For the garage and beyond. “Kolhozim” universal stereo for pennies
Owning movable and immovable property necessarily leads to the overgrowth of all sorts of junk: what does not fit in the apartment – goes to the country, what is not needed in the car – settles in the garage. There are many scenarios, but the necessary-unnecessary things can wait for years for their finest hour. Today let’s turn our attention to old speakers that many people have lying idle.
The most obvious option is to bring them back to life with some “stereo”, preferably with Bluetooth. The cost of the most budget models starts from about $15, and you will not find wireless connection in old devices. Not our option! But a module from China for $ 3 – it is the best.
There are dozens if not hundreds of similar modules on sale, and it is even impossible to count the number of already sold ones. We chose a universal version with built-in amplifier, working at 5 to 12 volts. Can we make something smart?
The package is rich: besides the module itself the package includes wires with pads for connection to the board, a remote control (the battery is not cheap) and two soft plugs which help to hide screws sticking out from fixings. The set of interfaces is from the “all-inclusive” category. USB, memory cards, AUX and Bluetooth – other automobile multimedia systems offer even less.
About matching capacity of speakers and amplifier we suggest you to forget – this story is about something else entirely. Connection is very simple: all you have to do is to supply power with observance of polarity and connect the speakers themselves, again not mixing “plus” and “minus”.
After welcoming “HI” on the crooked screen the “boombox” is ready for operation. Basic control is available through the buttons on the module itself – this is the selection of the playback source, volume control and changing tracks/radio stations, as well as turning on the pause.
With the remote control everything is more interesting. With it, you can immediately specify the number of the radio station or track, mute with one button and even play with a few preset equalizer settings. The remote control, of course, does not make you feel like a “thing”, but it is really more convenient to use. For power it is declared a CR2025 battery, but a puffier CR2032 will do.
There is no problem with the power supply of the module itself – it works on what you have on hand. According to multimeter readings, the device starts at 4.2 volts. Both an old power supply from a computer and an unnecessary charger for a cell phone will do. In our case with two connected speakers and the radio at maximum volume the peak current was up to 0.5A, so it is better to calculate with a reserve. If you have batteries like 18650, the “boombox” can be turned into a monster analog of wireless speakers.
We will characterize the sound quality as not bad. Audiophiles will not appreciate such devices in any case, but for listening to music in the same garage, the “boombox” will do more than that. Extraneous noise is not heard, the volume reserve, if not to arrange a very noisy disco, is sufficient. Last but not least, the sound will depend on the speakers themselves, as well as on the box for them.
The module recognized several “flash drives” formatted in FAT32 without any problems, quickly connected to the smartphone and caught several radio stations without the connected antenna as such. Another important factor is that the device remembers the volume level and playback source even after power is turned off. In reviews of other models there are often complaints that the modules have a habit of turning on at maximum volume. If you decide to order something like this, just do not be lazy to study the experience of other buyers.
During several hours of testing the device has not caused any serious criticism. It may be plain and with a purely “Chinese” look, but that did not prevent it from solving the tasks assigned to it. Music does not “stutter” from any sources, you can power the “boombox” from almost anything, and any local overheating was not detected. In addition, with the help of the module you can easily upgrade already obsolete tape recorders and music centers – then “kolhozing” is reduced to a minimum. Perhaps that was the most useful $3, which went to the account of Chinese sellers.
Taking pictures and listening. VCRs and car stereos in the Autobusiness ad database
What you can make from a car radio
In this video tutorial will show you what you can do with an old car radio, which can be in your garage, waiting for dumpster. But with skilled hands and with a clever head you can attach a block to it from the same old unnecessary personal computer and the garage will play music from the restored radio and CD player.
A car stereo is a great device for receiving radio stations. This is because they are made powerful to provide confident reception when driving on the road.
Boombox from a car radio. Homemade audio system
Sergey Sergei A year ago I made a similar boombox for my dacha. I did not buy anything, made it from chipboard scraps and “waste products” of car audio and computers. I took the power supply from the computer, the car stereo and the speakers from the auto music upgrade. Holes of the phase-inverter were not calculated, I just made 4 pcs. of 25 mm each (what kind of drill was there). Yes, and put the active antenna inside, also picked up “from the floor”. The grids for the speakers (do not laugh) were also in my corner with the junk. Only pity the old radio without remote, but it sings great! But the video review did not do. Props to the author – set an example to people, and stirred up the comments.
Sergey Buy another universal car charger (for different phones) solder to the power supply and put it in the compartment for mobile devices and when listening to music through AUX time will not be limited by the battery charge phone or player.
Art Mabut 3 years ago Well done, such hands are really golden! All perfectly done, thought-out much, even the backlighting is, battery + AC adapter. Your device is much better than the mountain of Chinese plastic for 12 thousand rubles.
I had a stereo with a burnt CPU. I decided to turn it into an amplifier) tda7388 chip. Max power 41 watts per channel, only 4 channels.
In principle there is nothing complicated here, saw out the amplifier from the radio board, wired up the missing parts and wires according to the schematic, put it in the case and that’s all.
If you want to use this amplifier in the car, you don’t need to connect the wire, where it says ST-BY, to the plus, it must be taken out and the control plus from the radio (the one that goes to the antenna or amplifier, usually a blue wire) must be fed to it.
The amplifier is not bad, but unfortunately in the world it did not come out, because when debugging, I mixed up plus and minus and burned it ((( But somewhere I have still one boombox lying … )))
See you all soon, I will write SOON)))
Good idea! I have an Opel Siemens NCDC 2013, it has a good amp can I use it to amplify my car?
I need to see what kind of chip is in it.
Take some time for my questions?!)
I will try.) No promises though. Work…
www.drive2.ru/l/288230376…age=1#a518504945721278465 Here is such a headset and on the principle as described soldered RCA cable but phoned.
Thanks for the article. I understand that I can repeat the same thing? The amplifier is usually on a separate board or along with the main board? I have a cassette recorder with an amplifier (with it I want to remove) and a car audio equalizer alpine without an amplifier ( only the line outputs).
Hi, can you advise which amplifier to make for a sub with speakers from s-30 10GD-34-80
Well, from these dinov normal sub does not get, here I experimented (I immediately respond to your comment), there amplifier from the radio, ie, about 20 watts per speaker, the speakers at the limit of its work worked. I tried to connect to more powerful, the same thing, as a result speakers burnt out, and the sound I did not get, and remade the box 5 times, all to no avail, as for home use will do, but for cars sucks a lot.
Hi, can you tell me about this? The screen is dead, but the sound and other things in memory are pressed and everything works. I had the idea to solder to the sound path to use the booster car to amplify the signal from the tablet (I want it in the car to put). The question is where to solder? Right after the cassette tsap? Or later before the amplifier part? I found the datasheet for the amplifier, I know exactly which legs go to the output.
What do you want it to do? To be just an amplifier? Without adjusting the filters?
I did it all already) This time it was fine, nothing burned out)))))
A boombox is an omni-wave tuner, a circuit for recording and playing back sound on magnetic tape, and a low-frequency amplification path. A tape recorder is often referred to as a cassette recorder without a radio receiver. Compact boomboxes are equipped with car showrooms. The most vulnerable place of such a device is the tape drive mechanism, the cassette receiver and magnetic heads, which wear out, while the low-frequency part remains quite functional. Therefore, it is not difficult to build a sound amplifier from a car stereo with your own hands.
How to make a sound amplifier from a boombox
Many car enthusiasts use the low-frequency amplifier from the car stereo to connect external sound sources to it. This can be a phone, smartphone or tablet. Connecting these devices can be implemented in several ways. The simplest option is to use a cassette adapter.
This device is a standard cassette with several plastic gears inside to simulate the tape drive and a magnetic head. A wire is soldered to the pins of the head, ending in a 3.5 mm Mini Jack connector. This connector plugs into the AUX OUT jack of any external device. The audio frequency signal from the source goes to the magnetic head of the adapter, which acts as a transmitter. The sound signal goes to the adapter head, and an alternating magnetic field is formed around it, which is perceived by the magnetic head of the car radio. Then the signal is amplified and fed to the car speaker system.
This design has the following advantages:
- low price;
- does not require a power supply;
- can be connected to any device;
- good quality of sound.
The main advantage of this device is that there is no need to open the car radio and solder additional wires. Almost any car owner can use a cassette adapter. The disadvantage is the need to turn the boombox into playback mode, with the sound of the tape drive mechanism and the adapter gears being heard. To get rid of this, it is enough to unsolder one of the motor power wires, as it is not needed in this design. The cassette adapter can be used with any car stereo.
If the cassette adapter assembly is broken, you can make a sound amplifier from a car radio in other ways. Older types of car stereos do not have an additional AUX-in input, but if it is present, it can be used to connect external sound sources. For this you need to buy a Wireless Bluetooth Music Receiver. It is a small plastic box with a Mini jack 3.5 mm plug. It is inserted into the input jack of the car radio. This device allows you to listen to music or radio broadcasting from any device via Bluetooth. Such a channel is equipped with all smartphones and tablets, as well as most models of older cell phones.
The adapter is available in two versions:
- with power from the cigarette lighter;
- With built-in battery.
The second option is preferable, since the car’s cigarette lighter jack usually powers the GPS navigator, and if you want to install a video recorder, you’ll have to put a splitter on the cigarette lighter. As a result, there will be too many wires. The system with a built-in battery or a lithium battery is free from these disadvantages. It is enough not to forget to change the power supply in time.
Another option is to use an FM transmitter. This device allows you to listen to music from external carriers, if your car radio is equipped with FM tuner. Transmitter is a link between the memory card with your favorite pieces of music and car radio audio amplifier. This device is powered from the cigarette lighter of the car. It has a small display on the front panel which shows the operating frequency.
The transmitter has a USB connector for flash cards and a slot for Micro SD cards. Some models are equipped with a remote control. The electronic unit of the transmitter converts the information recorded on the memory card into an analog high frequency signal in the FM band. Then the transmitting unit transmits the signal to the car radio’s FM receiver. The carrier frequency of the transmitter must be away from the frequencies of the transmitting radio stations to eliminate the influence of interference on the signal.
How to make a sound amplifier for a car radio on a chip
Some old boomboxes have no useful inputs like USB and AUX, so to use them as an amplifier you’ll have to take the device out of its seat and open the circuit board. If you are not experienced in working with electronic circuits, you should not take up this work. First you need to find the integrated circuit of the low-frequency amplifier on the car radio board. This is a large-sized part and the only one that is mounted on the heat sink. On the circuit diagram and on the board it can be labeled AMP or POWER AMP. Next you need to identify the input pins of the amplifier. There are two pins on the chip – the left channel input and the right channel input. The left channel can be labeled Line L or L-in, and the right channel can be labeled Line R or R-in. You can determine correctness by touching each pin with your finger. A hum will be heard in the corresponding speakers. The power to the car radio must be on. The ground or common wire is labeled Line GND.
If there is no marking on the diagram, you can find the channel inputs directly on the chip. To do this, you need to touch all the pins in sequence, focusing on the appearance of hum in the speakers. Do not solder the connector to these pins. It is necessary to determine the connection points of the isolation capacitors and already to them solder the wires.
The soldering of the channels on the plug and socket should be done with shielded wire according to the following scheme.
A self-made boombox sound amplifier can be used with any external sound source. There are no tone adjustments in such a design, because the signal is fed directly to the input of the termination amplifier, bypassing the equalizer. To reduce the noise level, the tracks going to capacitors C1 and C2 from the preamplifier of the playback head should be trimmed.
If you have a new boombox installed in your car, you can make a compact audio amplifier from an old one. To build an audio amplifier from a boombox, you need to remove everything superfluous and unnecessary.
You can see how to build a sound amplifier from a boombox in the picture. The ZXM8330-PA is built with two microchips and three transistors. The FM tuner is built on the chip TA2003 and the terminal amplifier on the chip TDA2003. The radio part and the first transistor in the preamplification stage of the signal from the magnetic head can be excluded at once. The power wire of the electric motor must also be cut. The printed tuner power wire, coming from the “Radio”-“Tape” switch, and the wire from the chip output to the collector of the second transistor are also cut. You can experiment with the rest of the circuit elements. If the external device, which will be connected to the amplifier, has a powerful enough output signal, then it should be connected to the upper pin of the variable resistor “VOLUME”
You can use the collector of the second transistor for the weak signal, that is the point where the tuner signal was fed. In this case the tone control and the volume limit switch “Mute” will work. The power supply circuit of the first and second transistors must be broken. In a car, all electronics are powered from the battery. If the amplifier is to be used as a stand-alone unit, it needs a simple 12 to 18 V power supply. The amplifier provides 6 W output power on a 4 ohm loudspeaker head and 10 W output power on a 2-ohm loudspeaker. The maximum current draw is 3.5A. According to a similar principle you can make your own hands amplifier from any car radio. The main thing is to correctly determine the input circuits and disconnect from the input all unnecessary stages, which may be a source of noise. Especially it concerns the amplification stages of the playback path. Working with stereo systems is a bit more complicated, but the methodology remains the same.