At the output of an LM741 opAmp I have 16Vpp sine wave @ no load. I want to use this sine wave on an 8 ohms load with 1.5W power . Therefore I need 3.5 Vrms and 0.43 Arms on the load. Now, if I directly connect the load to the output of the opAmp, the voltage on the load drops to 0 immediately, and I assume this results from the fact that max current output of opAmp is around 20mA so it is not enough obviously.
Also I want to be able to adjust the power on the speaker, i.e the amplitude of the incoming sine wave.
So, what is the best method to drive that load with adjustable levels of output voltage? I would appreciate if anyone supplies an answer not involving buy this regulator or buy this converter etc. (***)Rather I prefer things like building a transistor amplifier circuit etc. Anyway, I am also open to other advices.
*** : actually, I have to design all these steps for a project. That's why I ask the fundamental methods. I know how silly it seems not using a commercial IC. By the way, the output of the 741 is the direct source of the sine wave. It is a sine wave generator(wien bridge oscillator) actually. I wonder can I do the amplification part seperately from that 741 oscillator circuit.
p.s : don't think matters but the load is a speaker which will be driven at 1kHz.