Hello,
This is my first post on this forum, I'm new to electronics but eager to learn
I have a big interest in audio and I want to make an amplifier for a 8ohm 0.5W speaker I have lying around, if I connect it directly to the audio jack of my phone
it barely makes any sound. So after some research I discovered I need an amplifier IC. So after hours of digging around on old pcb's I found a chip. An LF 351N. The datasheet gives says it's an op amp, but for circuitry I could only find some exemplary uses on the datasheet. I found a circuit for an inverted amp, will an inverted amp be suitable for listening to music? Anyway, I'm looking for a cicruit for this chip to make an amplifier. All help is appreciated.

 

You wont make a loud noise from that chip, you're better using a Lm380...

 

It is correct to say that you need an amplifier but all amplifiers are not created equal. What you need is a power amplifier.

An op-amp (operational amplifier) is the generic term for an idealized type of amplifier.
An ideal amplifier has some desired characteristics:

• Infinite input impedance
• Zero output impedance
• Infinite voltage gain
• Infinite band-width

No such op-amp exists.

What you are looking for is a power amplifier designed to drive an 8-ohm speaker with a certain amount of power (0.5W as you requested) with a frequency range in the audio range 20-20kHz.

LM380 is one example of a low power audio amplifier.