I would be very grateful if somebody could give me some pointers here.

I'm trying to run an USB sound card (Sound Blaster Live! 24-bit) with my HP Omnibook xe 4100 laptop. Things work fine except for the microphone. When trying to record sound or use Skype, I get a constant loud, hissing noise whenever the microphone (or any plug, for that matter) is plugged in the sound card's microphone socket.

The card vendor has tested the card and claims that it's in perfect condition. They maintain the problem is that the onboard sound chipset in my laptop keeps interfering with the SB card, even though I've disabled it in the Device Manager. That's all I can do, since it seems it's not possible to disable onboard sound from BIOS in the Omnibook xe 4100.

It would be really nice to get some opinions on this. Is it really possible that the problem lies with my onboard sound chip set, and is there no way to turn the thing off?

I've combed the web but I haven't come up with anyone else having the same problem, which would suggest it's not a regular hardware condition.

The Creative e-mail support seems to be only good for kindergarten level advise, "try to set the mic-in level right" etc.

This is just a best guess secnario:

Is the microphone plug mono while the input jack is stereo?

In the Volume Control properties,have you selcted the new card as the "preferred device"?

You might try turning off (by unchecking, you mute) all other input sources except the microphone and see if there is any improvement.

Thanks, Lobster Boy

In fact I have two microphones, a dynamic and an electret, and both have stereo plugs (stereo is the one with 3 metal contact bands, right?). Both have exactly the same problem.

And yes, I have the SB as my preferred device, it seems Windows does that automatically when there's no other sound devices enabled.

Muting other input does not do the trick, but there is one mystifying effect I have discovered. Whenever I'm monitoring a recording -- i.e. I have Enable Monitoring checked, so I hear in the headphones what the mike is picking up -- the hiss is killed in the headphones, if I mute the Line-In control. Unfortunately this does not solve the problem, since the hiss is still there when I play back the recording -- somehow it's just absent from the monitoring sound, when Line-In is muted.

Curiouser and curiouser.