First you need to learn how discrete circuits work and how to measure / troubleshoot
them.
I agree. As you point out elsewhere, things have moved from learning
these details to using functional blocks created by others who know.
That's too bad in some ways. In others, it means more people can have
at it without having to spend so much time informing themselves well
and fully, I suppose.
I'm just a hobbyist and in no way do I imagine I understand all of the
important details. But I've cobbled together my own designs for a few
usably working audio amplifier circuits, when I was much younger. And
at least for me, learning things in discrete steps helped a lot. At
some point, it's time to figure out how to combine functions a bit.
But to start out, separating them seems to help. For me, it did.
Part of this will be learning about conditioning the input source
appropriately and well. Degenerative voltage amplifiers aren't that
hard to understand and design and may be a good place to actually
start. In that regard, the student manual for the Art of Electronics
is important -- the book doesn't cover the details well enough on its
own -- if that book is to be used. The student manual includes a
"compute this first, then that second, then..." approach. Very easy
to follow. (Then include bootstrapping of the input from the BJT
emitter as a 'next thing' to gather well.) As you also point out in
another post, emitter followers for output.
Although some of these functions can be combined in a given design, I
don't think I could have handled it when I was going through this. It
was the fact that they could be taken in steps that allowed me to
succeed, as much as I did. So I recommend taking this in parts.
I started out trying my hand at understanding the basic degenerative
BJT amplifier, then gaining a foothold on the bootstrap to stiffen the
input a bit. I used a well designed power supply, a well designed
signal generator, and a well designed oscilloscope as tools --
designed by professionals while learning about simply voltage
amplification. (It's remarkable to me how complicated it all seemed
at first and how so much simpler it seems in after-thought, looking in
hindsight.) It was after that when I began worrying about how to work
with various input sources worked; sometimes their own supplies and in
all cases some kind of matching to avoid distortion or avoidable loss
of signal. I actually built my own carbon granule microphone, in
fact. Most of my experience was with dynamic microphones, but later
this included electret. Then I worked on outputs (mostly just the
typical 4-8 ohm speaker, but also various kinds of headphones.) One
such I also built by hand, winding wire, using fixed magnets, and
using tiny metal plates as diaphrams.)
It was fun but took a lot of time. I made stuff that didn't work
well, too.
You'll have fun finding a book that'll teach that. My first came from 1969 (
Mullard ) followed by an RCA handbook and a full blown theory book my Dad
bought me and people were already well into ICs by the mid 70s.
I learned this stuff in the late '60s and early 70's, when I had the
time as a kid and young adult, too.
Jon
