[aceofd1amonds]

Ok, here's what I've got. Please help me troublshoot.
 
I've got my computer plugged into my music hall dac by a cheap usb cable. With itunes paused I'm getting quite a bit of high pitched hiss. If I unplug the usb cable it pretty much goes away. So I deduce that the problem isn't the DAC though I do get some very very low noise that sounds like someone running a sink a couple rooms away - not that big of a deal, but if I could kill that would be a major plus.
 
If I plug my phones directly into the output of my computer via the 1/8" headphone jack I get about the same amount of hiss I get from just the DAC. Same from the Ipod classic.
 
SO, what's the issue? 

 

[JRG1990]

You could try a shielded usb cable?, and what headphones you have low ohm headphones tend to be very sensitive to hiss.

 

[aceofd1amonds]

Ok, I'll try to find a decent shielded cable. This problem was on the JH16 Pro headphones.
 
Anyone else?

 

[endless402]

could be grounding issue
 
1. check if your outlet is grounded properly
2. try a different power cord
3. try a cheater power cord which lifts the ground (power cord which doesnt have a ground). i do warn you that your product wont be grounded, which could be dangerous

 

[JRG1990]

Dont remove the grounding what ever you do, but if you have the dac in the same socket as computer equipment then the interference could be coming though power, you can try a power condition , a shielded power cable with its own ground loop, putting ferrite clamps on your power cables.

 

[batphink]

Plugging the DAC and PC into the same surge protector can also help.

 

[endless402]

try a different source on your dac (plug in a cheap cd player or something)

then you should know if it's a usb or a power plug issue

 

[aceofd1amonds]

Great call on the power cable. The local audiophile shop engineer says to flip the power cable on the computer. I will try these things in a bit right after I get my Apple TV set up as my music server!!
 
Thank you for the help!