Ableton Forum

Was really loving my new external Edirol Fa-66 until I plugged in my laptop and out of the monitors
came a horrible static like hum.
Never had this problem with my old soundcard either. The hum is inaudible through my headphones though really loud through
my monitors.
It also works fine when laptop is running off battery.

Please help.

Hi,

that's a known problem and has to do with grounding.

I did run into the same problems with my notebook and got it fixed by changing the power suply to one that doesn't use the euro-connector (with grounding). But if you say, that there is no hum with your old interface and you have no hum while using headphones, I think a DI-Box with ground-lift will do the job. But be careful, because you will probably need that for both in- and outputs.

In my setup al is fine with the special powwer-supply, but when I connect anything to the notebook with grounded power-supply, problems are back. In my case that's my external display in the studio.

I think one of these will fix your problems (if you don't care about the fact that it's Behringer):
http://www.thomann.de/de/behringer_microhd_hd400.htm
http://www.thomann.de/de/behringer_di20_di_box.htm
(The second one will need battery or phantom power!)

If you have further questions, you're welcome to pm me... gerne auch auf Deutsch!

Best,
Christoph

So you think swapping the powerchord for a 2 prong instead of the round style plugwould work?

^ yeah, but an adapter should do it... you don't have to shell out for anything fancy... just a 2 dollar piece from a hardware store.

What adapter?

I'm not a freak in electric circuits, but I think it's not that easy.

When I had this problem first, I read a lot about it. It seems that power supplies without grounding (2pin connection) have another electric design than those with grounding. So just changing the cable or taping the ground contacts will solve the hum-problem but as I read you will probably risk your life by doing so. So I wouldn't do it that way!

And as I described above, it will only work as long as there are no other things with grounding connected via usb/firewire/graphic port or whatever.

Christoph

This is silly. Why was my old soundcard ok?

eggnchips wrote:This is silly. Why was my old soundcard ok?

Just a few further thoughts:
Maybe you changed not only the soundcard but something else in your setup?
What was your old soundcard? (Was it also Firewire ?)
Does the Edirol need an external power-supply or is it powered via Firewire?
Do you still have the old soundcard, so you can check if it appears there too?

This hum things seem always to be strange and my own experience is, that in most cases it was caused by something I totally overlooked.

Good luck,
Christoph

Thanks for your help anyway guys.
My old soundcard is here and working fine without hum.
The only difference is that my old card is Usb whereby the new one is Firewire with power as my laptop only has the 4 pin Firewire port.

I've had this problem with my last 2 laptops. fire-wire soundcard and a cardbus soundcard.

I have a 2 gang mains adaptor which has the earth removed.I plug my laptop adaptor and my external HD in to this. Its only ever plugged in like this when i'm in the studio.

It's probably a bit dodgy but I've been running with this unearthed adaptor for the last 5 years and had no problems. I;ve turned up at gigs, forgotten to bring the unearthed mains adaptor and ended up taping up the earth with electricians tape.

So I've ripped out the ground connections in the socket of my extension chord and it seems to have done the trick.
The humming isn't there anymore when I plug my laptop in. BUT........... what problems can this cause? Is it safe?
As some will say it's dangerous but I see one guy above has done it for 5 years.

Don't disconnect your ground wire. That's dangerous. Your insurance company will be very interested in the event of an accident. Beware.

Just get a ground loop eliminator for about $18 usd.

This connects your outputs to your amp / receiver / PA etc and eliminates the noise.

http://www.bhphotovideo.com/c/product/2 ... Prong.html

My place has the old outlets with no ground. I need these adapters in most of my rooms. I also get the same issue, with a pc laptop with ground wire on the power cord.

I had the same problem. Do NOT remove the groung plug from your power cord or you can fry anything and everything! The answer is one of these pictured below. Plug it into your wall AC outlet and then plug your monitors into it.

eggnchips wrote:So I've ripped out the ground connections in the socket of my extension chord and it seems to have done the trick.
The humming isn't there anymore when I plug my laptop in. BUT........... what problems can this cause? Is it safe?
As some will say it's dangerous but I see one guy above has done it for 5 years.

this is what I was talking about....




I'm not sure what country you're in so maybe the plugs would vary slightly, but with one of these you can test the theory without breaking anything and practically nothing out of pocket. Hardware stores have em by the crate.


The other solutions posted are great. FWIW. I just think that you need to find out what the problem is before you get fancy and spend a chunk of change trying to fix it, what ever "it" is.