Well that was a fun morning and a good way to avoid shoveling heavy corn snow from the driveway.
I downloaded the TI Analog Simulation Program (I'm not an analog designer), modified the transfer characteristics of the electret mic preamp to try to cutoff about 4KHz to sample at 8Ksps, and ordered the parts from Digikey!
This (below) is about as good as I can do with a single-pole filter I think.
And thanks again.
Bob
wm6h
