This small, all through-hole component kit is a reissue of an older KitsAndParts.com kit.
This is a new board layout and all new components, including Fairchild transistors.
It can be powered from as low as 3 volts (with reduced power out) up to 18 volts DC.
With a voltage gain of around 40db (65db power gain into 8 ohms), its performance is similar to the LM386,
but with lower noise and hiss.
Maximum output at 8 ohms is about 1/2 Watt using +12V power.
This is a very easy kit to assemble. Follow the schematic, then load and solder in the parts.
The resistors are mounted vertically. Obey the polarity markings for the electrolytic caps.
With no load or source attached, apply power.
Adjust R8 for half the supply voltage measured at R6:R7 and ground. This sets the bias.
Now connect a source and a speaker.
Remember that this is a fairly high gain circuit. Mind your input wire lenghts and routing.
I can listen to my local AM station by just touching the input pin with my finger :-)
1 mV (Hi-Z) input produces 50 mV output at 8 ohms.
Distortion starts at about 1 volt RMS output into 8 ohms.
Board size is 30mm x 40mm with mounting holes that will fit 4-40 screws