How to amplify your acoustic guitar for under $10
If you have a musical birthday card or whatever at home, remove the audio unit its the 1" or so round disc usually white with a small brass ring around the edge, handle carefully as they are not to strong., keep the wires on it by snipping at the opposite end, it will make things easier later, If you don't have one, buy a $1 musical card of any discription and proceed as above.
Next wherever you are comfortable with it, drill a 1/4" hole to accommodate a 1/4 Mono jack socket
Next solder two wires to the jack socket one to live tag and one to shield use two different colour wires and id the earth one, say if its black make a note of that(earth tag) make them about 6" long, fit socket into hole by putting your hand with socket into the sound hole and into the hole made to take the jack socket, screw the nut on socket end to make firm bring the wires out of the sound hole, fix the earth wire to the wire that goes to the outer ring on the disc (Solder (Best) or twist and tape connect the other wire to the remaining wire from jack socket.put some blue tak on the outside of the disc the opposite side to where the wires are attached put your hand in the sound hole and press the disc to the underbody a position about central under the bridge, you can experiment for best position for you.
PS attach the disc with the small hole in center and white plastic area facing upwards under bridge, or wherever you like it best.....Plug into your amp adjust according to your liking and away you go.
As above except dont drill a hole rather place the jack socket via blue tak or velcro to the top of the guitar by the edge towards the rear of guitar, where the wires exit the sound hole blue tak them the the underbody to keep neat and out of the way.