Stopping hum/interference between laptop and PA System/speakers.

raindog.promo

Hey folks,

I've been trying to sort out this problem for a while. Basically, you plug a laptop into a PA system and it causes interference noise to come out of the speakers. Pull the power supply from the laptop (so it runs on the battery) and it stops. Not an ideal solution.

So I've been looking into it and have come across 2 answers so far.
One is a ground loop isolator. I understand ground loop problems but have no idea what this isolator thing is or looks like.

The other is a line isolation box which fits between the external soundcard and PA system such as this:
http://www.musicstore.de/en_EN/IEP/Palmer-PLI-03-Line-Isolation-Box-2-Channel/art-REC0001738-000

Can anyone recommend any other fixes, or which of the above is better and is it possible to get this equipment in Dublin (I'm sick waiting for German music store deliveries!)?

Any help/advice appreciated.

Thanks.

trackmixstudio

Art DTI should do the job.
http://www.thomann.de/ie/art_dti.htm

raindog.promo

Cheers.
Any idea if I could get one in Dublin?

studiorat

Most DI boxes would sort it out I reckon.

http://www.diy-central.com/DIYTransformerBasedUnbalancedToBalancedsignalIsolationBox.aspx


try adverts.ie

raindog.promo

studiorat wrote: »

Most DI boxes would sort it out I reckon.

http://www.diy-central.com/DIYTransformerBasedUnbalancedToBalancedsignalIsolationBox.aspx

Very scary looking page.

All my electronic projects are half finished.
Even if they were finished, the constant worry of them somehow causing my death would play on my nerves too much

old gregg

A DI box as suggested by studiorat will solve it for sure. In my case I sometimes get the same problem at gigs and if they have a DI box then it's fine. If not then I always keep a Carpower Ground isolator in my gig bag. Something like this puppy: http://www.juno.co.uk/products/carpower-fag40hq-ground-loop-isolator/411779-01/

If memory serves, it cost me around 20 eurines in the music/dj shop in Capel st., Dublin. Used it all over the place and always works.

raindog.promo

old gregg wrote: »

A DI box as suggested by studiorat will solve it for sure. In my case I sometimes get the same problem at gigs and if they have a DI box then it's fine. If not then I always keep a Carpower Ground isolator in my gig bag. Something like this puppy: http://www.juno.co.uk/products/carpower-fag40hq-ground-loop-isolator/411779-01/

If memory serves, it cost me around 20 eurines in the music/dj shop in Capel st., Dublin. Used it all over the place and always works.

Cheers, would that shop be Sounds Around by any chance?

http://www.soundsaround.ie/

old gregg

raindog.promo wrote: »

Cheers, would that shop be Sounds Around by any chance?

http://www.soundsaround.ie/

Indeed it would. Only in Dublin every few months so couldn't remember the name.

raindog.promo

Thanks. Much appreciated.

*edit* Just rang and checked. They have ground loop isolators in stock for €19.99