Help! Humming/Radio Interference - Powered Speaker

[Syncretia]

I'm just using headphones.

But, how would you get sound from a sound source without connecting it. Sorry, very confused about the post above.

[Patech]

I'm just using headphones.

But, how would you get sound from a sound source without connecting it. Sorry, very confused about the post above.

SORRY...
I was replying to the original post.

[Syncretia]

Will somebody please help me for the love of god!!!!!

OK. I ended up taking the damn thing to the store, swapped it for a new one and I've got the same problem. Perhaps slightly less... Not sure.

So I have tried this on three freaking computers now. Mac Minit, PC Laptop, PC Dekstop - the same problem in all of them. And the same problem at the store with professional balanced monitors.

I'm at the point now where I don't believe it's anything other than a design flaw of the interface. What else could it possibly be?

[Karlos Santos]

a ground loop isolator doesnt solve the problem, ground loops are usually caused by faulty laptop power packs

Not true... Group loop isolators work in lots of cases especially when the load on the mains ring is heavy from things like the Bar/clubs fridges.
I have first hand experience of this and my power bricks are fine.

Also:
Where are you DJing..?

Do you have Energy Saving bulbs in your lamp/lights..?

Do you have them on a dimmer switch..?

Energy saving bulbs cannot always be dimmed and when they are dimmer they cause terrible mains hum.

[Syncretia]

Where are you DJing..?

This problem occurs at home and it also occured at the store where I bought the interface. It also happens in many rooms in my house (laundry for example). It also occurs when I unplug the power sometimes. However, since I exchanged the box, I can't recreate the noise when I unplug the power altogether.

Do you have Energy Saving bulbs in your lamp/lights..?

Do you have them on a dimmer switch..?

No, and No.

I have tried turning everything in the house off (fridges, other computers, lights, TV, etc.). The problem still occurs.

I have tried this on three separate computers. The only time I don't get the hum at the moment is when I plug it in to my laptop and there is no power connected. But, remember that with the older box (before I swapped it), it used to hum even when there was no power plugged in.

[Audeo]

This is what DI boxes are for. The real cheap ones (good enough for home use) go for about 40 euro's here, US being cheaper with most tech, I guess you can pick one up at Guitar Centre for a few bucks.

Be sure to ask for a stereo DI box. TRS from the soundcard goes in, turn on ground-lift and plug the XLR in its output and in the powered speaker.

[Syncretia]

Buh?

Call me ignorant but what does a DI box have to do with this?

I'm not recording from an external source. This is not on the recording side.

Basically, when I turn my saffire on and hook it up to my stereo or earplugs, it hums like a $2 hooker.

How would a DI box solve this?

[ellgieff]

Buh?

Call me ignorant but what does a DI box have to do with this?

I'm not recording from an external source. This is not on the recording side.

Basically, when I turn my saffire on and hook it up to my stereo or earplugs, it hums like a $2 hooker.

How would a DI box solve this?

He's assuming it's a 50cycle (60cycle in the US?) hum from a ground loop. A DI with a ground-lift is likely to sort that kind of problem right out.

[Syncretia]

I'm considering buying a ground lifter just to finally put to rest the idea that this could be caused by a ground looping problem but before I do, I have tried this:

-Laptop connected to power
-Saffire connected to laptop
-Earplugs connected to saffire

The problem still occurs.

Doesn't a ground loop only occur when 2 or more power sources are connected?

Anyway, please explain how I could solve this problem with a DI box. Remember, this is the setup:

PC-(USB)>Saffire-(RCA)>Analog Receiver-(Speaker Cable)>Speakers

Where would I put the DI box in this chain?

[Syncretia]

Oh my #@$@ing god!!!

For @#$@'s sake!

I have a gig on Friday night. I set all my shit up with my laptop and it is humming like a mother@#$#er! Jesus! WTF?

This thing is humming so #$@ing bad, it's going to embaress the $@#$ out of me.

@#$# Focusrite!