blocking cap value question

I don't fully understand your post. Are you floating the + input of the opamp at half the supply voltage with a voltage divider of two 22k resistors? If so, the load on the capacitor is 11k ohms. Generally, one uses a capacitive reactance of one-tenth the load (so you want Xc = 1 k, or less, at the lowest frequency of operation).

I am confused about the 10 M resistor.

If the OP can access a.b.s.e. perhaps [s]he can afford us a schematic; barring that, an ascii schematic would work.

That way we'd have something more solid to work with.

Cheers

PeteS

Your post is a bit confusing, what low frequency response do you need, and what are you ampilifing? Blocking caps will define the -3dB points, if you have a high impedance input, say 10M, then the cap can be quite low, but without knowing the lowest frequency, it is impossible to calculate

martin

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Good plan Pete. I now realize that my origianl post is a bit confusing. Check it out on ABSE.

Thanks

use something in the neighborhood of 0.1 * 22k = Xr. etc... for that application, it's close enough.

"tempus fugit"

Use a 0.22 uF film cap.

........ Phil