QA471 mic pre question

Hi Matt, can you share the input Z of the 2 independent gain blocks? I can’t seem to find that spec. Thanks!

Hi @Chicago, the input from the BNC is as follows: Shunt 100K, series 22uF/100V, shunt 100K, series 49.9 ohm, into OP1612.

So, roughly, your looking at 50K input impedance.