| After running SPICE simulations of this circuit, my opinion is that a 1uF is fine for that part. 25 or 35 volt Tant will be ok - which is probably what is in it stock.
Provided the stock microphone has a quiet FET in it (if not you could do a 2sk170 or similar) the biggest improvements come from (1) changing the coupling cap between capsule and FET - I like using silver mica for these and (2) changing the output coupling caps to something better. |