Transistor Amp

[Warlord_1011]

Now then, I have a Ipod (2nd Generation) and i wish to make a amplifier, however i have no real idea where to start, ive been looking around and i found these specs on the audio jack of the Ipod NANO

ipod nano 30 mwatt , 32 ohm , 0.965 volt , 0.03 amps

Now for one i dont know if these are correct but i dug around in my garage and came across some old transistors, and some other bits, i tried a few circuits my dad sugested (tho i dont have any offical schematics they were on bits of paper) but none of them worked, i used a BC 108 transistor, and it always made audio quieter, and i have no idea why???

also:
1)How do you determine how much the transitor will amplfiy by?
2)How do you calculate what resistors to use to bias the transistor?
3)How many transistors would i need to amplify the Ipod to drive this Drive unit:

Impedance 8Ω
Power rating 10W
Frequency response 120Hz - 16kHz
Resonant frequency 120Hz
Sensitivity 1W, 1m 88dB

4)Could you use a Op Amp 741 to amplify the Ipod (if so what inputs etc)?
5)What is Reactance and RMS?

i know there may be quite a few questions there what arent all easy to explain, but any help would be much appreciated and i will give a Cookie to anyone who can answer all!

 

[MikeMl]

What impedance/power level are you trying to drive???

Why don't you just feed the IPod into your home stereo or car's stereo instead of trying to duplicate the expensive speakers, etc?

 

[Warlord_1011]

1) as i stated its a 78mm 10w 8ohm drive unit
2) i need it portable so i can have it in the workshop and can easily be moved when needed (i need it to run off of no more than 12V)

 

[EN0]

A single transistor won't give you 10W, that much is certain. There are simple ICs that will give you nice linearity and efficiency in a small package. Search Texas Instruments, Analog Devices, and other semiconductor companies to find the IC you want. Also, you can power them from 12V, like you want.

Austin

 

[Warlord_1011]

nah i meant how many would i need etc, or any example ic's, or infact could i use a 0p Amp 741