ivanp, there is a reason I deliberately support specific microphones...
If you just try to plug in a typical mic, you will have echo cancellation problems.
Period.
The USB microphones I am adding support for have a phase cancellation loop where the microphone is closely coupled to its own sound card, where a speaker is connected, so that anything being spoken can be phase cancelled...
So, go ahead, bang your head against the wall, or listen to me.
-Thom