Ground Loop Issues :O

Cutting the ground will help, putting everything on the same surge protector should help. Pick your poison.

As far as non-grounded, back when I hadn't realized the incompetent who wired this house didn't connect the ground wires to the outlets, my pc case had a charge in it that could make a noise if I touched headphones to it, but it never seemed to adversely affect anything. Honestly grounding is mostly about safety.

You need a ground loop isolator.  Xitel's product page does a pretty good job of explaining what ground loops are and what causes them.  The reason why you've never has this problem with your laptop is because laptops use far less power (less than 20 watts) than desktops (more than 350 watts).

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=265-012

^ much more sane price than Xitel's product.

Ground loop isolators aren't a fix, they're a workaround.

you need an ADuM4160 dongle, it will provide USB galvanic isolation.

Quote:

Originally Posted by MKHTTJ 

Hey guys, I have a serious ground loop issue I cant figure out

 

I run audio from my PC through a USB DAC (powered by the usb cable) to an MKIII Little Dot headphone amp (with its own power cable) and then to my Grado RS-1's.  Unfortunately theres an incredibly annoying buzzing sound that I can't get rid of, even if i turn the amp off.  I never had this problem on my laptop and I can't figure out what to do :/

 

I won't pretend to completely understand how ground loops work but I was hoping someone could give me some productive (and safe) advice on how to fix the problem.  I've heard of just cutting off the third prong on the power cable but that sounds like a bad idea so..... I'm asking you guys lol

 

edit: also the buzzing sound gets louder if i turn up the volume on the amp so I assume the problem begins with my pc if that helps

Yes cutting off the ground plug is for idiots...or rather dead idiots.  The groiund is there for a reason to keep you from getting fried.  If you removed the ground an stray electricity will go right into you instead of the ground.  Try and put everything on the same power circuit, this should fix the trouble.  If not then perhaps your issue is elswhere.

There is an important distinction between disconnecting a ground pin vs a device that is made without a ground pin. Devices that don't have a ground pin are required to be Class II insulated (double insulated) preventing the possibility that a deadly shock can reach the user. Disconnecting an existing ground pin means that you are removing the safety ground from a Class I insulated device and isn't recommended.

The safety ground is there to prevent the worst case scenario of line voltage reaching the user. I don't think you can overstate the importance of preventing the possibility of that happening.

Quote:

Originally Posted by Nebby 

There is an important distinction between disconnecting a ground pin vs a device that is made without a ground pin. Devices that don't have a ground pin are required to be Class II insulated (double insulated) preventing the possibility that a deadly shock can reach the user. Disconnecting an existing ground pin means that you are removing the safety ground from a Class I insulated device and isn't recommended.

 

The safety ground is there to prevent the worst case scenario of line voltage reaching the user. I don't think you can overstate the importance of preventing the possibility of that happening.

Exactly.  Thank you.

Not to mention the guy already dismissed the idea and wants only SAFE advice.

Great you got it fixed.  Enjoy.