Presented here is a amplifier based upon the LM386 Audio Amplifier.
There is a standard circuit in the data sheet that is an excellent place to start.
Materials needed (digikey part numbers):
1 - HM359 project box
1 - 668-1237 speaker
1 - LM386N-4 amplifier
1 - BS6I battery conn
1 - CP1-3515 stereo jack
1 - SC1316 stereo jack
2 - 450-1742 knob
1 - 679-1856 switch
1- 3mm LED
1 - 10 ohm 1/4W resistor
1 - 10uF ceramic cap
1 - .05 uF ceramic cap
1 - 420 uF electrolytic cap
1 - 8 ohm resistor
2 - 51AADB24 10K pot
1 - HM1252 circuit board
wire and solder
Step 1: Prep the enclosure
Begin by laying out the components on the circuit board that will need to pass through the enclosure. This enclosure has a removable top panel which will be used for the volume, gain and 1/4 inch stereo jack.
Space is limited to check for fit before drilling.
All drilling of the plastic should be done with a step drill bit. This will make the cleanest holes without breaking the plastic.
Lay out the pots a few spaces back but still in line with the desired position. mark the center of each pot shaft then drill with a step drill tot he tightest fitting hole size. Make a center mark between the pot holes then drill for the stereo jack
On the inside of the top cover position and mark where the speaker will go.
Make a template on grid paper the same size as the speaker.
Tape the template to the inside of the cover as shown then use a step bit to drill holes on the center of every square in the grid. This will form the speaker grille. clean up the holes.