15W 8 ohm simple amp

[palesha]

I want to make compact multimedia stereo amplifier. I also want to put subwoofer amp in same small box hence heat will a problem. I wish to use the fairchild opamp amplifier circuit for satellite speakers. I think it will generate less heat & very easy & compact to make. I am doubtful about 10 ohm resistor value in the circuit. I need comments and suggestions about the circuit behaviour.
Mahendra Palesha

 

[e96mlo]

This is a similar circuit but with current feedback. Could give you some ideas perhaps.

/Marcus

 

[Tube_Dude]

Hei e96mlo!

Your circuit is not so identical...it is very diferent in the propouse.
In the Palesha circuit you have a voltage amplifier...in your circuit you have a transconductance amplifier(one that outupt a current proporcional to voltage imput).
that put us the old question:is a loudspeaker a current or voltage drived device?
So the 2 circuits will have a very diferent sound because the output inpedance of the Palesha circuit will be near zero and it have a high damping factor...the e96mlo circuit will have a near infinite output impedance(it behaves as a current source)so the damping factor will be near zero.

Regards

Jorge

 

[PMA]

Palesha's schematic is not so very often used circuit that works as follows: an op. amp. modulates +Is, -Is supply current according to a signal level. Those supply current changes are monitored by output transistors connected in common emitter way. The feedback resistors estimate a voltage gain. I would prefer "standard" circuit with OA and 2 transistors increasing OA output current.

 

[palesha]

Dear PMA,
Can u suggest some circuit for my requirement?
MP