Here you go. Hand drawn on the back of an old envelope.
Component values should not be critical but try to keep close to those values. The 10uF capacitor should give you a low frequency rolloff of around 15Hz with most low impedance mic preamps. If you don't get enough level, try experimenting with the value of R1 but I wouldn't go below 1K ohm or above 22K ohm.
R2 and C1 prevent DC appearing across the mic preamp input.
You may need a fair amount of gain to get a good level. That all depends on the output of the mic capsule.
This is an UNBALANCED circuit. Keep the cables as short as possible.
The XLR view is from the solder terminal view, not the pin view.
If you are using Apple earphones and just using the mic and not the earphones, leave the tip and ring 1 disconnected. You will possibly run into crosstalk issues (earphone signal leaking into mic preamp) if you try to use the earphones and the mic at the same time.
There's no harm in trying though. It may work well.
Do not use phantom power with this circuit!
Click image for high resolution
