The aim of the project was to make an audio amplifier that can deliver up to 10W R.M.S. power output. input can be given via computer/mp3 player or a mic (mic circuit explanation at the end). there are many different types of amplifiers tda2003 is probably a class b amplifier because its power consumption is quiet low then normal amplifiers and also that its noise is very low.
the purpose for which i chose this ic is that it has very less external components, very low distortion,very low input power and a corresponding high output power.

                          TDA2003 is a 10W car radio audio amplifier The device provides a high output current capability (up to 3.5A) very low harmonic and cross-over distortion. Completely safe operation is guaranteed due to protection against DC and AC short circuit between all pins and ground,thermal over-range,load dump voltage surge up to 40V

Step 1: Things Required

lists of components required to build the circuit


  • R1:220 Ω
  • R2: 2.2Ω
  • R3: 1Ω 1 watt
  • Rx: 39Ω                                  See the datasheet paw to alter the value of Rx
  • RV1: 10kΩ


  • C1: 2.2µF 25V electrolytic
  • C2:470µF 35V electrolytic
  • C3:0.1µF polyester or ceramic
  • C4:1000µF/35 V electrolytic
  • C5: 100nF polyester or ceramic
  • C6: 100µF 35v electrolytic
  • Cx 39nF                                       See the datasheet paw to alter the value of Cx


  • IC1: TDA2003
         :  connectors (cream shell connectors )
3-  2 pin connectors

Step 2: Helpful Material

Here is some helping material :
1- the data sheet of tda2003
2- the schematics of amplifier
3- and the PCB layout of amplifier

these circuits are modified ones the one i fabricated was a bit different .the difference was in placing the components not any thing else. if someone wants . datasheet open with any .PDF reader while the schematics and layout can be opened by Proteus (software) 7.0 or above.

Step 3: Circuit Diagrams

lets get started with the circuit the input form a computer or any other audio device will be given at the connector named as "input". u can even directly solder them if u want but connectors are easy to handle as they can be disconnected and reconnected without soldering and De-soldering except for the first time.

then the signal passes to the potentiometer named as RV1 it is just to control the input voltage and can be used as a volume control. c1 is a coupling capacitor and is used to block the dc portion present in the input signal.

c2 is present to reduce the distortion in the output as it is acting like a bypass capacitor (but u can see that there is 1ohm resistor except the ground so it is not actually the bypass cap.

c3 is there to reduce the ripple in the power supply and no other purpose similarly c6.

c4 is an output coupling capacitor . (i don't know the reason why it is there because it is reducing the BASS of the circuit never tried to reduce it if someone tries do tell me what happened).

we all know that there is a magnet and a coil in a speaker therefore they are inductive and inductors do not allow ac to pass through them that effectively so it is there to reduce the inductive effect of the speaker.

cx is present to reduce the higher frequency at the output terminal and also provide a feedback path to the amplifier.

                                    Connect a power supply 8-18V i recommend that u connect 16 V at least to get nice sound even when the volume is at its max u can purchase a power supply from the market OR u can use this link to make one for yourself
just replace the R2 and R22 resistors to 3k each to get +-16V (it was supplying +-12V)

at the output u can connect 2ohm/4ohm/8ohm Load to get 10W/8W/6W power respectively

Step 4: Demonstration Video & Modifications

here is a demonstration video :
don"t rely on this because the normal microphone of the mobile can not receive the bass so it seems that it has no bass but actually its base is awesome and also the video has distortion but actually the distortion is very low (zero below 50% volume) and negligible at 80% because the power supply is 12V if it was 16 or 18V then the distortion would be even less at high volumes .

another video

in case if someone wants to modify the circuit i.e.
increase/decrease bandwidth
increase BASS/treble
reduce noise
increase/decrease gain
the diagram shows how will the change in components affect these values

if u have any problem u can comment or mail me at dinitrogenoxide@ymail.com
and rate it if u like it :)

Step 5: Mic Attachment (Optional)

Here is a modification if u want to amplify your sound that u speak connect a microphone
u will need
a microphone
a battery
a capacitor 1uF (try to use a non polarized capacitor)
a resistor 2.1k

and a connector to connect it to the input or u may simply solder it to the input of the amplifier
NOTE make sure that u connect the ground of the amplifier to the ground of the mic (to ensure common ground) otherwise it may not work properly
Found errors
<p>Feel free to correct them :)</p>
<p>thanks for the very quick reply.</p><p>i dont have any 12v battery so i cant test it but i can either do it with 9v battery.</p><p>otherwise i like to build a amplifier using a premade module that i can buy from ebay to my pc.bcos these amps wont a another powersupply. so i can make a usb powered amp using premade amp.</p>
<p>You can test it with a 9v battery too. or simply test with any car battery that is normally 12V. With 9V battery if you increase the volume the distortion will occur..<br>You can get pre-build amps but they are not fun as I like to build my own stuff. USB power amps will never give you more than 5W output ideally.. it will be always less than 5W. </p>
I wont more than 5w for my pc. 3w is enough so i can use that. Otherwose its stereo and simple and easy. Although there are some 10w amps too. Like PAM8410. How ever thanks for your helps. <br>Because of my school i have not much time on my hobby electronics. But i will make the pcb for this amp soon. <br>But i cant desolder my ic its stuck i think i removed every other things but ic is not removble my thumb was wounded when i was desoldering that. Lol
<p>Do make sure that you dont draw more power than 5W form a USB port otherwise the USB controller will be damaged. Maybe that is the problem. You never solder IC directly on the board, always use an IC bed. Like you can see in the image I didnt have an IC bed so I used normal connectors. because when you are directly soldering IC in the board you might damage the IC with the heat from the soldering Iron. Another plus point is in case If your IC gets damage you can just pull the old one out and insert a new one without soldering or anything.</p>
<p>but i was soldered ic with heatsink is connected.otherwise i will buy more tda 2003 so can throw my old one.however i will use usb adapter to first test then ill use with my pc and how i measure power i dont have a multimeter.P=VI gives the power but its not practical as well.this is my usb amp you can give me a word about that, http://www.ebay.com/itm/PAM8403-5V-2-Channel-USB-Power-Audio-Amplifier-Module-Board-3Wx2-Volume-Control-/262130705142?hash=item3d083522f6:g:FAkAAOSwo0JWPHrG</p>
<p>Any USB powered amplifier can never have more power than 5W. Therfore they claim it to be 3W x2 but it will not be. secondly if you try to draw more power the controller shuts the supply to the usb Port or it can damage the port itself. Its your decision that do you want to buy a 5W amp or make a 10W one. One more thing you can buy ready made usb-powered speakers (In case you just want something to play on).</p>
<p>thats the problem bro my name. alright can u say me your name in facebook if exsist?because you are a good person that know about electronic technology.im glad to meet you.</p>
<p>I stopped using facebook a long time ago. You can ask me anything here, Message me in my inbox I will try to reply if i could help :)</p>
<p>hello</p><p>yeah yeah you are right. But the ic is heat up just like 50C degrees. I don't have any more ICS so I can't replace I saw that u used the schematics on data sheet. So I will make my pcb again using datasheets pcb. </p><p>Any ways how to stop the noise in this amp? I thought its my PSU maybe it will stop if I use a filter cap like 2200micro farad cap? Also I madea simple amp with a lm386. I was tested and it worked nicely just negligible noise and distortion in the higher volumes. But after 2hours it was crashed I mean that amp was too noisy and sound was Barely distorted even at volume 1. I can't fix the bug I used the same PSU that before distort and after distort that is the PSU that I also used in your amp. I think the problem might be in the lm386 ic. </p><p>Ilike to know your what are thinking about that. </p><p>Thanks by the way for your help in this case I'll tell you if my amp is worked. I think that will work. </p>
<p>50 degrees is not that bad. Normally when the IC malfunctions the temperature is so hot that it burns your fingers when you touch it. I didn't quite understand what you told about lm386. correct me If I am wrong. lm386 is a very small amplifier basically your cellphone has more volume than lm386 amplifier, so I am not a big fan. Do you have a battery? 12V DC battery try that. Any power supply that you use has a noise that is added to the amplifier (50Hz noise). If there is no noise with 12V battery than that is the issue. Otherwise the capacitor pins check their soldering.</p>
I saying that when im connect speaker directly to the input, its power(loudness) is more than output of amp! <br>So its just a useless one. Althougt i thoght once that amp wants more power but im using 2A power supply so i think its immpossibe. <br>And you are correct there some dry solder joints but i thought they connected nicely. I havent bread board so i cant test it so i have to remove all components and make it again. Somehow my circuit has a problem. Bcs 2. 2u cap's pcb trace was vanished. So now im jointing input with 1st pin using a wire. Its a bypass now(the2. 2u cap). <br>And also its just works when 1st pin and 2nd pin of ic is shorting! And sound isnt amlified. <br>Also reply to this.
<p>Hello again, Have you felt the IC does it heat up when u are using it, check carefully. and If possible try replacing the IC if the circuit still does the same than it is probably the circuit that is faulty. The amp definitely amplifies you can check it from the video link I gave above and worked for a lot of people. </p><p>It is the same circuit that is given in the data sheet so that pretty much means it should work for you too..</p>
Sorry about account. Im the guy that named pansilu and kasun. Sorry about that.
<p>This amp isnt works as an amplifier.sound is not amplified well.it is not works some times and also there is so unwanted sound either i cant increase volume.please help me to fix this problem.and can you say your name in facebook? then i can add u as friend thus i can solve my problems in this amp.please help me in this problem please.<br>schematics i used that are posted by you and i was modified them to add pc board terminals and for real TDA2003 ic.i made the board according to your layout files.</p><p>and i can see that your pcb is not like the pcb that u posted.anyways please help me quickly in this problem.</p>
<p>Correct me If I am wrong, Are you trying to say that sometimes it works and sometimes it doesn't ? If that is the case it means that your soldering is not proper and some of the joints are lose. make sure everything is properly intact. <br>Secondly it happened to me once that while soldering I kind of damaged the IC (Due to the heat from the soldering iron) when I replaced the IC it worked perfectly, as you can see afterwards in the final circuit I used an IC bed for inserting the IC just because I don't damage it again. plus IC bed is very convenient as if my IC gets damaged due to any other reason i can just replace it without soldering. I am currently unable to open my layout files, but the one I used is the same, I Just rearranged some of the components in the layout the connections however are the same.<br>Thirdly I didn't have the required resistance in the market so I used a parallel combination to achieve the results. make sure your RX, CX, R1 and R2 values are close to the one suggested. you can tune these values if there is any distortion in you amplifier (as IC's are not perfect in most countries).</p>
<p><a href="https://www.instructables.com/member/PansiluJ" rel="nofollow">PansiluJ</a> its me</p>
<p>This is one of the best amplifiers that i ever saw.thanks for posting this :).</p><p>but i have a question can i connect a tone control circuit to this.if can,then how i connect that? i mean where i connect that?<strong> to the</strong> <strong>input of this amplifier</strong>(before amplify the input signal) or <strong>to the output</strong>(after amplify the signal)?</p><p>i will use a 741 based tone control circuit.(<em>In a another instructable)</em></p>
<p>Thank you :)<br>Yes, you can connect a tone control with it.. In-fact with any amplifier.<br>Tone Controllers (aka pre-Amps) are always applied at the input, as it is easier to handle signals with low amplitudes. The pre-Amplifiers voltage/Current ratings are very low, even If you find a Tone Controller for more power it will cost you way too much. Plus Tone controllers normally use filters due to which the signal strength decreases drastically so its used before the main amplifier. So to sum it up, you can use a tone control at the input of any amplifier. <br>I have another Instructable that uses a tone control you can either use the pre-Amp I used in the link or any other. On How to connect the two see the link below</p><p>https://www.instructables.com/id/32W-Stereo-Audio-Amplifier/</p>
<p>Hello, I made this with my own pcb design according to your schematics, <br>with EAGLE. I soldered everything right and supplied 12V from an ATX <br>PSU. Nothing happened even though I input sound from a mp3 player. But <br>when I turned the variable res, the 'Rx' resistor (39Ohm) began to smoke<br> and burned out. The IC was heated a little bit (I think it was usual). <br>Then I replaced the Rx with a 33Ohm as I didn't have more 39Ohm. But it <br>stayed perfectly without heating or smoking. Still it doesn't work. But <br>when I touch the input wires, it outputs a big 'DRRRRRRRRR' sound. What <br>should I do? I used a mp3player, mobile phone, laptop to input and test <br>it. same result...</p>
<p>i saw your comment i may be late but here is the thing: your amplifier is bad i made one like this from another web site and it worked fine i put a 12 v, 2 amp adaptator there is a distortion because i used 2 amps power supplies but never the less it worked</p>
<p>The issue is with supplies... try using a battery and there WONT b any distortion.. power supplies convert AC to DC and yet there is a little AC component left no mattter how many capacitors you use ... that is why there is distortion.. in high quality supplies it will be less but will be still there .. as you can hear it in the video link too.. but after that i used a lead acid battery and it worked like a charm.</p>
<p>thats not it the iC can draw up to 3.5A right ? and you said use 12v 1 A <br>your adapter will get hot and the IC will not work att full power </p>
<p>&quot;can draw up to 3.5&quot; is only in an extreme case. The IDEAL supply ratings should be voltage = 8 - 18V and the current = 3.5A.</p><p>BUT always remember the IC will Never give you more than 12W output so whats the point of using a 3.5A supply? plus the whole point of this instructable is to make an amplifier, power supply is upto you people.<br>I personally didnt wanted to buy a new power supply so used the one that i made already.</p>
<p>but what if they made it with 1A and the sound was bad they will not know why and they will blame you and the tda2003 to prevent that you should say prefer 2A-3.5A power suplies</p><p>just saying for your own good</p>
<p>Hi, I had this issue once. kindly check your volume control POT , C1 and ground . if any of these is faulty you wont be able to hear anything. as far as the the resistor issue is concerend its value is 39Ohm not 390Ohm so use 39 ohm resistor or anything close to 39.. What I suspect from the &quot;DRRR&quot; sound the issue is with your ground terminal it does not connect the IC's ground to Mp3 players ground ..</p>
<p>is this IC i dont think a simple pot will do the trick i tryed in on my own before coming here and it didnt work you need some thing like this</p>
thanks for your quick reply...<br>I found that I had soldered c1 reversed polarity. I corrected it. But the issue is same. Also I could realize that the 220ohm res was getting too hot. The pot works fine... How could I check the ground as you told above? Is my pcb the error? Or maybe the IC had blown out? <br>When I first turn the circuit on and touch the input wire with my hand, I hear the drrrrrrr sound. But after a few time, It also didn't work.... The issue is same...
<p>No problem, see this image the GND terminals marked as &quot;red Circles&quot; make sure they are connected to the -ive terminal of the battery/supply (in short do a continuity test for all the GND but make sure u do it on the marked ones because they are must) even if this doesn't work try shorting the pins marked 2 and 3 of the potentiometer. marked in &quot;blue circle&quot;. Its pretty normal for these IC's to blow up so make sure u don't solder it to the board instead use a connector like I did so that whenever it blows up just replace a new one. plus some people do mess up while they are soldering the IC to the board. one more thing use a heat sink with the IC too. its better.</p>
<p>Thanks for ur reply, but I could not get it to work. Can you pls send me the ready to etch pcb file (as an image in order to use toner transfer method), because I do not have proteus to open that file u have provided above. Maybe my pcb design is wrong... I'll give ur pcb design a try... Thanks</p>
<p>First here is the link to proteus: </p><p><a href="http://www.labcenter.com/download/prodemo_download.cfm" rel="nofollow">http://www.labcenter.com/download/prodemo_download...</a><br>its very easy as compared to any other simulator/PCB designer. It has a trial period so you dont have to buy it for some time and there are cracks available (which i dont support).<br>Second here are the files as per your request </p>
<p>hi , if i connect a mic as a input to this amplifier and connecting a speaker to this amplifier as an output , can i hear my voice from that speaker ...!? </p>
yea, you will. It will be just like a loudspeaker :)
<p>can i use the mic circuit with tda2050 amp ...</p>
<p>Hi Abbas yes you can use it with any amplifier its totally generic.</p>
<p>can i add bluetooth to it.?</p>
<p>Hi Kavish laxkar, yes you can add a bluetooth to it.</p>
<p>how and wat colud be the circuit.?</p>
<p>just google an audio bluetooth receiver .. here is how u can disasseble one .. </p><p><a href="https://www.instructables.com/id/STREAM-MUSIC-VIA-Bluetooth-on-any-amplifiers/" rel="nofollow">https://www.instructables.com/id/STREAM-MUSIC-VIA-B...</a><br>the place where he connected the audio pin can be connected to the audio input of the amplifier and there you go :) wireless portable amp :) </p>
<p>i have hc-05...can it br used.?</p>
<p>I googled it and most of the people say that it is used for serial communication and audio stream conversion is not included in it </p><p><a href="https://www.instructables.com/answers/Can-an-HC-05-Bluetooth-module-be-used-as-an-audio-/" rel="nofollow">https://www.instructables.com/answers/Can-an-HC-05-...</a><br>however if u use arduino and do the serialization urself (which wil cost u more than a new bluetooth that supports audio) it can be done.</p>
<p>Hi, I have made this project but have a question.When I plug my amplifier with music I can hear some scratching noise.Could that be from Cx which I put 33nf instead of 39nf? Thank you for interesting design and helping with my first breadboard project.</p>
<p>Happened to me at the start .. there can be three possible reasons for this .. </p><p>1- <br> Either the audio input is not connected to anything .. i.e. its <br>floating .. possibly touching the floor it could cause this problem. <br>(using a battery should solve this problem but still make sure that the <br>circuit's ground is not directly in contact with the floor)</p><p>2- Either the connections are loose in ur PCB/Bread-board.<br>3- kindly check that ur power supply does not have any noise too (use a filter if yes).</p>
<p>Good day sir, congrats for your project, it's something easy, powerfull and very elastic! buuutt, it was working for me ,but then, yesterday, i just attached it to the power supply (atx power supply, 12v, and also tried with 17v and worked really well!) but when i attached it, my tda 2003 started to ''smoke'' i thought it was the C4, but when i attached again, nothing happened, and it was working fine,so i thought that some wire where touching something... i hot glued almost everything that could touch something, and worked well, i just attached it again and while working the tda started to smoke and i saw a bit of fire also :O now ,when i attach the power supply it work for some second ... what do you think about it? why my TDA started to burn? too much Ma maybe? :O or just i may need some heatsink? </p>
<p>Good day to you too .. and thanks, m glad u liked it :) </p><p>I need to be clear on some things before i can give u a right guess.<br>you were using the same supply before but yesterday it caught fire right ? </p><p>and Is there an Ampere knob on your power supply ?</p><p>plus you should definitely use a heat sink with TDA Ic's its recommended for long life of the IC .. </p>
<p>Hi sir, thank you! you're so kind :) anyway, i use a commond atx power supply, so i can have 12v with 16a, and 17v with maybe 13a or so around. but i was just thinking that amperes aren't a problem since the ic's use how many amperes he need, not more! so, i just wired a diode to see if it's a polarity problem since my tda caught on fire at the vcc pin.... i don't think it's a heatsink problem, anyway, i'm using it too, i just bought a tda2030 too, so i want to try it, what do you think about it? :) also, i bought 10 tda2003 for just 1 euro from hong kong, so i can replace it when i need! :D thank you sir, see you:)</p>
<p>Actually in voltage supplies the amperes are not a problem but in supplies that are voltage and current both they have problems ... because the amplifier suddenly draws a lot of current when a high beat is being played so the power supply switches it self to current supply and if the current supply is set to a greater value than the max current which is 3A it will burn the IC. i have not tried TDA2030 instead i have tried here is the link </p><p><a href="https://www.instructables.com/id/32W-Stereo-Audio-Amplifier/" rel="nofollow">https://www.instructables.com/id/32W-Stereo-Audio-A...</a></p><p>and no problem :) see you..</p>
<p>If I can add something, When you have a Bigger Heatsink you can get about triple Amperage on the circuit, but try to stay low on it.</p>
<p>Havent tried it. but seems logical.</p>

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