Giso Grimm wrote:
Hi,
On 04/07/2011 12:34 AM, Dave Phillips wrote:
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).
we observed exactly the same problem (only on the output of a custom
made USB sound card). The noise was spikes of varying amplitude at a
fixed rate (125ms if I remember well). Replacing the USB cable by a
shorter one significantly reduced the problem, and it also depended on
the USB ports used for mouse and sound card. On some mainboards/laptops
the noise was less then on others.
Also depends on the presence or absence of an externally-powered
external USB hub. I have an external USB2 hub (having three USB ports on
laptop and 8 devices to plug into them). Running my USB soundcard
through the external hub provided large bundles of noise. Hooking it
directly to a USB port on the laptop abolished the noise. Probably bad
grounding in the external hub or its power supply.
--
David
gnome@xxxxxxxxxxxxx
authenticity, honesty, community
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user@xxxxxxxxxxxxxxxxxxxx
http://lists.linuxaudio.org/listinfo/linux-audio-user
