[LAU] UA25 noise problem w. nVidia chipset

[Arnold Krille]

On Thursday 07 April 2011 00:34:03 Dave Phillips wrote:
> Greetings,
> 
> I've been working with Ardour3 on my laptop, a machine with an AMD
> Turion X2 CPU and an nVidia 8200M integrated video chipset. Recently I
> started monitoring my test recordings through the headphone output of my
> UA25 and I notice that when I move the mouse it creates scratchy sounds,
> though QJackCtl reports no xruns and my recordings are unaffected. I
> verified the problem with Ardour2 and Mixbus. It doesn't occur when I
> use the integrate audio chipset (snd-hda-intel, wahoo).

This is clearly an analogue problem. As both the mouse and the ua25 share the 
same power and earth and don't provide any sophisticated main-filtering or 
shielding, you are bound to get such problems.
Probably the noise doesn't occure when you use the touchpad.
Does the ua25 come with a power-adaptor? Could be that removes the noise.
Another more hackish thing to try is to make an extra usb-cable where the 
data-lines go through but Vcc and maybe even GND are disconnected and the 
power is feed from an external source.

Have fun,

Arnold
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