Step 1: What you need
Ferric chloride or similar
Some box to put the circuit in
bakelita or similar
electrolitic 220uf cap x2
electrolitic 10uf cap x2
ceramic 10nf cap x2
ceramic 100nf cap x2
100ohm resistor x2
1.5Kohm resistor x2
22ohm resistor x2
jacks or plugs for the speakers (if wanted)
3.5mm stereo plug x1
Step 2: Schematic and circuit design
Step 3: Print or draw
-If you are drawing it, use the permanent marker, if you are using the eagle board file remember to mirror it befor drawing.
-If you are printing it you need to do it in couche paper, then put the paer with the circuit facing the copper side of the board, then use an iron to heat it, slowly n carefully, do it just one minute. then wash careflly the board to remove the paper.
Then put in a plastic bowl one part of water an two of Ferric chloride and put the board with the copper side facing up and shake gently the bowl.
When the rest of the copper is gone wash the board. Finally drill it. Carefully.
Step 5: Conect speakers
Step 6: Find a box
Now connect the usb cable to your laptop and your mp3 player and enjoy.
I will be glad to answer any question.