Combo amplifier circuit for electric guitar. Guitar amplifier tube or transistor
November 17th, 2010
So. As I already wrote, I have been struggling with the search for about 3 months the best scheme and the most interesting sounding tube amplifier. The goal is to do it with the least loss, both financially and in sound quality. tube amplifier with your own hands. I tried several lamps different types and manufacturers, my first amplifier, actually assembled with my own hands, was a 2-tube 6p6s and 6n9s. 6p6s lamp (but it would be more correct to assemble an 18-watt marshal on lamps such as 6p14p, 6p14p-ev, 6p43p, and what about the original EL84) I really liked the sound best option for guitar. 6n9s is a double triode, so in order to save space we are replacing it with a 6n2p more modern brother. After playing for a month on a single-ended amplifier, I still realized that it was not. NOT ENOUGH! You need to stir up something more and louder. I read several dozen articles from forums, I understood the principle by which they work. I first tried a circuit with 3 lamps and then finally returned to a 4-lamp Marshall 18 Watt circuit.
Marshall 18 Watt Circuit
on Yandex.Photos
The circuits differ only in tone blocks, I personally did the same as on the bottom one, but I leave the choice up to you.
(to view in large size follow the link to the photo and select "in a different size > original")
The presented diagrams are Lite versions
IN general scheme as old as time, let's say it's a classic musical sound. One of the most common schemes of the famous company. This amplifier even has its own website with hundreds of replica options. And so, the process of purchasing and selecting parts began. At that time I had a couple of 6p6s lamps and a couple of 6n2p lamps before I bought the pads. Then I started looking for transformers. You can order the output transformer in the online store from Erasov, or try to find something similar on the breakers. I found a transformer on the radio market in Tsaritsino. I used TPP 245-127/220-50, the primary windings were just right for splitting into
half-cycles from the lamps, and the secondary ones are 15-16 and 17-18, that is, 10+10 volt
windings
To reduce noise immediately after diode bridge It is recommended to install a small throttle. I used D22, although it has a small current, nothing fatal happened to it. Lamps can be ordered either in the same Erasov or in the online store http://www.istok2.com/. We either buy all the related parts where we can buy them, or we assemble them ourselves.
Next we make the chassis. The chassis is the basis on which all installation is done. You can buy it, which is actually about $100, but you can make it from an old one computer case. Which is exactly what I did. He has an old AT body top cover and both walls are a single bent sheet. We measure out how much we need and saw off.
" " on Yandex.Photos
" " on Yandex.Photos
I made the power board on a PCB.
Don't forget about currents! So 6.3 volts would be enough for all the lamps. I had to buy a 4*6.3 transformer separately in order to power all 4 lamps. Also, don’t forget to shunt 6.3 volts to common “-”. Another recommendation for power supply I can only say is that, if possible, try to split the heat and 300V into different toggle switches. Since it is better to supply voltage to a warm lamp.
on Yandex.Photos
At first I was lazy and soldered it basically haphazardly. Everything is completely scary, the fog is buzzing, in short, chaos. So it’s better to do it right away and honestly. But at this stage it is recommended to decide where you will have what. And clean practical recommendations I can advise placing the lamps on the opposite side from the front panel. AND DON'T AT ANY TIME!!! case, do not paint if you are not sure. I'll have to disassemble everything and repaint the chassis!
The board can be made from anything, the main thing is that everything is clean and neat. and with the shortest distance of wires through which the signal flows. And just try to concentrate the power in one place and run all the wires along one bundle.
If we have collected everything and everything works for us, then it should look something like this.
(the article is not finished and will be added to, painting is ahead, assembling the head housing and cabinet, fine tuning and samples!)
Again, a recommendation: before drilling holes, think carefully or try on your knees what configuration you will end up with. To attach the chassis to the body, 2 boards were screwed to the side walls. DIY amplifier he actually assumes that you will do and redo everything 150 times if you don’t think everything through from the beginning.
Now a little about routing the wires. From my recommendations... immediately after the sockets, place a resistor on the common (-) 1 Mohm, mount it directly on the lamp legs, the wire from the sockets is strictly shielded.
The 6.3 volt filament wires must be woven into a tight braid (twisted pair).
We bring all common wires (ground) to one point, this installation is called a star. We take the wire from any old choke with a cross-section of 0.75, if you find it, the insulating wire should be made of varnish-kini, but in principle you can use any cambric without any problems.
Well, as I said, the chassis will have to be repainted.
In the end, I left only the master volume, and simply threw away all the other tinsel. 
To prevent current from getting into playful hands, I installed a grid. Regular garden mesh, bought at any construction market. For aesthetics it is painted black.
The side crossbars are screwed to the walls and the mesh is attached to them.
I remind you for those who have already lost their minds, we have been doing this for several months DIY tube amplifier for guitar.
Thanks to all my friends for your help and information. I give a few more links to articles from. At http://rumapucm.ya.ru the scheme was completely redesigned by me and from Light it was made even lighter.
Really awesome amplifier Marshall 18 watt Unfortunately, I did not assemble the original circuit, but replaced the output lamps with actual ones. Of course, this radically changes the sound, it’s still real Marshal 18 the amplifier is considered to be 6p14p (EL84)
Guitar amplifiers always attract increased interest among radio amateurs and musicians. The variety of tones, gain, and overload characteristics are always individual, and each guitarist has his own “ideal” requirements for each guitar. There is no amplifier that suits everyone's needs and this design is no exception.
The only difference is that you build it with your own hands. The design is designed so that you can experiment with each node and, in the process of modification, achieve the result you need. The design is based on standard, well-known diagrams of nodes and blocks. The design is easily repeatable, has increased reliability and is relatively inexpensive.
The amplifier has an output power of 100 W into a 4 ohm load, which is typical for a conventional “combination” in which two 8 ohm speakers are installed in parallel. You can also make an amplifier in a block with four speakers, connecting them in series and parallel, and the output power will be about 60 W (8 Ohm load). You can also use two speakers with four speakers each. In this case, you can achieve much better sound, keeping the output power at 100 W. This is a typical combination for guitar systems, allowing you to more fully use the capabilities of the main amplifier.
Preamplifier
The preamplifier circuit is shown in Fig. 1. The scheme has several features that distinguish it from the usual preamp typical ULF.
The preamplifier is designed in such a way that it allows you to obtain maximum gain and create a “juicy”, strong sound for lovers of forced sound. However, through adjustments, the preamp can be used for any playing style.
Likewise, by changing the tone settings, the amplifier can be used with any instrument: from an electrified violin to a bass guitar. Moreover, it should be noted that all these tools have different meanings output signal amplitudes, the preamplifier must therefore be adjusted during manufacturing to suit the intended application. Using all the capabilities of the preamplifier with careful tuning you can get high quality sound without specific low-frequency distortions that bass players don’t like.
From the diagram (Fig. 1) it can be seen that the preamplifier uses an imported low-noise operational amplifier. type TL072 specially designed for use in ULF input stages. This chip is easy to purchase in the markets nowadays. You can further reduce the noise level in pauses by using a dual mapo-noise op-amp 5532. It is more expensive than the TL072 and less accessible, but its use will ensure low level noise at rest. You can use domestic K544UD1 or K1407UDZ.
The signal from the output of the electric guitar is fed to the input of op-amp DA1.1, at the output of which a signal with a fast “attack” is generated. Frequency response The amplifier on the DA1 is deliberately limited to eliminate low-frequency distortion and “cut” high-frequency bursts, as well as improve the signal-to-noise ratio, which is not an easy task when creating guitar amplifiers.
Rice. 1. Pre-amplifier circuit
If there is no need to obtain the maximum gain of the cascades, it is necessary to increase the value of resistors R7 and R14, which will lead to a decrease in the gain and intrinsic noise. Switch SA1 additionally connects chain R3, C2 to the correction circuit, which shifts the frequency response of the amplifier towards higher frequencies, increasing the brightness of the sound of the electric guitar. By changing the position of the potentiometer sliders R9...R11, the overall frequency response of the amplifier path is changed. The narrowest band is obtained by setting the sliders of all potentiometers to the lower position.
At the output of the preamplifier there is a limiter assembled on diodes VD1 ... VD4. It allows you to perform a soft “trimming” of the amplitude of the output signal. For normal operation limiter, the output signal level must be at least 750 mV, therefore the overall gain of the preamplifier must be selected such that the output signal reaches the specified level in the middle position of the level control R12.
During installation, the input connectors must be reliably shielded. Proper grounding of power supply components also helps reduce hum. alternating current. Powering the preamplifier from a separate power source also helps with this. Branded guitar amplifiers often use this exact circuit design.
The “Hi” input is used to connect guitars with low output levels.
The “Lo” input reduces the sensitivity of the preamplifier by 6 dB by connecting resistor R1 to the housing through additional contact connector XS1, which closes if an electric guitar plug is not inserted into the “Hi” input.
Amplifier
The circuit of a typical low-frequency amplifier with a differential stage is taken as a basis. The circuit (Fig. 2) was designed to produce an output power of 100 W and showed good results when tested. Of course, in terms of sound quality it is inferior to a tube amplifier, but somewhat better than a conventional transistor amplifier. The amplifier has protection against short circuit at the output, made on transistors VT4 and VT5. At short circuit output of the amplifier, the voltage drop across resistors R20 and R21 exceeds 7 V (normal value at peaks of maximum output power). This voltage opens transistors VT4 and VT5 and they accordingly close the transistors of the output stage. This may not be the best protection circuit design, but it allows you to protect expensive output transistors from instantaneous breakdown in the event of a short circuit. The amplifier was not designed for overload operation, so the output current is limited to about 8.5 A.
At the amplifier input there are additional “Output” and “Input” sockets. The latter is switched by the contacts of the XS3 socket, so that it is possible to connect an external effects unit. Also, the input jacks can be used to connect an external preamplifier, respectively, disconnecting the internal one, and use only the PA.
Various high-power transistors can be used in the output stage. The use of transistors of the KT818GM and KT819GM types made it possible to obtain high reliability of the output stage with a fairly light operating mode of the output transistors. In addition, there is no need for temperature protection of output transistors, since when using two parallel-connected transistors in each arm, the thermal regime does not exceed the maximum permissible.
Rice. 2. Diagram of a typical low-frequency amplifier
A good result is obtained when using any powerful transistors made in the TO-3 package (this case has a lower thermal resistance). There is enough on the market wide choose imported and domestic power transistors that can be used in this circuit. The amplifier works well with any, if their characteristics are not lower than those shown in the diagram. To prevent failure of the output stage, the operating mode of the transistors is selected in their area safe work. Diodes VD2...VD3 must be silicon type D223, KD503, KD509 or others similar. Transistors VT6...VT11 must be installed on radiators. The “Line out” signal is approximately 1.3 V and can therefore be fed directly to a recording console or other device. The output signal level from the linear output can be changed by selecting the value of resistor R22. Resistors R20...R21 with a resistance of 1 Ohm are designed for a power dissipation of at least 10 W. Even with such power, they get very hot, so during installation they must be installed away from the rest of the circuit parts. They can be installed on small heatsinks or on output transistor heatsinks if the latter provide additional heat dissipation (each resistor adds about 10 W of thermal power). Resistors R16...R19 with a nominal value of 0.1 Ohm and a power of 5 W each.
The operating conditions of a guitar amplifier are very harsh, so you should not skimp on the size of the radiators used. Use the maximum radiators available to you for this purpose and thus you will increase the reliability of your design.
You can connect two speakers of 75... 100 W, 8 Ohms in parallel (RH = 4 Ohms) or 1 speaker of 150... 200 W, Rh = 4 Ohms to the amplifier output. With a load resistance of Rh = 8 Ohms, the output power of the amplifier is reduced to 60...65 W.
power unit
Be careful when designing your AC power supply as... Violation of safety measures can lead to injury electric shock.
The power of the power transformer T1 of the power supply (Fig. 3) must be at least 150 W. If possible, it is better to use a toroidal one - it has a smaller dispersion field and smaller dimensions with the same power. The primary winding is protected by fuse FU1, rated for a current of 5 A. A bridge rectifier for a current of at least 5 A is installed on the radiator. Powerful zener diodes VD9..VD10 for stabilization voltage ist = 15 V are also installed on small heat sinks along with current-setting resistors R2 and R3, away from the rest of the circuit elements, because During operation they become very hot.
The node on the elements VD5...VD8, R1, C1 is designed to separate the “electrical” ground of the circuit and the network grounding loop in order to prevent the background alternating current from “creeping” from electrical equipment and to protect the guitarist from electric shock in the event of a malfunction of the power transformer of the power supply . Resistor R1 with a nominal value of 10 Ohms prevents AC hum, and capacitor C1 with a capacity of 0.1 μF serves to eliminate radio frequency interference. In the event of damage to the power transformer (breakdown of the mains winding to the secondary or to the housing), the diode rectifier short-circuits the current generated by the damage to ground and thus protects the guitarist from injury. Despite the fact that this malfunction is extremely rare, it is better to protect yourself from the beginning when designing an amplifier. In general, when creating structures that are supposed to be used in “harsh” conditions (namely, guitar “combs” belong to these), issues of electrical safety should be treated with increased attention.
After completing the installation, make sure that all live wires connected to electrical network, carefully insulated and securely fastened. The wire connected to the loop grounding must be connected to the chassis of the structure through a separate bolt (bolts securing circuit elements cannot be used for connection).
Rice. 3. Power supply diagram
The wire is connected to a separate grounding bolt between two washers and tightened with two nuts (the second is a lock nut) to prevent loosening of the fastener due to vibrations during operation. The amplifier can be placed in the housing of one of the speakers or assembled as a separate structure. In any case, installation and design must be done very carefully.
Speaker design can be very diverse and depends on the dynamic heads used.
The proposed design options for the speakers were repeated many times and showed high performance characteristics. Both options are based on the principle of open acoustic systems. This eliminates the body's own resonant frequencies and, when using modern mid-frequency dynamic drivers, allows one to obtain high quality sound.
The first option (Fig. 4) is one column in which two dynamic heads of 75...100 W (RH = 8 Ohm) each are installed. The use of such powerful emitters is, again, associated with an increase in the reliability factor and the desire to have some power reserve. When using 50 W, 8 Ohm emitters, the speaker will operate in extreme mode, and reliability will sharply decrease.
The second option (Fig. 5) is the use of two speakers with 4 speakers of 35...50 W (Rh » 8 Ohms) each. When connected in parallel total resistance load is Rh=4 Ohm, the electrical power remains equal to 100 W, but the sound quality is much better.
The speaker enclosures are assembled from MDF panels with a thickness of 22...25 mm. The use of MDF allows us to obtain a mechanically strong, durable structure that is little susceptible to strong vibrations.
Rice. 4. Speaker design options (one column)
Rice. 5. Speaker design options (two speakers)
If you use conventional chipboard (which is somewhat cheaper), the service life of such a housing is significantly reduced, especially if the amplifier is designed to work with crossings on different scenes and sites.
All elements of the body are glued and fastened with special furniture bolts with a T-shaped nut. This increases the mechanical strength and durability of the housing. In addition, wooden blocks with a cross-section of 25x25 mm are glued and screwed to the inside of the ends. Special attention You need to pay attention to attaching the dynamic heads to the front panel. The heads should be fastened with bolts and nuts, not screws. A gasket made of soft material (for example, rubber or plastic) must be laid between the speaker and the head to ensure a tight connection. When working with MDF, you must carefully mark and prepare holes for fastenings using a drill. This will prevent damage to the section plane of the slab. The quality of MDF panels allows you to do without external finishing; only the end planes need to be sealed with a special tape, which is sold along with the panels.
The world's first magnetic pickup was designed by the talented engineer Lloyd Loehr, who worked at Gibson in 1924. The first samples of electrified instruments did not produce the desired effect among musicians, and mass-produced electric guitars appeared only in 1931. The electric guitars of the Electro String Company, which, by the way, looked more like a banjo, were jokingly nicknamed “frying pan” by the musicians.
The principle of operation of a magnetic pickup, now familiar to anyone who has taken a school physics course, has not changed to this day.
The advent of the guitar amplifier
The appearance of the guitar amplifier was made possible thanks to the very idea of increasing the volume of the guitar. Guitarists playing in ensembles were forced to increase the volume of their instruments so as not to get lost in the overall sound picture. Initially, there was no separate amplifier for an electrified guitar, and any amplifiers that were at hand were used. Experimenters of that time, gradually gaining experience, realized the promise of industrial production of guitar amplification equipment.
Over time, from small companies huddled in a garage or store basement, transnational companies were formed - manufacturers of professional musical equipment, proudly bearing the names of their “founding fathers.” In the world of guitar amplifiers, the words Fender, VOX, Marshall, Mesa Boogie, Orange have become household names, and the sound of these amplifiers has become a standard, which other manufacturers emulate and try to surpass.
Types of Guitar Amplifiers
- tube
- transistor.
- hybrid.
Guitar amplifiers can also be made in several versions:
- Guitar combo (the amplifier itself is built into the speaker system).
- Guitar amplifier head with sound system(office).
- Guitar power amplifier (in this version, the preamplifier and power amplifier block are made as a separate device).
Each version of a guitar amplifier has its pros and cons: the classic versions of “that same sound” are just guitar amps or guitar amplifiers with cabinets (they are also called a guitar stack), but they are usually very bulky and inconvenient to transport. In contrast, rack units take up less space and can be wired in different ways, but they don't look "cool" on stage during concerts.
Regardless of design, guitar amplifiers come in different capacities. This could be a 10-15 watt unit (often such devices are used in not very large recording studios, when the volume is not the highest important parameter) and a 50-100 watt tube monster (these are the kind of stacks and combos that can be seen at large stadium concerts on the stage behind the guitarist). Today there are even 1-watt devices for the home, for the family, so to speak.
Before using any electrical device Please read the user manual carefully. Before connecting for the first time, I would recommend checking whether everything is in order with the amplifier, whether the speaker is connected to the amplifier output, and whether there is any structural damage to the case. It is necessary to clarify the operating voltage of the amplifier (amplifiers and combos designed for the American network operate from 110 volts; they can only be connected to our network through a special step-down transformer).
Also, it is advisable that the network be grounded, otherwise you risk getting an electrical injury (the strings of an electric guitar through the metal bridge are in contact with the grounding of the electrical circuit, and if you hold the strings with one hand and the radiator with the other, you can get an electric shock), and the sound will leak extraneous noise. If this is a tube combo or amplifier, you need to make sure that during transportation the radio tubes have not jumped out of the contact panels (it is enough to look into the amplifier or combo through the technical holes and, if necessary, correct crookedly installed radio tubes).
Before turning it on, I would recommend turning the overall volume down to zero, and setting all other controls to the 12 o'clock position (this does not mean the division of 12, but the conventional clock dial). From this position it is easiest to control the sound. In a tube guitar amp, you usually need to press 2 switches (power and stand by) to turn it on. Moreover, first you need to turn on the power and then after 2-3 minutes stand by; you need to turn off the amplifier or tube guitar combo in the reverse order (stand by is turned off first and then power).
In addition to the switches on the front panel of the guitar amplifier, there are overall volume controls, high, mid and low frequency controls, and a gain control. Sometimes there is a presens regulator (more precise focusing high frequencies). There is also a channel switch on the front panel (if the amplifier is more than single-channel).
On the back panel of the guitar amplifier there are: an output to the cabinet (you need to remember that you can connect to the amplifier to a cabinet matched in resistance), outputs to the effects loop (when you can connect different, usually spatial effects or processors to the amplifier), an output for connecting a control pedal (them you can switch amplifier channels or turn on the reverb effect if it is built into a guitar combo) sometimes on the rear panel you can find a cabinet emulation output (this output can be connected directly to a mixer or recording device).
Modern industry offers guitar amplifier combos with built-in effects.
Such combos are convenient due to their compactness and mobility. There is no need to buy a bunch of different ones separately guitar effects, connecting wires, power supplies for effects. On my own behalf, I can add that the sound of expensive units will be at the same level, and as a result, the price will be the same.
Unfortunately, Chinese guitar amps cannot boast of this.
The main differences between tube and transistor guitar amplifiers
A transistor guitar amplifier is relatively cheap to make, lightweight, and its low output impedance makes it easy to pair with any low-impedance speaker. The radio components from which it is made do not require periodic replacement, are not harmful to a transistor guitar amplifier, and the “microphone effect” (an undesirable phenomenon in which some part electrical circuit perceives sound vibrations and vibrations like a microphone). In addition, transistor guitar amps often have a headphone output built in, so you can play the guitar without disturbing anyone in the first hour of the night.
A tube guitar amplifier, unlike a transistor one, has an output resistance of up to several tens of ohms, so the sound is affected by both the quantity and quality of the output stage tubes and the quality of the output (matching) transformer (the cost of the output transformer alone can be commensurate with the price of an average transistor amplifier ). In addition, unlike a transistor amplifier, a tube unit is repairable even in the field (while a transistor amplifier can be repaired, additional devices and tools are required). But the main thing is the sound that a tube guitar amplifier produces; in general, the sound of a tube guitar amplifier is better to hear once than to read its description ten times. I note that 99 percent of guitar music is recorded using tube guitar amplifiers.
And a little about companies producing guitar amplifiers
Fender
The oldest and one of the most respected guitar amplifier manufacturers, founded in the late forties in North America, began mass production of guitar amplifiers named after itself in 1947. It is noteworthy that the first samples of Fender amplifiers were copies of Western Electric radio equipment. Initially, absolutely everyone played Fender amplifiers (there were simply no other guitar amplifiers). Until now, the clean sound of an electric guitar is usually compared to the Fender Twin Reverb.
Marshall
The founders of the British sound and mastodons of rock sound (even those who don’t know what a guitar amplifier is are familiar with this logo). According to legend, Jim Marshall (founder of the company of the same name) copied amplifier circuits from Fender, but one day he either made a mistake or deliberately changed the circuit, and as a result, original and fairly recognizable tube guitar amplifiers appeared. The first production Marshall amplifier, the JTM45, was a copy of the Fender Bassman '59 56F-A.
This one was particularly loved by the famous left-handed virtuoso Jimi Hendrix.
VOX
The British company "vox" was born in the 50s in Britain, their amplifiers VOX AC 30 and AC15 were loved by more than one generation of rock stars. The abbreviation “AC” meant that it runs only on alternating current (Alternating Current) - this was a revolutionary idea at that time.
Mesa/Boogie
Initially, the American Randall Smith was engaged in refining Fender guitar combo amplifiers. The first combo was released in a Fender Princeton body, Smith replaced standard speaker for a larger speaker, modified the chassis and installed an output transformer from a Fender Bassman. Smith tested his amplifier in a local store, in which, by coincidence, Carlos Santana, who is responsible for the saying “Man, that little thing really boogies!” to Randall's amplifier. The issue with the name has been resolved). The company produced the first serial amplifier in 1971, the Snakeskin Mesa 450. The real breakthrough for the company was the accidentally discovered effect of heavy amplifier overload, as a result of refining the preamplifier circuit. Based new scheme the Mark I combo was made.
It should be noted that today there are a lot of companies producing guitar amplifiers. But everything is based on the classic circuits developed in the 50-70s, the whole secret of those same legendary amplifiers lies precisely in the fact that the first samples of guitar amplifiers and combos were assembled by enthusiasts entirely by hand, the master put a piece of himself into each of his masterpieces. This is precisely why particularly picky connoisseurs of guitar sound try to have original (even shaggy years old) amplifiers in their arsenal, and not modern consumer goods and reissues of legendary amplifiers released in our time in the Asian region.
Hybrid guitar amplifiers and combos are considered a compromise option today. A hybrid guitar amplifier usually has one or two radio tubes in the preamplifier block, and the power amplifier block is built on transistors and microcircuits. This type amplifier is another trick of marketers in pursuit of customers. The sound of such amplifiers is objective (in a number of purely technical reasons) is worse than that of tube amplifiers, but the manufacturer writes in large letters something like “patented technology, true tube sound,” guitarists themselves joke about such devices: “a lamp in it for illumination.” You need to understand that any really cool thing costs a lot of money, although of course you can console yourself with hopes that the “light bulb” in the preamp makes the difference.
- If you are a beginner guitarist, take a transistor combo/amplifier (it won’t be such a shame to spend money on a “serious tube” if suddenly you don’t want to play in the future.
- If you have been playing for some time and the transistor is no longer enough for you (or you think it’s not enough), buy a simpler tube amplifier. Modern famous brands have inexpensive lines of tube guitar amplifiers produced in the Asian region.
- Do not neglect the domestic manufacturer: firstly, the quality of manufactured products from the same YERASOVs has increased greatly, and secondly, modern radio components that are found in expensive branded devices are produced in China, and I consider overpaying for a “cool” inscription an unjustified waste of money.
- Don't take the most powerful amplifier; you're unlikely to immediately play stadium rock vestals.
- Always listen to the amplifier in a store before purchasing (if possible). Today there is plenty to choose from, and the fact is that the legendary amplifier that your friend likes will delight you too.
4 0
The other day I completely ran out cash. I am a student and spend all my time studying. You won’t make much money anywhere. But life gave me a guitar and the ability to play this tool. So I decided to make some money. I walked around the city, played and made money from it. There was no particular profit, but I really liked this activity. A cheap guitar pickup was sent from China. All that was left was to purchase a sound amplifier. The cheapest branded one I found cost $150. I don’t have that kind of money, so I set a goal to build the amplifier myself - to make it cheaper.
Scheme
For this purpose, I didn’t overclock the power too much and chose a simple amplifier based on the TDA8560 chip. This microcircuit costs about $3. ULF circuit It is very simple and can be assembled using a hinged method. That's how I did it the first time. The microcircuit must be attached to a rather large radiator. To avoid installing additional elements cooling. The power wires must be thick to prevent them from melting and short-circuiting the system in the future.
The chip itself contains several protections. She is not afraid of overdoing it. overexertion, but still you shouldn’t torture her and experiment. All other elements are very easy to find in old radio equipment. All of them total cost will not exceed $2.
Later I transferred my device to a printed circuit board, since long trips around the city significantly weakened the structure inside the speaker. I made the printed circuit board using the laser iron method; there are quite a lot of articles on this topic on the Internet.
All parts were carefully soldered and did not overheat during this operation.
I installed a radiator. I connected the speakers to the circuit, made a 3.5 mm jack for music input (for a guitar pickup), and connected the battery.
All this was neatly arranged in the case old column. The total weight was approximately 8 kg. My speaker is only 45 watts.
The amplifier outputs 50. I don’t even load it too much. Works great. Pleased with the simplicity and assembly diagram. The battery is a regular gel lead battery, 12 V.
Total
Total cost $10. Benefit relative to purchase ready-made kit- $140. Now everyone can hear me and people don’t pass by). At minimal cost I received maximum effect and pleasure. Choose for yourself what to spend, 150 dollars or one day of your life. Good luck to everyone) AptuneR.