[help!]

sir is this really a working circuit?

if i do the circuit you've shown can i use TL071CP for the op-amp?
and can i use an 8-ohm 1w speaker for the output?
for the potentiometer, can i use an ordinary potentiometer?
and i posted a picture of the electret mic. does electret mic has polarity?
c2,c3,c4 are electrolytic right? what is their voltage rating?
and for the resistors are they 1/4W?

sorry for the many questions sir.

[help!]

which one is more reliable amplifier?

can this will work?
because i don't know how to simulate it and i want to be sure that it is working before i buy the components..

or give me another simple circuit about mic pre amplifier.
thanks!