I am trying to build a very simple amplifier type device to power a 4ohm 150 watt piezo tweeter. I am getting my signal from an mp3 player and then want to use a voltage source, 9-20 volts, to amplify the signal to as much as possible and as simply as possible. The goal is 120db. I have talked to a few people and all give me different ways of doing it. The simplest way I was told is using a basic transistor amp circuit and it would work.
Can I use this very simple circuit and just replace the small transistor with a larger mosfet and apply my 9-20 volts? Will anything back feed into my mp3 player and destroy the output?
I don't really care about quality sound since it will just be constant tones coming out. I just need them to be amplified as much as possible and very simple.