Microphone and Pre-amplifier question

Good day!

I'm looking at the following products:

Electret Condenser Microphone
http://www.knowlesacoustics.com/images/specs/MB6022APC-1-A-2004-06-01.pdf

MAX 4469 Mic-Preamp
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2469

I was hoping you can help me answer some questions that I have.

On the MB6022APC data***, they show a 33pF & 10pF capacitors in
parallel. What is the meaning of this? Why is it not just a single
43pF capacitor?

I also checked Knowles Acoustic design guide, and they mentioned that
their microphones are either 33pF, 10pF, or 33&10 pF. I don't know
what this means.

Also for the MB6022APC mic, the data*** shows a sensitivity of -42dB
(min) at 1kHz with 1PA pressure (0dB = 1V/Pa). Does this translate to
a voltage output of .007943V at 1kHz with 1PA pressure for this
microphone?

If that's the case, my calculations show the following:

At 20dB SPL, microphone voltage out is 1.5886 microvolts. At 50 dB
SPL, microphone voltage out is 50 microvolts.

Maximum workable gain for MAX4469 is 30V/V with a bandwidth of 20kHz.

Using these values, the output of the MAX4469 pre-amp at 50dB SPL is
1.5mV and 47 microvolt at 20dB SPL.


If I got these numbers correctly, then are 1.5mV and 47 microvolt
usually workable levels in terms of audio? Would I need another
amplifier stage following the MAX4469 pre-amplifier to boost the
voltage levels even higher?

Thanks!

.

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