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  • This is a compact, easy to build amplifier that uses one IC only but delivers 40 watts of audio power. It is ideal for amplifying audio from your mobile CD player or iPod. The chip being used here is the TDA1514 originally brought to the market by Phillips/Valvo. The best characteristics of this chip is its high output power and robustness. It is available in a 9-pin SIL plastic package with a metal mount.

    Its package has a heat resistance of less than 1.5K/W. This means that the heatsink must have a heat resistance of only 3.8K/W when the chip reaches its maximum power dissipation of 19W (at Ub = +/-27.5V, Tu = 500C).

    One can see from the diagram that only a handful of passive elements are needed to build the chip into a powerful audio amplifier. The power supply as supplied must be able to deliver a current of at least 3 amperes. The standby current consumption is about 60 mA. The supply voltage must never go beyond 27.5 volts!

    In building the circuit, keep the wires to the power supply and outputs as short as possible. The resistos R4 and R5 set the voltage gain at the feedback which, in this case, is between 20 and 46 dB.
    For a single channel amplifier(mono), a 80 VA transformer (T1) should be sufficient. If you construct two channels (or stereo) amps, 120 VA is recommended. Capacitors Cx and Cy should be at least 4.700uF rated at 35V. It can be up to 10.000uF.

    Capacitors twice as large discharge slower giving better peak power potential resulting to better power output. Feel free to increase the capacitance but take note that you may not get much additional benefit for the price involved. Make sure they are connected the right way around too or they will blow and cause injury.

    1 chip 40 W audio amplifier circuit diagram

    TDA1514 40w audio amplifier schematic

    A 0.25 mA fuse (F1) should be installed. If using toroidal transformer, the fuse must be a time delay (slow blow) variant. Be sure to correctly earth the supply and any metal casing around it. The components on the earth and ground connections (Dx, Dy, Rx, Cz) form a loop breaker. This is recommended because it can eliminate those troublesome earth loops. Rx is a 5 W or better wirewound resistor. The Cz capacitor must be rated for 250 V AC.

    Do NOT use a 250 V DC capacitor for Cz as it would fail if there ever was a fault causing mains current to flow to earth. Dx and Dy are rated at 250 V/ 1 A. If your local rules and regulations prohibit constructing this, omit all these components and connect the earth to ground but NEVER disconnect the earth lead… it could save your life or somebody elses!

    Power supply for the 40 W single chip amplifier

    power supply 1 chip amplifier

    Constructing the power supply for this amplifier is simple. As shown on the schematic above you need to wire up a 18-0-18 (center tapped) transformer in order to get the recommended +/- 25V. Be very careful since this construction involves mains wiring.


    Printed Circuit Layout for mono 40 W amplifier


    Parts Placement Layout for mono 40 W amplifier


    Printed Circuit Layout for stereo 2×40 W amplifier


    Parts Placement Layout for stereo 2×40 W amplifier


    ask a question

    26 Responses to "TDA1514 40 Watt Audio Amplifier Circuit"

    1. hi thanks alot for giving us a sample of your circuit.Its been a great aid for me to finish my experiment and my power amplifier for a short period of time.Thanks a lot and very much.! ^_^

      Your friend,

    2. i wan to design a audio amplifer for running my two 40 watt , 4 ohms speakers but with my lap which has only one jeck for input signal.
      So in this case how 2 make arrangement for two input for stereos.
      so how to solve this….

    3. that is very useful to me

    4. very good sound with my 4 ohm 45 watt x 2(stereo) speakers

    5. hi could u plz send a full list of the components to my email at danger954@hotmail.co.uk plz and thank you

    6. Francis P says: on May 10, 2011 at 6:41 pm

      Hi, I was wandering if the power supply chip source could be a “sealed Lead Acid Battery 12V 7AH” as to make the whole circuit portable.

      Also if you can mail me a full parts list for both Amp + Power Supply.

      Your help is much appreciated.

      Francis P.

    7. i want 40watt amplifier circuit output voltage 100v

    8. i want 40 watt amplifier circuit output voltage 100v

    9. Hi, I was wandering if the power supply chip source could be a “sealed Lead Acid Battery 12V 7AH” as to make the whole circuit portable.Also if you can mail me a full parts list for both Amp + Power Supply.Your help is much appreciated.

    10. N.Muthukrishnan says: on August 25, 2012 at 6:29 am

      Hallow sir first thanks for this circuit,and pl give me a 24 volt dc operated power amplifier circuit for bus amplifier. thank you.

    11. give me information about projed

    12. i like it. But i want partlist of this amplifier,because i had a doubt in R3,R4,R6.is it ohm or kilo ohm? And how much watts each resistor.so please send me partlist.my mail id:darvinvarghese003@ovi.com

    13. High, will this work with a 4 ohm Speaker? If not is there any way of adapting the circuit?
      Many thanks.

    14. justin23 says: on June 25, 2013 at 4:47 am

      Hi, i have some doubt in R3,R4,R6.is it ohm or kilo ohm? And the watts rating for them. Do you mind sending the part list to me : justinboey23@gmail.com

    15. Nemanja says: on August 3, 2013 at 2:15 pm

      Hello , can i use this project to make self powered speakers(active monitors)?
      I don t know how to connect tweteers with it:(

    16. jhorapalok jhorapalok says: on August 12, 2013 at 12:06 am


      I have the same doubt as Justin23….R3,R4,R6, is it ohm or kilo ohm? And the watts rating for them?
      Please answer, i like to build the circuit.


    17. jhorapalok jhorapalok says: on August 16, 2013 at 12:16 am

      Dear sir,

      Can we add a volume control like this one in the following link with the above stereo 2×40 W amplifier?


      Looking forward to hearing from you eagerly.


    18. hello! Can u send me any calculation for this amp? mail: toni_lofe@abv.bg

    19. preet says: on May 9, 2014 at 7:42 pm

      can i use this on my car battery 0-12 dc help me plz sir or reply me on muy id dilpreetkala@yahoo.in

    20. Part list required

    21. Could you send me parts list please?

    22. Can I connect the aux output of mp3 player to the input of audio amplifier and work it with 12V DC supply?

    23. Nathani Abhay Amitkumar says: on October 2, 2015 at 8:21 am

      pls. mail me component list

      if yes so send me as fast as

      yours thankful
      Abhay AmitKumar Nathani

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