Noise!

[JFraser]

Hi all,

 

I'm aware there have been other threads on this but have already tried other 'solutions' but to no avail so I thought I'd start my own thread specific to me.

 

I'm getting noise coming through my speakers and I think it must be EMI/RFI as the noise is related to activities like moving my mouse.

 

My PC is custom built with a very small case, which I fear might be the problem with all the components packed close together but I could be wrong of course. See parts list here.

 

My DAC is an Arcam rPAC and I have an unbalanced passive volume control between the rPAC and my speakers (KRK VXT6 monitors w. KRK 10s sub).

 

All I have connected to the PC is a keyboard, mouse, webcam and the DAC of course.

 

The noise seems to be worst when the passive volume control is around the middle for some reason.

 

After doing my own research, I think getting a USB isolator might be the best choice but before buying it, I'd appreciate anyone's input who has had experience with these!

 

Pretty simple set up. Hopefully someone can help me out

[Nikhil]

Your PC itself is a major source of noise primarily due to the SMPS (power supply). There can be other issues in your setup but the PC power supply is the first place to start. If you are using a laptop then the power brick is a notorious source of noise for audio.

 

A good linear power supply would be an ideal solution. TeraDak are HDPlex two good suppliers to consider and there are many threads on here discussing their merits. USB isolation solutions will help reduce a lot of noise that travels via the USB cable to your DAC but there is still noise that is injected into the mains from the PC SMPS.

 

Hope this helps.

[ilok]

Noise from moving the mouse is a grounding problem, you might also hear CPU usage noise too. I had this problem when using HDPlex's linear power supply. Make sure your PC is grounded (and that your ground is actually grounded, eg bonded to neutral only at the main service entrance, and that your ground rod is connected to the ground, make sure neutral and ground wires are not swapped, etc, you may or may not need an electrician's help here)

[goohsm]

I have the exact same problem with Sony pha3 with active speakers but absolutely no noise with headphones

I assume that it's because sony pha3 is originally made for headphone amp

 

desktop powered + usb -> noise

adapter powered + usb -> noise

desktop powered + toslink -> noise

adapter powered + toslink -> no noise

 

notebook plugged -> noise

notebook on battery -> no noise

 

would balanced connection solve the problem? because both pha3 and my active speakers support balanced input output

 

I could imagine my noise is what they call RFI and I think the noise very related to mouse, keyboard interactions and graphics card

[ilok]

delete

[MG32]

Try a USB line conditioner and/or a USB power supply that injects clean power, not from the PC.

 

Try hooking up the USB directly to the motherboard and not on the PC's front ports.

 

MG32!