2 x 60 W audio amplifier circuit

jacky July 1, 2010 46 Comments

Description.

The circuit diagram shown here is of a 2 x 60 Watt stereo amplifier based on the LM4780 from National Semiconductors. LM4780 is a superb audio amplifier IC capable of delivering 60W Rms power output / channel into 8 ohm speakers. The LM4780 has very low total harmonic distortion (less than 0.5% at full output) and has a power supply rejection ration (PSRR) of 85 dB. The IC requires very few external components and has a built in mute facility. The LM4780 is completely protected using their trademark SPiKe technology and has a signal to noise ratio greater than 97dB. The circuit given here is well suitable for applications like components stereos, self powered speakers, home theatre systems, compact stereos etc.

Circuit diagram.

2X60 watt amplifier using LM4780

LM4780 pin configuration

LM4780 pin configuration

Notes.

  • The circuit must be assembled on a good quality PCB.
  • The amplifier can be powered using a 35V DC dual supply.
  • K1 and K2 must be 8 ohm, 60W speakers.
  • An adequately sized heat sink must be fitted to the IC.

Comments
  • TJ
    March 18, 2015

    Can you make full instructions and send to me i’m confused on the pins for the lm4780, switch with the 10 ohm resistor and the inputs A and B. How could i use a pententiometer to make a volume switch and could i use an audio jack female for the inputs?
    Thanks

  • Vivek verma
    March 16, 2014

    Sir,i’hv just made the circuit but sound is not clear and IC become very hot when it is in use. Can you help me,where i’m wrong

  • Vivek verma
    March 16, 2014

    Sir i’hv just made the circuit but sound is not clear and IC become very hot when it is in use. Can you help me,where i’m wrong

  • Vivek verma
    March 16, 2014

    Sir, can we use laptop stereo output for this amplifier circuit with out using preamplifier circuit…?

  • bert
    February 27, 2014

    i like to assemble this 60 watts IC audio amplifier. will you please send me the schematic and block diagram. i appreciate so much if you can. thank you.

  • sarath
    August 19, 2013

    will you please post the ckt diagram with the IC leg numbers.
    reg:)

  • prakash
    February 9, 2013

    i have a doubt that t/f 0v should connect to the ground of amplifier circuit or no connection?im using 24-0-24 2amp t/f.i want to know the heat sink size of LM3886.
    thanking sir.

    • seetharaman
      August 23, 2013

      Hi Prakash connect 0 of trafo to common (shown as ground)of the amplifier. The heat sink should be a minimum 2mm thick 20cms by 10cms aluminum. for this size if you use an extruded alloy heat sink with fins will be the best.

  • SOUMEN
    January 14, 2013

    hi, I have a SONODYNE MODEL NO SC-3070 amplifier.but have not speaker.please send it to me how many watt @ohms speaker.

  • Jamal
    November 1, 2012

    Can you make the layout design for this? If you can send it to me… here is my mail simple.deejay@yahoo.com

  • Jamal
    November 1, 2012

    Sir i have 1 question…can i use a TDA7377 instant the lm4780?

    here is my mail simple.deejay@yahoo.com i’m waiting for your mail…

    PS. Thank You!

  • Jarez
    May 29, 2012

    Is the output of this amplifier full range? also would it be possible to separate the output into a Low/Mid and High?
    Kind Regards

  • November 6, 2011

    THIS CIRCUIT IS SO CHEEEEEP!!!!!!!!!! I CANNOT WASTE MY MONEY TO MAKE THIS LM4780 AMPLIFIER

  • seetharaman
    August 21, 2011

    Hi Devendra try TDA2050 will give you 50watts power with very low distortion. you can use two as push pull amplifier similar to TDA2030 but with lesser distortion figures.

  • Devendra
    August 21, 2011

    Sir, lm4780 op-amp is not available in allahabad. Can you tell me some simmilar i.c.s for stereo amplifier.
    Thanks

  • seetharaman
    August 9, 2011

    Hi Shubham our passive tone control unit has got all required controls for a stereo system (one for each channel that is two of each controls). kindly go through the article.

  • Shubham
    August 8, 2011

    Sir, as you said to place volume and tone controle before inputs a & b using preamplifier,but as this is stereo amplifier hence two preamplifiers must be used and this will cause pair of volume and tones control 1 for each channel. Which is not practical. Tell me sir what to do.
    Probabily i didn’t understand what u said in previous post.

  • Shubham
    August 8, 2011

    Sir, what is preamplifier?
    Thanks a lot

  • seetharaman
    August 7, 2011

    Hi Shubham LM4780 is a dual channel high power operational amplifier (with inverting and non inverting inputs similar to an operational amplifier). Input A & B should be connected through volume control. A pre-amplifier has to be used before this mail amplifier. Use the passive tone control appeared earlier which has got volume, bass treble controls.
    http://www.circuitstoday.com/passive-tone-control-circuit

  • Shubham
    August 6, 2011

    What is name of operational amplifier used, and what is lm4780. Please explain i am confused.
    Thank u

  • Shubham
    August 6, 2011

    I want to know that where i can place volume controle for speaker?
    Thanks

  • seetharaman
    July 6, 2011

    Hi Rohit This willbe suited for simple stereo system with only two front full range speakers of 60 watts capacity. for side and rear speakers you require amplifiers around 10watts capacity each.

  • Rohit Kumar
    July 5, 2011

    Hello Seetharaman,

    Can we add more speakers such as front (left & right) rear (left and right) speakers to this circuit.

    thanks

  • Seetharaman
    May 28, 2011

    Hi John
    the PCB art work for dual side PCB is available on National Site. artwork to given to PCB manufacturer for requirement. not readily available in the market. visit following site.
    http://www.national.com/ds/LM/LM4780.pdf

  • john cruz
    May 27, 2011

    wher can i find pcb of this?

  • Donc
    May 15, 2011

    Pls guy i’m new is this circiut tested and confirmed pls i need reply

  • Seetharaman
    November 18, 2010

    Hi Pattrick you can use 10K potentiometer as volume conrol just before the input to IC pin no 16 and 21 of the IC input A & B.
    you can also refer to National semiconductor application data.

  • patrick vaz
    November 18, 2010

    Hi Seetharaman,
    Can you introduce a potentiometer as volume control for the above circuit.

  • patrick vaz
    November 8, 2010

    Hi Seetharaman,
    what is the budgetary cost of this project, excluding the power supply.

  • Seetharaman
    November 8, 2010

    Hi Patrick Kindly refer to the 23rd page of national application for PCB layout
    http://www.national.com/ds/LM/LM4780.pdf

  • patrick vaz
    November 7, 2010

    Hi seetharaman,
    Any PCb schematics available for this wonderful circuit,
    thanks

  • seetharaman
    July 27, 2010

    Hi Adnan it will remain the same

  • adnan
    July 27, 2010

    you suggest me 27 – 0 – 27 transformer @ 2.25Amps for 2 x 60watts but will it required more current on bridged configuration or the transformer ratings will remain same?

  • seetharaman
    July 26, 2010

    Yes Adnan you can get 120watts in bridged mode
    you please go through national application
    http://www.national.com/ds/LM/LM4780.pdf

  • adnan
    July 26, 2010

    can we get 120 watts mono from lm4780?????????

  • seetharaman
    July 25, 2010

    Hi David I am yet to try, ordered and waitng for the chip at chennai. I love STK465 that is discontinued but a great chip by sanyo, kicking for the last 17years at home.

  • david
    July 25, 2010

    Hi seetharaman

    Did you try this amplifier

    it is working or not ?

  • Sanjay
    July 7, 2010

    IC pin configuration Name and Diagram Pin Name r No match?
    plz Chk VoA or VoB is Speaker out and Hi Name Is not for IC?

  • Sanjay
    July 7, 2010

    Hi, when u try this diagram?
    its really working Amplifier?

  • RUCHIT
    July 5, 2010

    well diagram!!!

  • seetharaman
    July 5, 2010

    Hi Adnan I have o get the IC and ICL7107 0-200mV panel meter. give me few days time

  • adnan
    July 4, 2010

    when you try this then tell me then i will try too

  • oriola taiwo afeez
    July 3, 2010

    please i need an isolator that can work for an uninterrupted changeover switch

  • seetharaman
    July 3, 2010

    Hi Adnan I am yet to try.
    You require a 27 – 0 – 27 transformer @ 2.25Amps rating for stereo amp.

  • adnan
    July 2, 2010

    is the 32-0-32 volts 4 amp transformer is suitable for this??????
    if not then suggest the power supply???

  • adnan
    July 2, 2010

    do you checked this amplifier in Ur lab????

Leave a Reply to david Cancel reply

Your email address will not be published. Required fields are marked *