Hi there fellow Instructablers!

I made this mini stereo amplifier for my son, it is powered by a used laptop 19V 3.43A adapter-charger. the audio source is his laptop headphone output. This amplifier will drive two bookshelf speakers. The heart of this circuit are two TDA2003 audio amplifier costing around $ 1.5 for a pair here in the Philippines. Overall cost is around $10.00 not including the laptop ac adapter and book shelf speakers. The input from the audio source is wired to a dual gang 10K volume control. Pin 1 of the volume control (variable Potetionmeter) is wired to ground, Pin 2 is wired to the input of the amplifier, and Pin 3 is wire to the rca jack. total output power is 20 watts.

Step 1: Circuit Schematic Diagram

here is the tda 2003 schematic diagram make two of this circuit for stereo or dual channel!

parts list :

2 pcs. TDA2003 integrated circuit amplifier
1 pc. 10 k Ohm stereo volume control
1 pc. plastic knob for the volume control
1 pc. perforated pcb
1 pc. suitable plastic casing
1 pc. aluminum heat sink fins
1 pc. dual rca jack
1 pc. mini stereo jack
1 pc. dual speaker terminals
1 pc. crown dc jack (adapter input)
1 meter soldering lead 0.8 mm 60/40
4 pcs. 1/4 plastic stand or double mounting tape
2 pcs. 39 nf ceramic capacitors
4 pcs. 100 nf ceramic capacitors
2 pcs. 10uf 25v electrolytic capacitors
2 pcs. 100uf 25V electrolytic capacitors
2 pcs. 470uf 25V electrolytic capacitors
2 pcs. 1000uf 25V electrolytic capacitors
2 pcs. 39 ohms 1/2 watt resistors
2 pcs. 2.2 ohms 1/2 watt resistors
2 pcs. 220 ohms 1/2 watt resistors
2 pcs. 1 ohm 1/2 watt resistors

Step 2: Tools Needed or Required!

tools

soldering iron
long nose pliers
side cutter pliers
electric drill and drill bits
screw driver set

Step 3: Assemble the Circuit Board!

using the perfboard or proto board, mount all the components as in the pictures, and solder junction and connectors under and over the perfboard or proto board.

Step 4: Make the Casing!

with your suitable plastic casing, drill out for mounting the hardware. use masking tape for the pencil marks.

Step 5: Install the Circuit Board Inside the Casing!

After drilling holes for the hardware, install the circuit board and assemble everything in place!

Step 6: Your Finished Book Shelf Stereo Amplifier

Here some photos of different views of the amplifier!

Step 7: Amplifier in Use, With My Ipod and Radio Shack Book Speakers

Here, i am testing the amplifier using my ipod and two radio shack book shelf speakers. my power supply came from my old laptop. It is a 220Volts AC to 19Volts DC 4Amperes brick adapter.