HELP! Heavy feedback when laptop charger is plugged in

[The_Blue_Dragon]

Hi people,
Im in deep trouble now, coming upto christmas and Im fully booked. Ive just got back from a 50th Anniversery which before it even started was a disaster.

I set everything up and for some reason I could hear lots of feedback coming from the speakers. I checked everything and unplugged everything one by one and found it to be a problem with the charger.

For some reason when ever the charger is plugged into the laptop it creates loads of feedback. I need to work out whats causing this because I no longer have my reserve laptop because work has asked for it back over xmas.

Anyone got any ideas?

[One Vision]

This is probably one of the most spoken about topics on the forum, "ground loop isolator).
The problem is that laptops, powered external hard drives etc. have only a 2 pin connector, same as your traditional radio lead i.e no direct earth to the plug.
Like I have said probably one of the most talked about subjects on this forum, laptops were never designed to do what they do today so you have to bring them up to date.
To be successful with a laptop setup you HAVE to have a reasonable output source, a headphone socket is just that and not designed for quality output so you NEED an external sound card that has the appropriate outputs.
Again with the power supply its no good for DJ applications so you HAVE to have something to filter the earth problem i.e an earth loop isolator.

You have to use professional equipment for a professional application, so if you want high output, something designed for home use is going to have some kind of issues, either it just wont last the course or other issues just like this.

[The_Blue_Dragon]

Ive never had trouble with it before though thats what confused me

[Grahame Case]

looks like you need to buy yourself an external soundcard for your laptop - i bought one for my laptop - not for DJing - for surround sound, and the audio quality is far superior to the onboard port.

[spin mobile disco]

Do you mean feedback ( a high pitched tone that almost deafens you) or a loud hum that is very annoying?
Just for clarification

[The_Blue_Dragon]

a humming, I thought it was all the same lol. Annoying

[Tony Scott]

Get a ground loop isolator: http://cpc.farnell.com/AV12774/audio-video-tv/product.us0?sku=unbranded-a-1095 ....cost about £5.

Have you changed your mixer/amp/processing or changed any of your cables recently?

[The_Blue_Dragon]

Would one of these be ok?

http://www.ebuyer.com/product/106540

[Sapphire Disco]

I bought 2 from MAPLINS they work fine , you will find them with the car bits just thought I would let you know in case you want them today.

[Woodyo]

If this has never happened before , it may be a dodgy lead connecting your laptop to your mixer , also worth checking all your earth connections on your extension leads as these work loose sometimes.

[Totally Plucked]

Strange for it to start now though if it had been ok previously ?

[Excalibur]

Get a ground loop isolator: http://cpc.farnell.com/AV12774/audio-video-tv/product.us0?sku=unbranded-a-1095 ....cost about £5.

Have you changed your mixer/amp/processing or changed any of your cables recently?


Would one of these be ok?

http://www.ebuyer.com/product/106540

You can't beat having what Tony linked to simply as insurance. The sound card you showed gets good reviews, so I see no probs. This is what I use, and like.
http://cpc.farnell.com/CS16257/computer-products/product.us0?sku=creative-connect
If you prefer to go to Maplis for the GLI, they're a tenner .
http://www.maplin.co.uk/Module.aspx?ModuleNo=33172

[discomobiledj]

I had the same problem last week, got a Ground Loop Isolator, humming stopped. Completely worth the money.

[Totally Plucked]

I'm using the soundblaster card listed and have to say its excellent for the money

[nigelwright7557]

Ive never had trouble with it before though thats what confused me

You could try disconnecting the earth from the power supply plug.
That would prove if its earthing or another problem with the charger.

[501damian501]

You could try disconnecting the earth from the power supply plug.
That would prove if its earthing or another problem with the charger.

no nigel, the earth on eletrical items is their for a reason !

and

you might find alot of laptops have moulded plugs, so you will have to cut the orginal plug off.

[nigelwright7557]

no nigel, the earth on eletrical items is their for a reason !

.

I wasnt suggesting he should leave it disconnected just isolate the problem !

[Excalibur]

You could try disconnecting the earth from the power supply plug.
That would prove if its earthing or another problem with the charger.


no nigel, the earth on eletrical items is their for a reason !

and

you might find alot of laptops have moulded plugs, so you will have to cut the orginal plug off.

Damian is absolutely right on both counts

[nigelwright7557]

Damian is absolutely right on both counts

I never said he wasnt.

I keep forgetting you lads arent fully qualified electronics engineers like me......:D

[Excalibur]

I never said he wasnt.

I keep forgetting you lads arent fully qualified electronics engineers like me......:D

Maybe not, but we know not to advise novices to remove a safety device!:eek:
Sometrimes Nigel you're unbelievable.

[nigelwright7557]

Maybe not, but we know not to advise novices to remove a safety device!:eek:
Sometrimes Nigel you're unbelievable.

Most laptops dont have an earth anyway ! :bang: :bang: :bang: :bang:

[Excalibur]

Most laptops dont have an earth anyway ! :bang: :bang: :bang: :bang:

Irrelevant. The OP didn't know the cause of the problem, so none of us are going to suggest he takes a screwdriver to it. Join the real world mate.

[501damian501]

maybe this will help http://cgi.ebay.co.uk/LAPTOP-ELIMINATOR-GROUND-LOOP-ISOLATOR-PSU-DI-BOX-DISCO_W0QQitemZ380063064284QQcmdZViewItem?hash=ite m380063064284&_trkparms=72%3A12%7C39%3A1%7C66%3A4%7C65%3A12%7C24 0%3A1318&_trksid=p3286.c0.m14

[nigelwright7557]

Irrelevant. The OP didn't know the cause of the problem, so none of us are going to suggest he takes a screwdriver to it. Join the real world mate.

But he would be OK if an expert was helping him !

I am fully qualified unlike you ! :bang:

[501damian501]

Irrelevant. The OP didn't know the cause of the problem, so none of us are going to suggest he takes a screwdriver to it. Join the real world mate.

Diagnosis is allways first...

and nigel i am qualified.

[nigelwright7557]

Diagnosis is allways first...

and nigel i am qualified.

What at ? snotty replies ? :D

[Excalibur]

But he would be OK if an expert was helping him !

I am fully qualified unlike you ! :bang:

Your posts on here often suggest otherwise. If an expert was helping him, he wouldn't be asking on here would he?

[501damian501]

fairground mechanical and electrical engineer

got took short with epilepsy, now am pushing more with my business!

[djsteve10]

Diagnosis is allways first...

and nigel i am qualified.

Well great advise from Nigel there.... :( :( Tamper with the laptop's earth and firstly cost yourself the risk of an electrical failure (Short out ect) and number 2 void the warranty on the laptop.

[nigelwright7557]

who said i was qualified in the electrical side, i do still organise some ride modifications in the winter months, but like i said epilepsy, i dont wish to be playing with machines and get caught in them, as a business side, their isnt much of a market.

you look at the price of some of the machines i need to buy ?

and the staff i need to employ ?

If there are no experts on here then the bloke should be contacting an expert. Sorry that I tried to help, I wont bother again.

[Excalibur]

If there are no experts on here then the bloke should be contacting an expert. Sorry that I tried to help, I wont bother again.

Nigel, more than one of us have given a cure that costs less than a fiver, is advisable in all cases, and doesn't involve a screwwdriver. Why is your suggestion better? Convince me, and I'll apologise.

[Danno13]

I've had to delete a load of pointless posts in this thread. Steve & Damian, If you want to bicker with each other go on MSN or something, don't fill the forum with it.

:ontopic:

Thanks.

[DJ James Lake]

The ground loop isolators are great but what do you use if you use balanced XLR Outputs and want to keep a balanced signal.

Is there something similar available for XLR connections without the need to make up patch leads?

[DJS]

Just buy a Ground-Loop isolator from Maplins.
It does the job perfectly, and is exactly what you need to remove the hum from having your laptop connected to the mains, whilst dj'ing.
I had this same problem with both my laptop, and Roland MC808 Groovebox, and after fitting one to each - job done;)

Scott.

[Danno13]

The ground loop isolators are great but what do you use if you use balanced XLR Outputs and want to keep a balanced signal.

Is there something similar available for XLR connections without the need to make up patch leads?

The ground loop isolater goes between the source (laptop) and the mixer, not the mixer and the amp.

[Corabar Steve]

You could try disconnecting the earth from the power supply plug.
That would prove if its earthing or another problem with the charger.
THIS IS AN EXTREMELY DANGEROUS PRACTICE. DO NOT UNDER ANY CIRCUMSTANCES TRY IT.

no nigel, the earth on eletrical items is their for a reason !

and

you might find alot of laptops have moulded plugs, so you will have to cut the orginal plug off.Indeed


I never said he wasnt.

I keep forgetting you lads arent fully qualified electronics engineers like me......:D
How could we forget, the amount of times that you keep telling us.

Most laptops dont have an earth anyway ! :bang: :bang: :bang: :bang:
Which is why they get earth hums. Are you sure you're a fully qualified electronics engineer?

[sleah]

Which is why they get earth hums.

Not necessarily Steve. Ground loops can be mysterious things, sometimes you need to remove the ground (GLI) and sometimes you need to add a ground (like the extra ground lead on turntables).

However, everyone is absolutley right about not messing with electrical grounds, that should be left to qualified people to deal with.

Occasionally it may be neccesary to alter the electrical ground of a piece of equipment, often when trying to interface consumer/domestic kit with professional kit, but like many other potentially dangerous activities, if you have to ask, you shouldn't be doing it!

[DJS]

Quite funny to see this thread get so serious, and talk of removing earths from mains plugs just amazes me.

As previously said by others and myself, a ground loop isolator is exactly whats needed in this instance.
It fits between the equipment causing the problem (laptop on its mains power etc...) and the mixer and thats it, and best of all, it'll cost you under a tenner for each one.

I had the same problem, and posted this question on a music production forum a while back. The unanimous reply was 'ground loop isolator'.
To prove its not a major problem, my Roland synth gear did exactly the same when on mains power connected to my mixer. Not anymore.

;)

Scott.

[CRAZY K]

THIS IS AN EXTREMELY DANGEROUS PRACTICE. DO NOT UNDER ANY CIRCUMSTANCES TRY IT.
Indeed


How could we forget, the amount of times that you keep telling us.

Which is why they get earth hums. Are you sure you're a fully qualified electronics engineer?

I think Nigel in his defence is talking about procedures which would be carried out in the safety of a workshop by qualified experienced engineers who can safely carry out procedures which might seem to be dangerous to the general public--but are perfectly safe and harmless in controlled conditions where people who know their business operate.

I think the reality is a lot of these problems potentially involving killer electricity would be best solved by popping down to your local DJ repair shop for help--thats what I did when I got a hum with my Cortex and hard drive.

That would be my advice.

CRAZY K

[Corabar Steve]

Apart from the fact that any modification would void any remaining warranty, equipment is designed the way it is for a reason. The PSU is designed to match the equipment that it's sold with.

[CRAZY K]

Apart from the fact that any modification would void any remaining warranty, equipment is designed the way it is for a reason. The PSU is designed to match the equipment that it's sold with.

Agreed, the one thing that doesnt add up is why the hum has started suddenly.

If it was there from the day of purchase then thats easily solved---which happened with my Cortex.

But if it starts suddenly out the blue then its different, a point some people have missed.

If theres an Xmas residency to do, pay for proper professional help and get it sorted--its tax deductible--as Rob would say:D :D :D

CRAZY K

[sleah]

Agreed, the one thing that doesnt add up is why the hum has started suddenly.


Could be caused by a poor earth connection in an extension block or supply socket, or possibly a tarnished audio cable. Or even it was a poor connection somewhere before, that's now OK.
No point in dweling on it mate! Audio can be a funny old thing when it wants to.

Only recently setting up PA at work, I had a hum which came and went as it felt like it:confused: Probably a tarnished connection like I've mentioned.

[nigelwright7557]

Anyone got any ideas?

When gigging do you use two extension leads ?
Its possible the two extensions could be on different phases of the mains.
If possible always keep all your audio on the same extension lead.

[Excalibur]

When gigging do you use two extension leads ?
Its possible the two extensions could be on different phases of the mains.
If possible always keep all your audio on the same extension lead.

Highly unlikely if both extensions are in the same twin wall socket Nigel. ;)

[nigelwright7557]

But possible if playing in a large hall.

[sleah]

When gigging do you use two extension leads ?
Its possible the two extensions could be on different phases of the mains.
If possible always keep all your audio on the same extension lead.
Or at least on the same phase!


Highly unlikely if both extensions are in the same twin wall socket Nigel. ;)

LOL:D smart a$$:D


But possible if playing in a large hall.

Exactly. Especially since the abolition of the 2m rule, where sockets on different phases had to be at least 2m apart, that doesn't apply any more.
So in a relativley new build, it could be possible to find a stage mains board with say 3 twin 13a sockets on 3 different phases.