MP3 input help......

[venture83_98]

Since my cassette player didn't work, I removed it and installed a MP3 input using the cord from a set of headphones and a switch using the directions found on here. It works great except when I plug in a charger to the player. When I do, I get a repetitive noise/ popping through the speakers on the bike. This happens with the bike running and also with the bike off. It makes the noise when the switch is set for the MP3, or the radio. It also happens with the radio power tuned off. I have the power hooked up to a switched fuse, and grounded directly to the negative on battery. Now for the weird part......If I remove the negative OR positive power wire, It STILL makes the noise...

I have tried with an iPod and a generic mp3 player. Any ideas?

 

Also, the wire for the MP3 is cloth covered. Possible source of noise?

 

This is on my '86 VR

[etcswjoe]

When you say headset cord do you mean you cut one off a pair of headsets? If so I would try a new cord first. Unless it was an expensive set of headphones those cords are not the greatest when it come to repurposing.

[venture83_98]

When you say headset cord do you mean you cut one off a pair of headsets? If so I would try a new cord first. Unless it was an expensive set of headphones those cords are not the greatest when it come to repurposing.

 

 

I was leaning toward that myself. They were a pretty cheap set. Planning on buying a plug at Radio Shack and using "real" wire instead of the tiny wires on most headset cords.

[djh3]

I built a homemade headset for my half helmet after doing some reading up. A fellow did it and used a pair of earbuds for the mic. So I went to the dollar store and got a pair. I can tell you that the little wires in there are about the size of 2 hairs. And to try to solder them was a real PIA. I would say depending on what kind of cord you need try Radio Shack and get one of the larger diameter "extension" cords.

[Guest tx2sturgis]

Ground loop.

 

[etcswjoe]

Ground loop.

 

 

 

Which part of the setup is the likely culprit?

[venture83_98]

I got a much better cord for the input, but no change in the noise. Which is what I expected.

 

Does the shield in the cable from the amp need to be grounded? I just have it twisted together and covered in shrink tubing.

[Barrycuda]

I would try grounding the amp.

[Guest tx2sturgis]

If it plays fine without a charger plugged in, and then makes the whine/hum/buzz when the charger IS plugged in, and the engine is off, its a ground loop problem. If it makes the whine/hum/buzz only when the engine is running, its most likely alternator whine and/or ignition noise.

 

Groundloop:

 

The easiest way to get around this is of course, to use it without a charger.

 

Next easiest is to use a portable charger with the correct adapter cord. You may have to figure out a place to put the charger pack.

 

If you want to try different chargers, some might be filtered better than others...but you might have to buy several different brands to find one that works...not really a good plan.

 

Finally, there are some ground loop 'isolators' available. With some trial and error, you might find something that works.

 

http://www.ebay.com/itm/SNI-1-Mini-3-5MM-Noise-Filter-Ground-Loop-Isolator-Car-Audio-for-iPod-iRiver-/291146614371?pt=LH_DefaultDomain_0&hash=item43c9b0c663

[ame=http://www.amazon.com/PAC-SNI-1-3-5-3-5-mm-Isolator/dp/B001EAQTRI/ref=sr_1_1?s=electronics&ie=UTF8&qid=1400954424&sr=1-1&keywords=audio+ground+loop+isolator]Amazon.com: PAC SNI-1/3.5 3.5-mm Ground Loop Noise Isolator Works with iPod/Zune/iRiver and Others: Electronics@@AMEPARAM@@http://ecx.images-amazon.com/images/I/41IiBYjv7dL.@@AMEPARAM@@41IiBYjv7dL[/ame]

Alternator/ignition noise:

 

Inline 12v filters are available, and you will need to splice into the power wires somewhere in the system to install one.

 

 

Edited May 24, 2014 by tx2sturgis

[dacheedah]

Good bet on ground loop http://www.radioshack.com/product/index.jsp?productId=2062214. You can try a ferrite beads on the supply and ground http://www.radioshack.com/product/index.jsp?productId=3012599 also make sure your spark plugs are resistor plugs.

[MiCarl]

It's a ground loop. Had the identical problem with my GPS.

 

The isolator Tx posted will be the simplest to install.