开云体育

Thanks Tim.
I think I’ll try to build that circuit with the OPA172.

Bob
wm6h

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

I've no idea what you are trying to do with this filter,
but it won't be suitable for voice or many digital modes.?
The 2khz response is down more than 10dB from the 100hz response.