DIY amplifier for 500 rubles


Created on 04.02.2010 20:55.

Updated 02.02.2020 19:16.

Author: cramen.

It was a long time ago, I decided to write now only. S-30B columns were available. I wanted to make home acoustics for my computer. There was not enough amplifier. I went shopping. The lower price of amplifiers / receivers of low power (30 watt speakers at the peak) is about 6,000 rubles. I decided to do it myself. Let’s start

Tube – for audiophiles, and there are many problems. Transistor – it takes a long time to set up, and the element base must be selected precisely, because the errors in parts sold in the markets and in stores sometimes reach 10%. As a result, the choice fell on microcircuits.

Googling and reading the forums, I chose the TDA2050 chip. Connection diagram:

As you can see, the body kit is minimal. They also need radiators. I took 500 rubles. and moved towards radio markets and shops. The entire element base cost a little more than 100 rubles. The source of the scripture was also needed. I will not delve into the details of nutrition. Diode bridge + output capacitors – about 100 rubles more.

I bought radiators on the market from the old first stump 2 pieces for 20 rubles. + I bought more little things, which will be discussed below. Returned home. We need to make seals. I decided not to bother for a long time. I took a piece of PCB out of the bins, marked the tracks, drew them by hand with a marker, which is in the photo below.

I etched it with ferric chloride (again I got it from old stocks). I decided not to drill the signet, but to solder the parts on top of the tracks.

The power supply is a little more responsible. Then I drilled the textolite, because the condensers are large and if you solder them from above, you get a large mechanical load on the copper foil, it can peel off. Well, + stabilizers for + -12 volts, just in case, for the future I attached on ordinary zener diodes + a transistor with a resistor;)

A little later about the transformer. All connected by a canopy. I connected a sound source and speakers. Poper self-excitation. Beeps and that’s it. Soldered directly to the feet of the food mikruh film Conder 100nan. The excitement is gone. Chased for an hour – it works.

Now the body. The old Vega 10U-120S was lying around (from which there was a transformer)

Threw everything out of him except the trance. I cleaned off the silver, put a plate on the front panel. I painted everything (the usual paint from the spray can remained matte). Here’s what happened. (I did it about 2 years ago, so it’s already shabby)

The power supply plugged into the place of the 2 condenders that were there

Volume control – a regular 2 kilo-ohm variable

The reinforcements were screwed on by 1 bolt. They are lightweight so they hold securely.

I bought the knob of the regulator (variable) of the amplifier for 10 rubles sometime ago

Wires for the audio signal: I bought 2 meters of microphone cable for 30 rubles a meter. Everything began to look like this:

On the back wall is the socket for the input signal and the output terminals. I connected a computer and speakers. Everything worked right away and without any complaints.

I’m not a big fan of sound. In my ear, it plays no worse than what is sold in the store at a price of 6-10 thousand rubles. But it is definitely better than it was when there were native guts in this amplifier case. The high-rises appeared normal, the bass was more or less cut through. Probably it was bad because of the dried out old capacitors in the old giblets.

In general, after all this was ready, from 500 rubles remained 30 rubles. All this taking into account the travels from shops to shops. After a while I took a Magnat Monitor Sub 200 A subwoofer (then it cost me 5000 rubles). But this is already a conversation about acoustics and another topic.

Since then, I have never complained about the sound. Everything works flawlessly. Enough for background music and for movies and for parties, so that the neighbors will listen.

ps This story was long ago, so some in moments could lie a little.

Source: HabraHabr.RU or