Audio Amplifier ?

[zika1212]

help me in designing a 10 W audio amplifier using discrete components (transistors , diodes ,... ) ,, i need schematic diagram and parts no. for mic ,speaker ,... ,,,,,,,

 

[Dr.EM]

Heres some links that might help you:

https://circuitos.tripod.cl/schem/r77.gif

And a site with loads of schematics:

https://www.commlinx.com.au/schematics.htm

 

[TheOne]

AC coupled amps (low frequency response not as good as DC coupled) are much more safe as far as damaging speakers in case of a faulty output stage, especially if you design/build the amp yourself. DC coupled amps can burn the voice coil of a speaker when one of the push-pull arms go short circuit without protection circuitry to disconnect the speakers from the amp. Oscillation in amplifier designs is a big problem in general because of the high gain, feedback and type of load being driven. The in-experienced constructor/designer may easily end up with a circuit that starts to oscillate at the higher frequencies due to layout or compensation problems resulting in spectacular destruction of the output transistors and the speaker in case of a DC coupled amp. Amps have a real problem driving capacitive loads and may burst into oscillation if there's enough phase shift with feedback and gain. This oscillation heats up the output devices very fast in seconds. Remember the old saying "The best way to design an oscillator, is to try and design an amplifier"? :lol:

One popular test is to feed a square wave into an amp and watch if there's any tendency to oscillate on the output waveform driving the speaker load. This will also give you some idea how well the amp handle low and high frequencies and how flat the response is.

 

[audioguru]

Hi TheOne,
Mika wants to build an amp for a mic and speaker. With the mic in front of the speaker, you can be certain it will oscillate!

 

[TheOne]

"Hooowwl!"