Feedback from Amp/Speakers when plugged into laptop

[thomas]

This never used to happen, until I swapped my AMP. The old one went wrong and it was swapped for the same model.

Basically, when I plug the 3mm jack into my laptop the speakers play a load of awful feedback (and the sounds from the laptop underneath). If I unplug the power cable for the laptop then the feedback goes.

I've tried plugging my laptop into different plugs and things, through a fused extension cable, etc...and still having the same problem. I changed the input, input cable, etc...same problem ..

Anyone got any ideas on how to fix it?

 

[Dan B]

Does your laptop have an internal microphone? May be worth fidding with its mixer application to see if that's been toggled on

 

[thomas]

Does your laptop have an internal microphone? May be worth fidding with its mixer application to see if that's been toggled on

None, not done anything.

I should mention. it doesn't matter what input the AMP is set to. Even if it's not the same as the laptop is on, it will still screech. It will only screech if the laptop has the power cable plugged in (no noise, when running on battery).

Laptop doesn't do it when plugged into computer speakers.

my DAB radio works fine, and that's plugged into the mains (even when in the same slot as the laptop).

 

[Candaules]

It could be an earthing fault. I had a similar problem when connecting a desktop PC to a stereo amp. I fixed it by adding a 'ground loop isolator' like this one:

http://www.maplin.co.uk/Module.aspx?ModuleNo=226569&C=Froogle&U=226569&T=Module

The one I bought (also from Maplins) was much cheaper, but it did the job.

 

[Milo]

An earth fault sounds most likely to me.

 

[thomas]

It could be an earthing fault. I had a similar problem when connecting a desktop PC to a stereo amp. I fixed it by adding a 'ground loop isolator' like this one:

http://www.maplin.co.uk/Module.aspx?ModuleNo=226569&C=Froogle&U=226569&T=Module

The one I bought (also from Maplins) was much cheaper, but it did the job.

An earth fault sounds most likely to me.

Cheers guys! I was expecting there would be some little accessory I could place in between, but no idea what it was. Might have a look on ebay/on other shops for something a bit cheaper, but it sounds like it's worth a gamble

edit:
Does this one look okay?

http://www.amazon.co.uk/GROUND-ISOL...WB9O/ref=sr_1_1?ie=UTF8&qid=1269515337&sr=1-1

 

[Candaules]

The one you've found on amazon looks just like the one I bought from Maplins. It should be fine (assuming you do have an earthing problem.)

 

[thomas]

The one you've found on amazon looks just like the one I bought from Maplins. It should be fine (assuming you do have an earthing problem.)

Excellent. I ordered the same one off ebay for £3.70, so even if it doesn't fix it it hasn't cost me you much.

Hopefully it'll come early next week so I'll let you know! Finger's crossed

 

[thomas]

Worked Cheers guys!!