Thank you for the quick reply guys!
So obviously I need some kind of amplifier, and the higher the power of the amp, the louder it can get. THing is that if I want to build something simple, the idea of a high power amp seems unattractive. I have access to different kinds of OpAmps, and I could also borrow a (+- 19V, +- 15V, +- 9V, +-5V) power supply for this hypothetical circuit.
I'm not really concerned about the loudspeaker sound level, nor the quality. I just want to give it a try since I have all these components available. So do you think that using a "high power" OpAmp-based amplifier, with a supply of +19 V maximum, I could get a reasonable sound level out of it? If so, is that LM386 a good option? do you have some other candidates?
Thanks guys! I appreciate a lot the feedback