A simple stereo audio amplifier circuit discussed here is built around the IC TDA 1521, requires very few external passive components and is able to provide a powerful 12 + 12 watts of music output.
Main Features of the Stereo Amplifier IC
The IC contains all the built in features required for an amplifier circuit like automatic mute, overload and over heat protections.
The circuit of a stereo audio amplifier using IC TDA 1521 presented here is very simple to build, utilizes very few external components and yet is able to produce 12 + 12 watts of hi-fi music power.
The input can be from a CD player or your cell phoneBuilding a stereo audio amplifier usually refers to using two mono amplifiers and integrating their inputs, common ground and the supply to get the required stereo provisions.
However such circuits generally tend to become too bulky and moreover making identical modules simply makes everything double and thus the costs involved also get doubled.
But there are quite a few single chips available in the market which contains built-in dual amplifier blocks to make things really compact and sleek.
One such IC is the TDA1521 which is a dual high fidelity power amplifier chip embedded inside a 9-pin plastic encapsulation.
The chip is perfectly suited to be used with rough power supplies and indeed has rugged specifications.
How to Build the Amplifier Circuit
We will discuss how to make a simple stereo amplifier using this IC, but before that let’s first go through some interesting specifications of this device.
The TDA1521 basically produces optimum performance with dual supply voltages of around 16 volts and will deliver a good 2 × 12 watts of music thrust into a couple of 8 Ohms loud speakers.
The gain of the amplifier is internally calibrated and fixed at 30 dB with a space of 0.2 dB. This ensures a nice balance of gain in between its two channels.
The chip carries a special in-built music mute facility. The feature enables the IC to disconnect its non-inverting inputs when the supply falls below +/- 6 volts, although the amplifier remains successfully biased at this voltage.
The above property makes the circuit free from unnecessary clicking noises while switching the circuit ON and OFF.
Short Circuit and Overload Protection
The output of the IC is well protected against overloads and accidental short circuits.
The IC also includes a thermal runaway protection so that excessive heating of the IC will not damage it; however it may shut-off at high case temperatures.
Therefore it is recommended that the IC is fixed with a heatsink rated at 4K/W when the output is subjected to a 8 Ohm load @ +/- 16 volts supply.
Please note that the pin #5 of the IC is internally linked with the external metal tab over the IC.
Technical Specifications
The following data provides a few interesting specifications accompanied with this stereo amplifier chip:
Total Harmonic Distortion: 0.5% @ 12 watts,
Quiscent Current Drain is less than 40 mA,
Gain Balance is around 0.2 dB,
Supply Ripple Rejection is around 60 dB,
Channel Separation is @ 70 dB,
Output Offset Voltage is 20 mV,
Power Bandwidth (@3 dB) is 20 to 20000 Hz.
Circuit Description:
The stereo amplifier circuit shown is quite simple and is almost self explanatory.
As you can see this stereo audio amplifier hardly requires any components to become a full fledged stereo amplifier.
Just a resistor/ capacitor network to handle frequency compensation and a couple of input DC blocking capacitors is all that is needed to generate high quality stereo music from this little package….amazing indeed.
The whole unit of this stereo audio amplifier can be easily built over a general purpose board and the whole system along with the power supply may be enclosed inside a sturdy metallic box. Whether it’s your CD player or your cell phone, it will convert every bit of it into a heart throbbing true pulsating stereo output.
ARUN says
Sir I want to make a 5.1 hometheatre setup in my small room. I already have a Mackie professional studio monitor speaker pair currently using as stereo speakers. I have a Dolby 5.1 decoder audio gear which can create 5.1 tracks from any encoded Dolby audio track. So what I am planning is to buy a good quality 2.1 speaker system with powerfull bass and use the satellite speakers of it as Surround speakers in my new 5.1 system.. So a total of 5 speakers ( Front Left, Front Right, Left Surround, Right Surround and subwoofer ) will be there… The Centre channel is then missing… What I am thinking is Use the Front Left and Right Speakers together to create the centre channel effect as it is a studio quality one it can deliver good quality dialogues also…
Now the problem is ; my 5.1 decoder gear is having 6 outputs ( FL, FR, C,LS,RS ans SUB ).. how can I feed the signals to the Front left and right speakers to create the soundscapes of Front Left, Front Right together with Centre channel ? The left speaker has to feed the FL signal along with the Centre channel signal similiary the Right one FR signal with centre channel signal… My question is – Is it possible to feed each speakers ( FL, FR ) with the combination of the corresponding complex analog sound signal ? Is there any way for it without overloading or affecting each channel output from the 5.1 decoder gear ?
Swag says
I’m a sorry Arun, I have no clues regarding this, hopefully somebody else in this forum would be able to suggest something useful..
sanket kalyankar says
Hello sir i want an amplifier for my cR which vmcan work on 12v single power supply and atleast 30w power
Ainsworth Lynch says
is it possible to parallel transistors in this circuit I sent to get more power out say 600 watts, what would I need to do?
https://www.dropbox.com/s/epye1zn0c0hhkwu/200watt-anfi-devre-semasi.png?dl=0
Swagatam says
the image is taking too long to open…
Ainsworth Lynch says
Ok sorry about that this is my google drive link
https://drive.google.com/file/d/0B0N-CQJdWSP0RXBIWHZpclRRVEk/view?usp=sharing
Swagatam says
I am not sure whether the transistor can be paralleled in this circuit or not, normally transistors can be paralleled to increase power by using individual resistors at their bases, but in this deign I am not sure because of the IC in the middle.
Ainsworth Lynch says
the Ic in this article uses ± 21 V maximum would that be 42 volts accross the 2 end termials and 21v from end to center? Or is it that ± 21V is 10.5v from end terminal to center?
Swagatam says
it's 42V from end to end
Kanak Naik says
Well thnx , but now we are given an amplifier circuit from the net. Its a 20w stereo amplifier using tda7377. They have also used an irf1405 mosfet …. but I dont know why it has been used. I am not getting the irf1405 mosfet anywhere in the market….. what should I do?? Is there any other mosfet which I can use over there? Can u tell me what is the mosfet used as….. a voltage regulator or linear amplifier? Is there any alternative?
Thanks in advance. Regards.
Swagatam says
check the datasheet of the mosfet to find its voltage and current specs, any other mosfet with similar rating can be used as a replacement.
without seeing the diagram I won't be able to suggest much.
Kanak Naik says
How do i add bass and treble control in the circuit?
Swagatam says
You can do it as explained here:
https://homemade-circuits.com/2012/01/how-to-make-your-own-active.html
Kanak Naik says
Hi sir i am new to electronics. We are asked to make a battery operated dual audio amplifier for MOBILE PHONES in OUR electronic project. The above circuit is fine except that it uses mains supply and a transformer. Please suggest a good circuit with ALL POSSIBLE DETAILS AS I AM NEW TO ALL THIS. Thanks in advance.
Swagatam says
Hi Kanak,
you can operate the above circuit with a battery as well, however you will need two 12V batteries and connect them in series.
just remove the four diode bridge and the capacitor and the transformer and connect the battery as explained below:
The center series connection of the two batteries will join with the line which is marked with a "ground" symbol.
positive of the battrey will go to the pin7 of the IC and negative with pin5 of the battrey
Swagatam says
…sorry it's pin5 of the IC ….not the battery.
joshua richard says
hellow sir . i am new to electronics and i have been interested in amplifiers projects which they have been working well . But i have been facing problem of signal clipping mostly on small amplifiers such as tda 2822 even of higher such as tda2040 . how can i avoid this
Swagatam says
Hello Joshua, are you sure it's signal clipping? Did you check it with an oscilloscope?
TDA2030 will not have this problem normally, please confirm the fault once again….
Madamidola Olayemi says
Pls sir, help me with this questions:
1. Are all capacitor electrolytic?
2. Are those 100k presets?
3. Is there volume control in the circuit?
4. What is 10E and log dual.
Thanks alot.
Swagatam says
1. the one which is between bridge is only electrolytic erst all are ceramic disc.
2. 100K are pots not presets.
3. the 100k pots are the volume controls.
4. 10E = 10 ohms, log is the specification of the pots.
achilles hector says
thanks for the reply
no it says here:
Impedance: 4 ohms
Rated Input: 1.6 watts
made in japan
and its a casio product. A speaker from my mother's piano. :- )
I have another question.
1. Can I power the speaker (mentioned above) with 10 watts amplifier?
Swagatam says
I think you should use a smaller amplifier with this speaker,10 watts could damage it, you can try a LM386 circuit for it.
achilles hector says
good evening sir!!!
belated christmas and a happy new year!!
I have some doubts.
1. Do I need to use preamplifier before the amplifier?
2. Can I use 4w / 1.6 ohms Speaker?
Swagatam says
wish you the same
1)no need of a preamp if the input is from a source such as a cellphone, DVD player, TV, Ipod etc.
2) did you mean 16 ohms? never heard of 4 watt 1.6 ohms speaker, anyway both can be used here.
Mukesh Thakur says
Dear sir please help me to make an audio amplifier for my mobile…….i want to make this because i want to increase my knowledge about amplifier….
..
Please enlist the components and homemade diagram of simple audio amplifire
Thanks & Regards
Mukesh Kumar
Swagatam says
The design shown in the above article is the simplest and the best, you can try it.
Mukesh Thakur says
Dear friends i want to make an.audio amplifier at my home in.order to increase my knowledge about amplifier…..pls try to send a practically made amplifier diagram to my mail id mukeshthakur55@gmail.
Thanks & Regards
Mukesh Thakur
guru says
hey, thank u dude.
but that circuit is four small speakers and for head phones.
i have 4 50w speakers. could u pls guide me to make cheap stereo amplifier??
Swagatam says
OK dude, then probably you will have to go for this circuit:
https://homemade-circuits.com/2012/04/how-to-make-simplest-100-watt-mosfet.html
741, 324 etc won't help much….
guru says
hello friend..
i have a 12v 1Amp transformer and few lm324 and 1c 741 with me. i would like to do a audio amplifier of my can u help me with a circuit using above components.
thanking u in advance
Swagatam says
Only with opamps you won't be able to make an amplifier, you will have to add output transistors also for it.
You may refer the first circuit in the following link:
https://homemade-circuits.com/2011/12/how-to-build-electronic-spy-bug-circuit.html
Anonymous says
Is it possible to use an TEA2025B ic?
Swagatam says
It will provide only 2 watt output
naval singh says
hello sir,
my name is naval singh, and i want to assemble a high quality and high power amplifier for my room, that can give crisp and super clear audio quality(high bass and treble), please suggest me any circuit diagram.
i will be greatly thankful to you.
Swagatam says
Hello Naval,
You may try the circuit shown in the following link, I have tested it it's wonderful.
http://www.eeweb.com/project/circuit_projects/300-watt-mosfet-real-hi-fi-power-amplifier
naval singh says
thank u very much sir. and sorry for the late reply as my exams were going on.
Swagatam says
you are welcome!
neil says
also i can we increase the channel separation.. Is there any circuits for that.. Please help
neil says
hai.. Again..
I still didnt find any coaxial circuit or pcb ..
neil says
i need help..
I bought a sony dvd player .. It has only coaxial output for 5.1audio.. I asked in shop they told to buy amplifier for 5000rs but i already own a home theatre.. I need any assembled pcb or circuit to convert coaxial to analogue.. Please .. Reply
Emmanuel Chimwezi says
This is great
Emmanuel Chimwezi says
Hie there
these have really been a help, am looking forward to assembling my own amplifier and i hope the information provided here will be of great. help thanks
neil says
Hai sir .. I am very much interested in assembling circuits but my friends telling it is not possible .. Is it possible for beginners to assemble there circuits.. What will be the average cost?
neil says
Thank you sir ..
I have done course in mobile service and 5.1 hometheatre assembling is that enough basics. Can i have your mail or facebook id for asking doubts,. Please
harish says
Yes i gone through the link and made the circuit. But i think the sound is low when connected to a 9v battery. Can you publish the circuit which gives more sound and good quality of sound with this ic TDA2003.
harish says
if the article is published please inform me. I will be thankful to you.
harish says
thank you very much.
harish says
sorry for the late reply.i bought the IC tda2003.hope you would make the circuit quickly.
with regards.
harish says
thank you for your fast reply. none of these ic's are available in electronic shops.IC ul2003 is available in our area.i'll try to find this ic 810 or tda2003 in tv and amplifiers shop.
regards.
harish says
no reply from you
harish says
hello sir i am glad to meet you here. i have been redirected here from bright hub.i appreciate you for the special circuit request.coming to my problem, i am studying in a college far from my home. it takes 2 hours to go to college by college bus and again 2 hours to come to home.i am feeling bored of traveling. in the bus we wanted to listen music. but volume from the cell phone is not audible to everyone. so i made a amplifier circuit using ic lm386.but the sound clarity and the volume is low.it is producing some other sounds. i want a circuit which gives more volume better clarity and works at 12v or below. i read about the ic tda 1521, but they are not available in our area. so kindly send me a circuit which consists of regular ic's. or even by using transistors which works at 12v or below. thank you