In order to have an amplifier for sound at home or in a car, it is not necessary to buy it in a store. Making it is not difficult at all. To do this, you need to have a little knowledge of electrical engineering and a little imagination.
It is necessary
aluminum sheet, square, strip, TDA 7294 microcircuit
Instructions
Step 1
Take a 15x15 mm aluminum square, you will need it to make the case. Cut the blanks. Make upright racks. The total thickness of the amplifier will be 60 mm, the glass cover will be 4 mm thick, the bottom will be 1.5 mm, and the rack height should be 51.5 mm.
Step 2
Make horizontal frame elements. To make the docking comfortable, cut each end of the square at an angle of 45 degrees. To assemble a case with dimensions 430X250X60, you will need eight squares - 4 pieces 422 mm long, and 4 pieces 250 mm long.
Step 3
Assemble the frame. This should be done using the M3 screws, which will be very convenient in this case. Collect two squares on one upright post. Next, make the bottom and back wall. For this, use a 1.5 mm thick aluminum sheet. Cut with a jigsaw. When you cut, make it a millimeter larger to fit the overhanging edge more easily. Attach the finished bottom to the frame with screws.
Step 4
Make the back of the case in the same way. On the back of the case, install the power connector, input and output sockets, which are best purchased in advance. Then drill holes in the back wall. Make the legs for the amplifier, you can take them ready-made from an old suitcase.
Step 5
Make the front panel. To do this, use a 5 mm thick aluminum strip. For the case, you need to make a bar that will hide the mechanism. If desired, the body can be painted with spray paint.
Step 6
Make a switching board in the following way: print the image of the future board on a laser printer at a 1: 1 scale. Then the drawing should be cut and placed with the image down on a previously degreased piece of fiberglass. Then transfer it to the foil, ironing it with a hot iron. Its temperature should be at its maximum. Iron thoroughly for 2-3 minutes and let the board cool. The toner will melt and adhere to the foil, then remove the paper in warm water. The result is a very professional quality printed circuit board.
Step 7
Make a board for the capacitors by drawing with a drawing pen. To do this, use an ordinary syringe with a blunt needle. Pour nitro varnish into its body and draw paths with it. Etch both boards in ferric chloride solution and collect.
Step 8
Isolate the TDA7294 microcircuit from the radiator, so it has a negative potential on its case. This can be done using a special heat-conducting pad, which should be slightly larger than the sole of the microcircuit or mica. Insulate the screw mount with a non-conductive sleeve. Insert the boards into the case.
Step 9
Bring the amplifier control knobs to the front panel. Secure the top cover.
