In this video, I show how I go about designing a transistor small signal audio amplifier, I explain in detail the methods I use to design each stage using my signal generator and oscilloscope, as well as the details using basic ohms law to calculate the biasing resistors.
I show in this video how I configured the output stage to use a 8 ohm speaker for the output without needing to use any kind of transformer coupling.
I use a 8 ohm speaker for the input as well, as to use as a makeshift microphone, for audio signal pickup.
At the end of the video I demonstrate the sensitivity of this circuit, to pick up very small audio signals, first demonstration of how it picks up me whispering into the input speaker, and the clarity of the sound, then I demonstrate how it can pick up the audio sounds of my android ipad, by placing the ipad ontop of the input speaker and turning it on, to listen to the internal sounds it makes when booting up, and then shutting down.
My disclaimer is this, I am a hobbyist in this hobby, so all the circuit design I do in these videos, is only at a hobby level only.
I make no claim to be designing these circuits as done in the profesional field, just having fun designing and making things.