A simple amplifier on the chip TDA1557Q (TDA1558)
The ULF is designed for 2 Ohm loads, but works fine on the 4 Ohm assurance with 40 watts per channel. On 4 Ohm speakers power will be about 25 watts. To get 40 watts, you need to connect to the amplifier by two pairs of 4 Ohm speaker = 2 Ohm. In the car a lot of speakers, so the total capacity will be about 80 watts. It feeds the amplifier circuit 16 volts maximum current consumption at rest = 110 - 180 mA. All soldered correctly works. Never confuse a plus and a minus, otherwise the chip will burn immediately. Install it on the radiator, it should be the more - the better. Here is soldered scheme:
There is also a printed circuit Board. [attachment=3] I did not work out very well, but the amp is really working. The photo of the PCB:
Bought 2 chips, one half to his friends. The body was taken from the old speakers, the speaker outputs from the rear panel.
Works unch through a transformer 12 V. Now worth about computer - very pleased with the work. Even better would be to login to add your e-tonestack.