM ----------

 

It's connected directly to the battery negative terminal
I ran a new pair of cables directly from the amp (via a relay) back to the battery. That's what has me so confused

A ground cable should be a short run. I never go over 4'. If you are going to the battery it makes me wonder if that is your issue.

 

[hispls 5,000+ posts]

3.5mm cable and phones are both about the worst audio sources you can get. You will always have mediocre results at best if you insist on using either.

 

[championc]

Problem SOLVED !!!

I got a loan of an Identical Bumper Ground Loop Isolator from a friend in work and Bingo, everything was perfect. So I basically had a defective unit