Today it is no longer considered fashionable to solder various shiny parts on a homemade circuit board, as it was twenty years ago. However, in our cities there are still amateur radio clubs, specialized magazines are published in offline and online modes.
Why did interest in radio electronics plummet? The fact is that in modern stores everything that is required is realized, and there is no longer any need to study something or look for ways to purchase it.
But not everything is as simple as we would like. There are excellent speakers with active amplifiers and subwoofers, wonderful imported stereo systems and multi-channel mixers with a wide range of capabilities, but there are no low-power low-frequency amplifiers at all. As a rule, they are used to connect instruments at home, so as not to destroy the psyche of neighbors. Buying a device as part of a powerful device is quite expensive, the rational solution would be the following: tighten up a little and create a home-made amplifier without outside help. Fortunately, today it is possible, and uncle-Internet will be happy to help with this.
Amplifier, "assembled on the knee"
The attitude towards self-assembled devices today is somewhat negative, and the expression "assemble on the knee" is overly negative. But let's not listen to envious people, but immediately turn to the first stage.
Initially, you need to choose a scheme. A homemade ULF-type sound amplifier can be made on transistors or a microcircuit. The first option is highly discouraged for novice radio amateurs, since semiconductor devices will clutter up the board, and the repair of the device will become more complicated. It is best to replace a dozen transistors with one monolithic microcircuit. Such a homemade amplifier will please the eye, it will turn out to be compact, and it will take a little time to assemble it.
To date, the most popular and reliable chip type is TDA2005. It is already in itself a two-channel ULF, it is enough just to organize power supply and apply input and output signals. Such a simple homemade amplifier will cost no more than a hundred rubles, along with other parts and wires.
The output power of the TDA2005 ranges from 2 to 6 watts. This is enough for listening to music at home. The list of parts used, their parameters and, in fact, the circuit itself is shown below.
When the device is assembled, tomicrochip is recommended to screw a small aluminum screen. Thus, when heated, heat will be better dissipated. This homemade amplifier is powered by 12 volts. To implement it, a small power supply or an electrical adapter is purchased with the ability to switch the output voltage values. Device current is 2 amps or less.
You can connect speakers up to 100 watts to this ULF amplifier. The amplifier can be input from a mobile phone, DVD player or computer. At the output, the signal is taken through a standard headphone jack.
Thus, we figured out how to assemble an amplifier in a short time for little money. Rational decision of practical people!
