[APoL0]

Hello everyone. A few days ago I bought a new computer. To this new computer I plugged in an Asus Xonar D2 by PCI from my old computer. To this card I have connected the amplifier LD MKIII to which I have connected a Sennheiser HD 595. It turns out that something strange happens now that did not happen with the old PC. When I'm not playing anything, simply move the mouse slightly it sounds a little noise interference as a "bzzzzz". This noise increases when the GPU load increases (one Gigabyte GTX 770 OC 4GB). Testing for example Crysis 3, the noise was really annoying. I tried to connect the amplifier directly to the motherboard and the noise was still there. I tried also to connect the headphones directly to the sound card and directly to the motherboard and the noise disappeared. The problem is the amplifier, but with the old PC this did not happen.

 

[Jd007]

Ground loop problem. I had the exact same issue. See here for more details: http://www.head-fi.org/t/670231/very-weird-problem-sound-card-interference-with-graphics-card-only-when-line-out-to-external-amp

 

[APoL0]

Ok thanks for the help. I've been searching and I found this:
 
http://www.ebay.es/itm/Ground-Loop-Isolator-Hum-Filter-DJ-PA-Laptop-Car-Audio-01187-/370846610601?pt=UK_Sound_Vision_Cables_Leads_Connectors&hash=item56582e34a9
 
This gonna connected directly to the RCA of the amp?

 

[HPiper]

For some reason LD amps have some kind of a grounding problem, luckily I haven't had any trouble but I know a couple people who have.

 

[lemonjelly]

I have a LD mkiii and had similar problems when I tried directly connecting from my xonar dx/onboard to the amp.  I've had a few different systems and the interference would be better/worse randomly, but normally there to some extent.  As you found direct to headphones had no interference.
 
For me I already had a yulong d100 DAC before I got the amp, so I just use that and have no problems.  I found with that through USB I sometimes had a little bit of interference, but that on 2 of my last 3 mobos I could find a port that didn't have any.  And using optical I have no problems whatsoever, which is what I use atm.
 
All that is with the mkiii connected of course - no interference at all when just using the d100 so it seems like it is something specific to the LD.  Maybe an option if you fancy a new DAC anyway !

 

[xxAMAROKxx]

I solved this interference noise by easy hack:
Inside Little Dot II is yellow ground cable screwed to the case. Disconnect it with srewdriver and isolate thoroughly with electrical tape. And that is all. Noise is gone.
(You do it at your own risk)