I've made a couple of these. I found the original schematic online then modified it because I did not have one of the parts the original plan calls for. My design allows the use of much more common parts. Although it uses more parts and is a bit more complicated.
Step 1: The Schematic
Looking at a schematic is always how I decide of I want to build a circuit or not so I will present it first. I found the one I based my design off of here:
Although mine isn't exactly like that one it is essentially the same topography. It sure looks simple enough doesn't it? That is why I choose to build it myself. I made my schematic because I did not have a TLE2141C Op-Amp. If you do then you can build the original and it should be easier than building mine.
IC1 and IC2 on my schematic are 15 volt regulators I used 12 volt ones. SL4 from the power supply section should power the lower voltage dual op-amp of course.
Step 2: Board
I've made so many of these I'm not really so sure which is what anymore. I know I cleaned the schematic up a little before I uploaded a screen capture of it for the previous step. I'll be honest, often when I am doing an electronics project I just want something to work so I don't spend as much time as I should making my schematics as neat as I could before I move on to the next step.
Just so long as everything is hooked up you know? Sometimes I find while I am routing a board that some things aren't connected to each other too! Then I have to go back and fix that.
Anyhow the one I am including here looks pretty good to me. If anyone finds any problems then let me know and I'll see what I can't do to fix it.
Step 3: Power Supply
First I'll cover the input stage of the power supply for this project. It is a center tapped, rectified, then filtered configuration. Exactly like what is described here. Now I'll get some mileage out of that Instructable. No one ever bothered with it as of now.
You can see in my picture that I have 40 volts between my VCC and VEE, which gives me +-20V. Close enough for the 22V the circuit calls for.
Step 4: Choose Your Poison
I've made this amp on perfboard, and etched boards for it too. Either way works. I'll offer some build pictures in this step.
Step 5: Closing Thoughts
This is a pretty loud and sweet sounding amp to me. With my circuit one of the op amp sections of the dual op-amp is used as sort of a preamp stage and the trimmer next to it is a gain control. I like mine loud. The other trimmer by the transistors is the bias setting, jack it up until amp misbehaves, then back it off some. You're good to go!
I've had a Fender tube amp, I have a Marshall Lead 12, and I've a couple of these amps I've built. I like my amps the best out of the bunch. You could easily find someone willing to soak you $100 or even more for an amplifier like this. So why not build one out of some junk and rock instead?
Oh for the output transistors any matched audio transistors seem to work to me. If the pin outs of your transistors are different either bend the legs around or change them in the schematic and reroute. If the whole project blows up, well that is even more rocking! One of mine already has.
This ain't no cheese whiz LM386 amplifier. This puppy pumps.