Gounding Problem

[stanton119]

Im getting a lot of noise through my speaker from my iPod. The mixer is connected to a different wall socket than the iPod. I think the problem is a ground loop. What can I do to solve this?

Would this work??
[url="http://www.maplin.co.uk/Module.aspx?ModuleNo=33172&C=Froogle&U=33172&T=Product&MA=Ground%20Loop%20Isolator%20(Ground%20Loop%20Isolator)"]http://www.maplin.co.uk/Module.aspx?Module...oop%20Isolator)[/url]

[BOD2]

[quote name='stanton119' post='7028' date='May 26 2007, 10:21 AM']Im getting a lot of noise through my speaker from my iPod. The mixer is connected to a different wall socket than the iPod. I think the problem is a ground loop.[/quote]


Can you connect both to the same wall socket to see if this eliminates the problem first ?

Also check the "pinned" notice above about humming and buzzing to see if anything mentioned there might help.

[nedsbeds]

What happens if you unplug the power from the ipod?

[stanton119]

I cant attach them to the same outlet, as they are on different sides of the room, and the cables connecting them are fixed in place. Im not sure its the ipod. There is always a certain amount of noise from it, by when playing videos through the TV (which is also connected to the mixer, but not turned up) there is very loud noise. This also happens when my bass amp is connected to the alt out. It is also connected to a different outlet. When it is unplugged, there is no noise.

[Bill Fitzmaurice]

[quote name='BOD2' post='7039' date='May 26 2007, 05:56 AM']Can you connect both to the same wall socket to see if this eliminates the problem first ?[/quote]
Even then the ground loop may persist, as there will still be two ground paths connecting the devices. Transformer isolation is the best bet for a cure.

[BOD2]

I don't think that maplin module would help. It's a filter designed to remove "ignition noise" in a car installation. That's quite different to ground hum.

This could be quite tricky to resolve. It's unlikely to be wall socket (I was suggesting you try that because I thought it would be relatively simply to try) and, as Bill points out, that wouldn't necessarily solve the problem.

The transformer isolation Bill suggests should cure the problem but it might be tricky to obtain what you'd need and you'd still need to identify where to put it.


Can you disconnect everything that reconnect the items, one at a time, and identify at what point the noise starts. That might help identify which device is creating the problem. Also, if you can connect things up in a different order check to see if the noise again starts when the same devicve is connected.

Switch off the TV. Does the noise stop when the TV is off ? (TV screens can be very bad at generating noise that is then picked up by other equioment).

Is all the equipment positioned very close together ? In particular - is it all close to the TV ? Try moving the mixer further away or even (if you can) pick up the mixer while everything is switched on and move it around and rotate it a little. Sometimes moving equipment out of the electrical field of other equipment can help.

Are there any wall wart power supplies close by ? Try moving things away from these to see if this helps.


This advice might not seem very scientific but sometimes repositioning equipment is enough to reduce the noise to an acceptable level.

[stanton119]

I bought one of those ground loop isolators, and the noise has now gone.
Thanks everyone for your help.