Construction of a 2*25W solid-state dual-mono amplifier
Text and images copyright (c) 2003 Jan-Erik Skata. PCB design visible by original author.The amplifier is based on this design: DIY 25 W Class-AB Power Amplifier.
As said in the page, 25W may not "look" very much, but it is sufficient to drive a small two-way speaker with 5" midbass.
The sound is actually quite good, much more detailed than a 2*60W amp I built before.
PCB construction
A standard desktop flourescent lamp was used for exposure, about 45 mins
with a fresh PCB.
Board masks, for power supply.
Developing the exposed board in NaOH solution.
Developed (and slightly corrected) amplifier board.
Soldering components
Amplifier board, mostly resistors soldered.
Electrolytic capacitors, small-signal transistors and trimmers added.
Most components of the amplifier board in place.
(I would not be ashamed to show the solder side, I just don't have any pictures of it).
One power supply completed.