On Sat, 5 Jun 2004 11:30:52 +0100, "Keith G"
wrote:

Ok, I'll buy that - presumably the 'autogain control circuit' is in the mic,
Mike? (New component, new phenomenon....) But why/how is the waveform pulled
down from the 'centreline' or is that just a 'software thing'?

The big pulse puts quite a hefty charge onto the input coupling
capacitor. The movement negative and subsequent recovery are simply
that charge leaking away again.

d
Pearce Consulting
http://www.pearce.uk.com