Buzz from laptop

[frenzykitty]

Hi there. I recently decided to finalise my workflow and test out my setup on a PA System. I plugged my laptop into my BCD3000 and UX1 and plugged the UX1 into the PA> There was a terrible hiss/buzz sound. Same issue when I plugged the BCD3000 into the PA.

I unplugged the Charger for my laptop and sound goes away. So what do i do? Worried the battery won't last an entire gig.

[pilmat]

What connection are you using to the PA? My guess is that you might have plugged an unbalanced out from the BCD to a balanced in on the PA.

Also make sure that all the electrical plugs are grounded and not to plug the PA and power supply into the same electrical connection.

Phil.

[DJ_Quickfire]

cut the earth wire out, i know its kinda dangerous, but thats what the problem is by your description, i had the same with my laptop, chopped out the wire and boom was perfect.

[tristancary]

do you have the power supply that came with your laptop or is it different. its probably a bad source of power making line noise. most of the time that happens with ebay chargers etc etc

[frenzykitty]

It's the charger that came with the laptop! Thinking it might be the earth issue. I'm guessing thats why it doesnt happen with mac's, cause they use 2-prong power, whereas mine is a 3-prong to a clover connector.

[Karlos Santos]

This is a simple issue of 'Ground Loop Hum".

If you unplug the power adapter and the hum goes away then it is 100% Group Hum.

It happens in clubs and bars when the DJ booth is on the same ring as things like the beer fridges and air-con.

Some people advise to snap of the earth from the plug. People will say things like "ive been doing it for years" and "an electrician told me" , ive heard it all before. The fact is that cutting of the 3rd prong is fucking stupid and very very dangerous. Should there be a power surge it wont just fuck you up you may end up losing all your Hard Drive date as the current whizzes around you and the laptop.


The simple solution is a Grounds Loop Isolator which cost just a few £s from any electrical store.
Put it between the Soundcard and the mixer and the hum will go.

Click:
http://www.maplin.co.uk/Module.aspx?ModuleNo=33172

[sarasin]

Ground Loop.

Common issue.

Karlos has it above....100%.

[lethal_pizzle]

Yeah Ground Looop. Cutting the earth from the plug is dangerous to people and equipment, and it'll invalidate any insurance yourself or a venue owner may have that would normally cover an incident.

[Str8upDrew]

Get a ground loop isolator man. This is one of the things every body with a PA should have, just like a DI box(unless your PA has both unbalanced and balanced inputs). You won't need these things most of the time, but they're cheap enough to have just incase.

[frenzykitty]

Will this work?

http://www.behringer.com/EN/Products/DI100.aspx