As I did the budget amplifier on the TDA2050 for old speakers
Under the cut photo, a description of the process, some diagrams and a detailed description of some moments of the creation of this miracle.
Here come the old Soviet speakers S-50 (if my hands reach, I want to upgrade them, but so far there is, that is), their TX:
And with them I got a great amplifier Odyssey U-010, which burned down. Having examined it, I realized that I would not do anything with my scanty experience. Touched Google a little, looked at the profile sites and here it is a solution - we will make ourselves an amplifier based on the TDA2050 chip as a replacement for the old one. For " Handmade and DIY forever, " and not so difficult. TX TDA2050:
')
(Immediately, I might have come across a fake, but with a short circuit, one TDA2050 exploded so that a chip fragment left quite a deep wound on my forearm, I was lucky that it was not in the eye, be careful, Safety is paramount!)
For a start we will decide on the body. As an option, the use of the case from the burned Odyssey U-010, disappeared immediately, due to the size of the case with a small bedside table (460x360x120). Something more compact will suit us. At first I looked in the direction of the aluminum cases, but quickly refused the idea due to the price of these same cases. Those that I liked from $ 100, which already does not fit into the "budget amplifier". Therefore, an intermediate version of the "temporary" cheapest case was chosen, in which it has been standing for 6 months already. This body was the "Z16 Black" (easily found in Google on this request).
Dimensions (H / W / L): 89 x 257 x 148
Next, it was necessary to determine the scheme itself, because under the TDA2050 there is a huge amount of them. The choice fell on the so-called “ Skif scheme ”. Yes, and the usual components, not SMD, became a plus for me, because there was no experience in SMD soldering and the soldering station itself, only a regular 40W soldering iron.
So, the scheme itself (the drawing of the board for this scheme can be downloaded from the link at the end of the article):
I draw your attention to the fact that this scheme requires BIPOLAR power.
The size of the finished board for one amplifier channel: 35x45mm (and they need 2), which is quite compact as a result.
So, for powering 2 channels of 32 W each, we need 64 W (although this is all conditional and can be less). By happy coincidence, a transformer -287-220-50 with a capacity of 90 VA was lying idle in the bins , and it was easy to take off the bipolar power from it. Photo and scheme:
In order to remove from it at 35.26 V AC with a midpoint, it is necessary to connect the pins with the numbers: 12-15, 11-20, 13-18, 14-21, 17-16, and we will remove the voltage from 16, 19, 21 conclusions.
Next, the rectifier circuit:
Here is an example of the board itself. Although I did it, just by drawing a permanent marker on the textolyte, and etching it, without any LUT. It's pretty simple.
In the case of transformer -287-220-50, it is necessary to connect the 16th output of the transformer to the “middle point” input of the rectifier board. 19 and 21 in the remaining two, which one you decide where, and solder the jumper from the midpoint input to the area between the capacitors. After connection, you can check the voltage at the outputs of the rectifier. Between + and - should be from 42 to 50 V, depending on the voltage in the network. Between "+" and the earth, as well as the earth and "-" should be the same value. If you do not have any of the elements for the rectifier, then do not rush, as we will deal with the amplifier board, we will go to the radio market to take everything in a heap. The list of all elements will be further in the text.
To begin with, we are targeting two such boards:
And while they are being poisoned, we can go to the nearest radio component store or radio market.
So, we need the whole amplifier:
Power Supply:
The amplifiers themselves (everything is calculated on 1 board, respectively, take 2 times more):
Capacitors email Lytic:
Ceramic capacitors:
Film Capacitors:
Resistors (all 0.125 W each, and R6 and R7 2W):
And of course the TDA2050 itself, take 3 pieces, so that there would be a reserve, but it is not enough.
You will also need:
Then we drill and assemble according to the scheme. It all worked right away for me, only there was a crash in the speakers, but I will tell about this later. The only thing I want to notice is radiators. I went the easy way and just cut, with a regular hacksaw, an old radiator from some kind of AMD in half, and for each half I screwed the microcircuit, pre-drilled and cut the thread. That's just my chips are not located on the boards themselves, but on separate radiators, connected to the boards with small cables like this:
And the coil L1 according to the scheme is wound very simply, take one core from a twisted pair, and you wind 5 turns directly on the resistor R7, solder the ends to the terminals of the same resistor.
That's all, with electronics finished, by this moment you should have 3 boards ready: a rectifier and 2 identical amplifier boards for both channels.
And after that we can start assembling all this already in the case. So, for the beginning it is better to mark and drill holes for mounting boards, transformer, radiator cooling circuits, inputs and outputs. By the way, if you bought a rectangular switch for your amplifier, there is a small hint, as it is easy to make a hole on the panel for it. To begin, mark the dimensions of your future hole directly on the panel, and drill a thin hole inside the perimeter of the hole with a thin drill. And now the most interesting thing: take the most ordinary cotton thread (preferably thicker, the thin one often breaks in the process), pass it through the hole and, having pulled the thread, you can cut any shape like a jigsaw. That's just a jigsaw you cut, but here, as if "melted." That is why it is better to cut a slightly smaller hole, which would then bring the file up to an even file. It is also advisable to make vents near the radiators. I was reinsured and put another cooler, which turned out to be useless, the amplifier is not very hot even at maximum volume. I turn on only when the amplifier in the summer on the street works.
My layout looks like this (and although a bunch of wires are not beautiful at all, but everything has been working like a clock for six months already with regular use):
The leftmost board is the rectifier, the other 2 are amplifiers.
That's it, you can start to collect and solder. I soldered right in the case, without any clips, plugs and other things. Perhaps someone wants to make everything more convenient.
Wiring diagram volume control (two resistors - this is one double):
Key recommendations:
In the end, it looks like this:
Costs:
Total $ 17 and a lot of positive emotions "It works!"
Archive with all schemes and drawings of boards in Sprint-Layout 6 format: dl.dropbox.com/u/47591852/usilitjel_habr.rar
PS This is my first working device, assembled to test performance and reliability. In the near future I plan to recycle it in a new building and in a more accurate performance. If you are interested, it will be a continuation.
Here come the old Soviet speakers S-50 (if my hands reach, I want to upgrade them, but so far there is, that is), their TX:
- Passport electrical power not less than 50 W
- Rated electrical power 25 W
- Rated electrical resistance 8 ohm
- The frequency range is not 40-20000 Hz
And with them I got a great amplifier Odyssey U-010, which burned down. Having examined it, I realized that I would not do anything with my scanty experience. Touched Google a little, looked at the profile sites and here it is a solution - we will make ourselves an amplifier based on the TDA2050 chip as a replacement for the old one. For " Handmade and DIY forever, " and not so difficult. TX TDA2050:
- 32W rated output power
- Integrated short-circuit protection
- Integrated overheating protection
- Power supply up to 50V from unipolar power supply
')
(Immediately, I might have come across a fake, but with a short circuit, one TDA2050 exploded so that a chip fragment left quite a deep wound on my forearm, I was lucky that it was not in the eye, be careful, Safety is paramount!)
Housing
For a start we will decide on the body. As an option, the use of the case from the burned Odyssey U-010, disappeared immediately, due to the size of the case with a small bedside table (460x360x120). Something more compact will suit us. At first I looked in the direction of the aluminum cases, but quickly refused the idea due to the price of these same cases. Those that I liked from $ 100, which already does not fit into the "budget amplifier". Therefore, an intermediate version of the "temporary" cheapest case was chosen, in which it has been standing for 6 months already. This body was the "Z16 Black" (easily found in Google on this request).
Dimensions (H / W / L): 89 x 257 x 148
Scheme
Next, it was necessary to determine the scheme itself, because under the TDA2050 there is a huge amount of them. The choice fell on the so-called “ Skif scheme ”. Yes, and the usual components, not SMD, became a plus for me, because there was no experience in SMD soldering and the soldering station itself, only a regular 40W soldering iron.
So, the scheme itself (the drawing of the board for this scheme can be downloaded from the link at the end of the article):
I draw your attention to the fact that this scheme requires BIPOLAR power.
The size of the finished board for one amplifier channel: 35x45mm (and they need 2), which is quite compact as a result.
Power Supply
So, for powering 2 channels of 32 W each, we need 64 W (although this is all conditional and can be less). By happy coincidence, a transformer -287-220-50 with a capacity of 90 VA was lying idle in the bins , and it was easy to take off the bipolar power from it. Photo and scheme:
In order to remove from it at 35.26 V AC with a midpoint, it is necessary to connect the pins with the numbers: 12-15, 11-20, 13-18, 14-21, 17-16, and we will remove the voltage from 16, 19, 21 conclusions.
Next, the rectifier circuit:
Here is an example of the board itself. Although I did it, just by drawing a permanent marker on the textolyte, and etching it, without any LUT. It's pretty simple.
In the case of transformer -287-220-50, it is necessary to connect the 16th output of the transformer to the “middle point” input of the rectifier board. 19 and 21 in the remaining two, which one you decide where, and solder the jumper from the midpoint input to the area between the capacitors. After connection, you can check the voltage at the outputs of the rectifier. Between + and - should be from 42 to 50 V, depending on the voltage in the network. Between "+" and the earth, as well as the earth and "-" should be the same value. If you do not have any of the elements for the rectifier, then do not rush, as we will deal with the amplifier board, we will go to the radio market to take everything in a heap. The list of all elements will be further in the text.
Amplifier
To begin with, we are targeting two such boards:
And while they are being poisoned, we can go to the nearest radio component store or radio market.
So, we need the whole amplifier:
Power Supply:
- Al. Lytic capacitors of at least 10 000 uF x 25 (or more) V
- Almost any diode bridge, up to 10A (with a huge margin) and more than 50 V. (I took 10A and 400V - it costs a penny)
The amplifiers themselves (everything is calculated on 1 board, respectively, take 2 times more):
Capacitors email Lytic:
- C7, C8 - 1000 microfarad x 25 V
- C3 - 22µF x 25 V
Ceramic capacitors:
- S2-220pF
Film Capacitors:
- C1, C4, C6 - 4.7 microfarad
- C5 - 0.47 microfarad
Resistors (all 0.125 W each, and R6 and R7 2W):
- R1, R3 - 2,2k
- R2, R5 - 22k
- R4 - 680
- R6 - 2,2
- R7 - 10
And of course the TDA2050 itself, take 3 pieces, so that there would be a reserve, but it is not enough.
You will also need:
- 2 RCA inputs,
- 4 clamps under the outlet
- switch
- and a dual 50 kΩ variable resistor
- the knob of the regulator to this same resistor (but I just removed the aluminum from the old radio)
- Radiator from the old processor (if you do not have unnecessary)
Then we drill and assemble according to the scheme. It all worked right away for me, only there was a crash in the speakers, but I will tell about this later. The only thing I want to notice is radiators. I went the easy way and just cut, with a regular hacksaw, an old radiator from some kind of AMD in half, and for each half I screwed the microcircuit, pre-drilled and cut the thread. That's just my chips are not located on the boards themselves, but on separate radiators, connected to the boards with small cables like this:
And the coil L1 according to the scheme is wound very simply, take one core from a twisted pair, and you wind 5 turns directly on the resistor R7, solder the ends to the terminals of the same resistor.
That's all, with electronics finished, by this moment you should have 3 boards ready: a rectifier and 2 identical amplifier boards for both channels.
Layout and assembly
And after that we can start assembling all this already in the case. So, for the beginning it is better to mark and drill holes for mounting boards, transformer, radiator cooling circuits, inputs and outputs. By the way, if you bought a rectangular switch for your amplifier, there is a small hint, as it is easy to make a hole on the panel for it. To begin, mark the dimensions of your future hole directly on the panel, and drill a thin hole inside the perimeter of the hole with a thin drill. And now the most interesting thing: take the most ordinary cotton thread (preferably thicker, the thin one often breaks in the process), pass it through the hole and, having pulled the thread, you can cut any shape like a jigsaw. That's just a jigsaw you cut, but here, as if "melted." That is why it is better to cut a slightly smaller hole, which would then bring the file up to an even file. It is also advisable to make vents near the radiators. I was reinsured and put another cooler, which turned out to be useless, the amplifier is not very hot even at maximum volume. I turn on only when the amplifier in the summer on the street works.
My layout looks like this (and although a bunch of wires are not beautiful at all, but everything has been working like a clock for six months already with regular use):
The leftmost board is the rectifier, the other 2 are amplifiers.
That's it, you can start to collect and solder. I soldered right in the case, without any clips, plugs and other things. Perhaps someone wants to make everything more convenient.
Wiring diagram volume control (two resistors - this is one double):
Key recommendations:
- The outputs from the amplifiers should be made as thick as possible.
- If after the assembly and soldering in the speakers you hear a distinct noise - check the capacitors on the amplifier boards
- If the crash in the speakers, then check the power tracks on the amplifiers - I badly washed the acid flux, and if I looked in the dark I could see small sparks between the tracks, as soon as I cleaned the board from the flux, the crackle disappeared.
In the end, it looks like this:
Costs:
- All capacitors and resistors in the amount of $ 4
- Chips TDA2050 (3 pieces) - $ 2
- Case - $ 3
- All plugs, sockets, knobs, switches - $ 7-8
Total $ 17 and a lot of positive emotions "It works!"
Archive with all schemes and drawings of boards in Sprint-Layout 6 format: dl.dropbox.com/u/47591852/usilitjel_habr.rar
PS This is my first working device, assembled to test performance and reliability. In the near future I plan to recycle it in a new building and in a more accurate performance. If you are interested, it will be a continuation.
Source: https://habr.com/ru/post/162723/
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