I heard a hum/static through my monitors and headphones when using my Firepod... After a while, I eventually traced the problem to the power adaptor for my Laptop. When plugged in, there is a hum, and when not plugged in there isn't. This must be due to the ground... therefore, I'm trying to figure out the best way to solve this problem. I know that Ground lifting is generally dangerous and not recommended. IF anyone has a tip on how to keep my computer plugged in and to eliminate this hum from the adaptor (ground) that would be helpful. Thanks.
Comments
JCarlo wrote: Some ideas: Plug the power adaptor to different a
JCarlo wrote: Some ideas:
Plug the power adaptor to different ac outlet than the rest of your gear.
Turn the power adaptor 180 degrees and replug it. Sometimes it works.
Use a good UPS and plug your laptop's power adaptor to the battery bakup outlets. You should do this anyway.
Try Ebtech's hum eliminator.
Try a balanced power supply.
I tried plugging it into my power conditioner and my regular surge protector, and I still go the same hum.
I turned the power adaptor - doesn't do anything.
What is a UPS? I can only think of "universal power supply". How do you plug the adaptor to the battery backup outlets?
I'll look into the Ebtech.
Please elaborate on a balanced power supply.
I'm still new to DAW recording, so forgive me for my ignorance on some of your suggestions.
Thanks!
It might be the switching power supply in your computer, which c
It might be the switching power supply in your computer, which can cause a lot of trouble in the audio band.
Here is some useful background info:
http://www.epanorama.net/documents/groundloop/home_solving.html
I believe the Firepod is not connected to earth; does it have a wall wart transformer with only 2 prongs?
Does you laptop power supply have an earth connection (2 prongs or 3?)?
Do the monitors have an earth connection?
Here is a line isolation transformer (best solution):
http://www.hammondmfg.com/171.htm
This will isolate your PC from the other circuits.
or this -which may not be as good but much cheaper: HUMplug-e
http://www.21best.com/21_best/electronic/security/video/filters/for_sale_.html
Best of luck.
Link555 wrote: It might be the switching power supply in your co
Link555 wrote: It might be the switching power supply in your computer, which can cause a lot of trouble in the audio band.
Here is some useful background info:
http://www.epanorama.net/documents/groundloop/home_solving.htmlI believe the Firepod is not connected to earth; does it have a wall wart transformer with only 2 prongs?
Does you laptop power supply have an earth connection (2 prongs or 3?)?
Do the monitors have an earth connection?
Here is a line isolation transformer (best solution):
http://www.hammondmfg.com/171.htm
This will isolate your PC from the other circuits.or this -which may not be as good but much cheaper: HUMplug-e
http://www.21best.com/21_best/electronic/security/video/filters/for_sale_.html
The HUMplug-e is what I would need. The first one (isolation transformer) looks good, but a little bulky... it would be a pain to carry around with my portable DAW. Also, I can't seem to find a price on that one (unless I called).
To answer your questions:
The firepod is not a wall-wart. It is a 2-prong "central station" power supply seen here: http://images.google.com/imgres?imgurl=http://www.presonus.com/store/images/PSfirepod.gif&imgrefurl=http://www.presonus.com/store/index.php%3FcPath%3D28&h=68&w=73&sz=3&hl=en&start=6&um=1&tbnid=rtZJnFHZMPaFZM:&tbnh=65&tbnw=70&prev=/images%3Fq%3Dfirepod%2Bpower%2Bsupply%26svnum%3D10%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26sa%3DG
My laptop power supply is a ground connection (3 prong).
My studio monitors are both 3-prong (however they are not the problem - only the laptop creates the ground loop when plugged in).
Thanks.
Link555 wrote: Thanks Ardroth, Ok so the firepod has a floating
Link555 wrote: Thanks Ardroth,
Ok so the firepod has a floating chassis. Which mean there is no earth connection, IE no third center prong.All and all I think the HUMplug-e, should work, but if doesn't the Hammond iso-transformer will.
Yeah, I agree... I ordered the Ebtech HUM-X from Amazon.com for $60... hopefully it will solve my problem. Thanks for the help man.
Some ideas: Plug the power adaptor to different ac outlet than
Some ideas:
Plug the power adaptor to different ac outlet than the rest of your gear.
Turn the power adaptor 180 degrees and replug it. Sometimes it works.
Use a good UPS and plug your laptop's power adaptor to the battery bakup outlets. You should do this anyway.
Try Ebtech's hum eliminator.
Try a balanced power supply.