Steve Smith writes:
>Use a simple duel op-amp to give some gain to the mic and then drive a the
>second op-amp as a presicion rectifier to charge a cap on an analouge input

        What kind of amplifier configuration is a precision rectifier?
I may already have a good idea, but I figure some of you are experts and can
set me straight.  The circuit that comes to mind is an op amp set for some
particular gain in the usual way with the trick being that the AC signal
is fed to a pair of diodes such that positive half-cycles go to one input
and negative half-cycles go to the inverting input.  Is that all there is?

Martin McCormick