100 Watt sub woofer amplifier.

Description.
This is the circuit diagram of a fully transistorized sub woofer amplifier that can produce an output of 100W.There are seven transistors including four in the output stage. The transistors Q1 and Q2 form the preamplifier stage. Transistors Q4 to Q7 form the output stage. Since no ICs are used the circuit is very robust and can be easily assembled on a general purpose PCB.

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Circuit diagram with Parts list.
100-w-subwoofer-amplifier-circuit

Notes.

  • The circuit can be powered from a +35V/-35V, 5A dual power supply.
  • Use a 100W, 12 inch sub woofer at the output.
  • All electrolytic capacitors must be rated 100V.
  • The transistor Q4 to Q7 must be fitted with heat sinks.
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742 Responses to “100 Watt sub woofer amplifier.”

  • harith says:

    sir..i made this circuit…i designed the PCB and buld it…but it works in best way for 3 mins and then lower the sound and produce a humming sound with varying bass sound… one 3773 transister is heating up… i cant understand why it is happening… can any one help me….

  • anil babbar says:

    sir I want to add a filter circuit to this amplifier which requires a separate power supply of +12 / -12 VDC, can you give me a power supply circuit that can supply +/- 12 VDC and +/- 35 VDC from a single transformer
    thanks

  • Ateeq says:

    my question is that i can not get the transistor 2n3773 because in the circuit diagram you have shown three legs of that transistor but in market it has only two legs.could you please tell me the substitution of that transistor or please guide me because i have to submit my final project in two weeks. please help me……….

  • stj says:

    Hi sir, I have tda7294 sub woofer, witch is the best sound quality, tda 7294 or your 100 wat trans..?

  • Rateesh says:

    Hi I assempled this circuit 2years before even now better work with 10″sub

  • Riyaz says:

    Sir how can i convert 12 -0 -12 suly to 25-0-25 with a transistor power suply please give me diagram

  • john says:

    hi sir which is the best for subwoofer amp. this circuit or 150 watt amp circuit.???? i want to make subwoofer amp.

  • vinnie says:

    Hello sir,can i use 12v input to the amplifier? if yes pliiz provide the circuit containing 12v input signal.
    another request sir…please send me the dual 35+/35- power supply circuit of the amplifier.

  • john says:

    Hi sir! is this ckt need separate transformer? or can i use tip 142 and 147 150 watt ckt’s powersuply. if i connect like that, is this both amps output transistors will short?

  • Midhunmp says:

    Any problem when can i connect 10inch 4ohm subwoofr on this circut. If no problem how much power will get?

  • Midhunmp says:

    Can i use 25v 5amp ac to the circut?

    • Seetharaman says:

      Why this funny question? use supply voltage as recommended in the project. you can use a 25-0-25 5amps transformer with rectifiers smoothing capacitors and 6amp bridge rectifier (See 150 watts amplifier circuit for the power supply circuit). which will give you +35 -0- -35 volt DC for the amplifier.

  • Rituraz says:

    Hello, every one can i attach Q4 to Q7 in one heat sink and also give the perfect size of heat sink for this project thanks please reply I m waiting .

  • abubakar says:

    hello sir pls I have a question based on how to calculate the output power of this amp. U mention dat d relation of d output power is d square of voltage swing on d speaker leads divided by the impedence.pls sir I need explanations in detail. Thanks

  • Chris says:

    Hello,

    I managed to build the circuit and on an ossciloscope the readings look correct but when i connect a speaker instead it shorts on the negative end of the circuit. Any idea how to fix this? Any help would be greatly appreciated!

  • abubakar says:

    pls sir I made another circuit of dis same amp n I don’t want to use these 2n3773 due to insulation issue, pls sir can u tell me any 3 pin transistor Wich will b as good as d 2n3773 ? I tried using 2sc5200 but d sound isn’t as good as d 2n3773.
    n pls sir tell me d use of r1.tank u sir for ur time

  • guna says:

    sir
    want to be all all transistors please sent me i am all really getting transforms 35-0-35

  • abubakar says:

    thank u sir for d response my amp is working perfectly

  • lcd950 says:

    Does this circuit work?
    Did anyone make this circuit?

  • babu says:

    I have la4400 circuit what transformer it require for input power.
    please specify me that are there any connection wire for bass in la4440 and i will connect 2 woofer speakers as 80w with 8″,let me know if I am wrong that at first i need a transformer to connect to la4440,where to connect the volume,bass connection.
    here we have mac 8″ can i use.

    what type of woofer I must use name please.

    • babu says:

      or give me a name of circuit to connect 8″ to 12 ” woofer.

    • Seetharaman says:

      This IC is a car amplifier chip to handle car battery voltage . you can use 13.2 volt DC. A 0-9 volt transformer rated for 2 amps is more than sufficient. use a 3amp bridge rectifier and 4700uF 25 volt filter capacitor in parallel with 0.1uf 25volt ceramic disc capacitor. The IC will give 4.5 watt rms output into 4 ohms speaker.

  • jonsg says:

    Direkt auf. Es ist mehr informativ und leicht zu verstehen. Vielen Dank so eine schöne Leitlinie ……

    pa verstärker

    pa endstufe

    Mehrzonenendstufen

  • abubakar says:

    hi every 1 pls I have a question..pls I have a 2ohms 50watt subwoofer speaker can I use it wit dis amp

  • abubakar says:

    thank u sir seetharaman for d wonderful post n I thank u all for all ur comments. through d comments I was nw able to build my amp n it works really great. Thanks every 1 once again .i have nw started building d 150watt amp.sir may god reward u for all ur efforts

  • rohin says:

    hi, for pcb of this amp read my comment (rohin).

  • abubakar says:

    hi every one I have problem building dis circuit can someone help me out?pls

  • abubakar says:

    Pls can someone guide me on building dis circuit? I only have a humming sound @ d output.Whr must I have gone wrong?

  • harith says:

    sir please…im waiting for ur reply….pls any one….help….

  • alexander says:

    Hi i like this circuit,please give and send me a printed circuit board for this project.

  • Kannan says:

    how to noise produce to this ic

  • harith says:

    seetharaman sir,
    im an university student from Sri Lanka.im interested in this circuit….im going to build it.i have 28-0-28 transformer.can i use it? im going to use 4ohms 10inchs 200W subwoofer speaker.is there a chance to having a PCB desing of this cicuit..pls help…thanks.

  • saravanan says:

    please i want to know the full spare list and pcb layout

  • IH55T says:

    This amp works great. I was unable to find a 2N5494, but searching through the replies from the author identified similar replacements. The only problem I’m having is the presence of 0.177v at the output with no input. I’ll do a little adjusting on the bench to move the crossover point. Regardless, this works as published.

  • guna says:

    my mobil no 9843946968

  • guna says:

    want to all spears

  • krishna says:

    Hai sir, SEETHARAMAN. Does this amp needs preamplifier to amplify below 140htz signals or jst audio output any source will do, can u plz send me the circuit PCB,thanx for the reply.

  • guna says:

    seetharaman sir plase help with me my mail id gsgunasiva077@gmail.com

  • guna says:

    all spears data sheet and transister 3 how can test telme my mobil no 09843946968

  • guna says:

    please all spears list (35+)+(-35):70dc given onely for this project give me one sample assambled pdf or photo

  • Collins says:

    i need information on electronics

  • sravan says:

    how to add a volume controller to the circuit
    please please send me the circuit diagram to my email id please sir please,,,,,,,

  • RAVI says:

    CIRCUIT FOR 7.1 CHANNEL AUDIO. FOR 2 CHANNEL INPUT.
    ABOUT 300-400 WATT SUB WOOFER,& 50-100 WATT SPEAKERS.
    SIMPLE CIRCUIT FOR IT.
    PLEASE REPLY ME.

    • siva.R says:

      CIRCUIT FOR 7.1 CHANNEL AUDIO. FOR 2 CHANNEL INPUT.
      ABOUT 300-400 WATT SUB WOOFER,& 50-100 WATT SPEAKERS.
      SIMPLE CIRCUIT FOR IT.
      PLEASE REPLY ME.

  • Kwadwo Boateng says:

    Sir, after building the 100w subwoofer power amplifier how will it look like. Thanks

  • natarajan says:

    hello sir, i want 5.1 home theater circuit digram pleas

  • omer says:

    150 watts subwoofer amplifier circuit added here
    visit
    www . it-tronics . blogspot . com

  • Guna says:

    Transister how cane checked .? Bass callactor emater and npn pnpn

  • Guna says:

    Yoused for 35-0-35 volt transformer dc circuit diode and capacitor witche valvu yoused an this circuit

  • cooool says:

    hi sir I made this circuit on breadboard only speaker humming there is no output sir please help me sir my circuit is till on table

  • Guna says:

    100w amplifier connected load 8″ speaker how much sound came ? Input volt 35 -0-35vdc 5amps

  • Guna says:

    680 ohm how? watt

  • Guna says:

    47 k is how ? Watt

  • Guna says:

    100w amp traied this projact please help all capacitor valvu 100v reastor valvu some miss ing

  • Harry Cat says:

    I have a question about the required power supply for this amp circuit..
    I currently have a 36-0-36 5 amp per side transformer that will deliver +-35 volts DC after going through the 5 amp bridge rectifier. I also have one each per side 4700MFD 63 volt Electrolytic Cap and one 2.2MFD 60volt Poly Cap per side..
    Is this power supply setup too much for the circuit to handle or do I need to by a 25-0-25 transformer to keep from over loading the circuit?
    A 25-0-25 transformer that delivers 5 amps per side is extremely expensive..
    I could build my own transformer but getting the E I type silicon Iron sheets is impossible since I live in America. America doesn’t make anything or have anything to make a transformer except magnet wire only.
    Thanks

  • normal says:

    Hi sir I transistor 2n5294 and only 5294 are same? Please reply me

  • normal says:

    Hi sir I transistor 2n5254 and only 5294 are same? Please reply me

  • vitthal says:

    Hi Sir,
    please sir,
    Can you please send me a simple home theatre circuit using Subwoofer. with material list

  • Janaka says:

    Hi Sir,
    This one has no Filter circuit. Right.? So if we connect this to any input other than SUBWOOFER OUT PUT of a Hi FI set up we should have a filter circuit connected to this first. Right sir.?
    Forgive my Ignorance. How do I determine the BCE pins of Transistors. I know how to figure out BCE of C828 and D400 transistors but is it the same for these Transistors too.?. All Transistors have the BCE pins in the same way or are they different depending on PNP or NPN. Please explain..Sir..

    • Seetharaman says:

      Hi Janaka if you have a subwoofer output from your dvd player, can be connected directly to this amplifier. If you have only stereo information(left and right channel information) then you have connect through a sub woofer filter bothe channel information to make it as 2.1 information. 2 is left and right .1 is subwoofer signal.
      Transistor lead configuration will differ for each manufacturer, hence you have to consult their catalog. the following link is the best filter
      http://sound.westhost.com/project48.htm

  • ASHISH KUMAR says:

    HI,
    SIR,
    KINDLY SEND ME A CIRCUIT OF 200 WATT RMS SUB-WOOFER AMPLIFIER, ITS OPERATING CURRENT AND VOLTAGE, PART LIST AND PCB.

  • ajithsoman says:

    its working..well..

  • Janaka says:

    Sir, Forgive my Ignorance. How do I determine the BCE pins of Transistors. I know how to figure out BCE of C828 and D400 transistors but is it the same for these Transistors too.?. All Transistors have the BCE pins in the same way or are they different depending on PNP or NPN. Please explain..Sir..

  • Janaka says:

    Hi Sir,
    This one has no Filter circuit. Right.? So if we connect this to any input other than SUBWOOFER OUT PUT of a Hi FI set up we should have a filter circuit connected to this first. Right sir.?

  • SUBRATA KARMAKAR says:

    Can you please send me a simple 2.1 home theatre circuit using Subwoofer.

  • Bipro says:

    pleas give me the pcb of this circut.

  • LOGANATHAN G says:

    hi sir
    can you please give me the PCB layout of this circuit..

  • Janaka says:

    Please let me know this 100 watts are PMPO or RMS???

    • Seetharaman says:

      Hi Janaka it is 100Watts RMS power at <1% distortion into 4 ohms load with plus minus 32 volts DC and into 8 ohms load with plus minus 45volts DC supply.

  • rohin says:

    hi, for pcb of this beautiful amplifier visit at my blog http://www.123456789wertt.blogspot.in/

    • vicky says:

      thanks for pcb…did u check that ckt by giving connections>>>>?

      • rohin says:

        hi vicky, i made 6 amp on this pcb.pcb is working 100%.alternative list of transistor.bc 108 or bc 109 or bc 547 and 2n 6107 or a940 and 2n5296 or 2n 5294 or c2073.2n3773 or 2n3055 or c 5200 or mjl 21194.

    • Alfian says:

      Hi….. Rohin
      how to add volume control in this subwoofer…?

      • rohin says:

        hi, you can use any tone control circuit.for a subwoofer you need sub filter circuit otherwise you can add a tone to control volume that is your taste.

      • Seetharaman says:

        August 9, 2011 at 8:36 am
        Hi Shbham Use a 100k log potentio-meter(three tags), preferred but if not available use 100k lin (not rheostat- 2 tags only). connect center of the potentiometer to C1. one end of the potentiometer to common(ground). Connect input between both the end of the potentiometer such that input signal ref is connected to common and actual signal is connected to other end of the potentiometer.

  • Petar says:

    Hey there im a student at chisholm catholic college and am working on an engineering project.Just wondering if you have a diagram of a circuit for a 100 Watt sub woofer amplifier that can run off 12 volts.

  • Lonely Eagle .. says:

    Sir can i get your pcb lay-out !? So that i can build it at my own ..

  • RHOL says:

    sir, can i have the design of pcb layout…thanks!!!

  • Ch.shashank says:

    sir i want to design this ckt please if u have some time please send me your pcb layout sir please i want to try it for my project sir…….

  • safder says:

    hi sir
    can you please give me the PCB layout of this circuit..

  • abdul says:

    Sir i am used for 100 watts subwoofer . Which capacitor use?

  • srinivasan says:

    dear sir,

    i am using this amplifier for my sub-woofer with KFC W3013 ken wood 12″ Woofer(1200 W peak 450 W RMS) , and i am using sub-woofer filter also i/p of this amplifier , 24-0-24 5A Ac transformer,but when i raise the volume,i am getting poor effect( like vibration DURRRRRR – sorry i don’t know how to explain)with base effect ,i could not understand, what is the real problem , woofer also more than enough wattage rated with proper size enclosure ,transformer 5A rating . any body can please advice me .

    thanks in advance

    • sino says:

      Hi, please check the grounding.power supply grounding ,volume control grounding and speaker ground should be connected to different ground points. volume gnd should be away from power supply gnd point .

  • gayan says:

    can u please send me the list of components by a mail please .

  • ermsk8er says:

    Thanks!

  • ermsk8er says:

    Thanks for sharing your design, sir. Can u send me ur pcb layout for this circuit. Thanks again! My email – erm.sk8er@yahoo.com

  • migs says:

    dear sir..

    i want to try your 100wat subwoofer as my project in school.. can u sent it to me ur PCB layout and so with the components… thanks in advance..

  • Rahul Cinal says:

    Dear Sir,
    Please send me the parts details of this circuit board & thanks for the idea.

    Thanks & Regards,
    Rahul Cina
    Data Processor of Godrej & Boyce Mfg. Co. Ltd.

  • manish says:

    hiii can u plzz tell me whats d difference between a subwoofer amplifier and a normal 150 WATT amplifier…..
    can anyone plzz explain….
    plzz hlp..me i m making d 150 WATT amplifier

    • Janaka says:

      Sub woofer is a Mono Amp giving only the Bass ( Mostly) to a one Speaker. A Normal Stereo Amp is giving both Bass and treble to two Speakers. In a Sub woofer A Filter circuit also used to filter the sound so Treble can be minimized giving only the Bass. but again in a Normal Stereo Amplifier Filtering is not required. It gives both Bass and Treble equally.

  • manish says:

    Hi can anyone plz temme is ther any difference between a subwoofer amplifier and a normal amplifier I am going to build the 150watt amplifier how can I interface a subwoofer??? Plzzzz hlp me
    Thanks in advance……

  • S.alam says:

    hi
    can anyone please give me the PCB layout of this circuit
    “alamisdecent@gmail.com”

    thanking you..

  • omer says:

    hi sir seetharaman….

    i have a question in my mind that is dre any way to increase the output power of this amplifier?

    here’s one thing in my mind that if i use multiple transistors (2n3773′s) at the ouptput then is there any chance of increment of the output of this amplifier???????

    if yes then what will b the supply ratings??
    n how much i can increase the power by doing this modification ?

  • Kennedy Marquez says:

    Thanks for the circuit. Sir I want to do it. can you please help me, just send to my email the full detailed of the circuit including the part lists(also the electronic components connection), the speaker and the power supply that I will going to used. thank you very much sir.

  • pradipta pal says:

    i want to do a 5.2 channel surrounding home theater without programmer i.c. I want to know a circuit design using tl 084. But the i.c is not available where i live. Plz anybody give substitiude i.c design.

    • rohin says:

      hi pradipta pal,you can use lm324 in place of tl084 without any tension and it is available all electronics shops.best of luck

  • YED KRiz says:

    SEETHARAMAN sir tank u for this circuit…..
    sir can u please mail me the pcb layout of this circuit….

    SEETHARAMAN Sir,AS A FEED BACK,CAN YOU ATTACH THE PCB LAYOUT OF THIS CIRCUIT.BECAUSE EVERY ONE HAS DIFFICULTY TO FIND THE PROPER PCB LAYOUT OF THIS CIRCUT.IF YOU DO THIS,IT WILL BE A VERY HELP FULL FOR PEOPLE LIKE US

    • rohin says:

      HI YED KRIZ,don’t take tension about the pcb.i will make for you on 7th oct. on sunday.i will make it without power supply capactor and diodes.i want to help you all new people in electronics. seetharaman sir is great and they are doing a nice job for us.thank you n love u all

  • prakash says:

    Hi… can we use torroidal transformer…?

  • prakash says:

    Hi… plz provide the transformer specification and as well as recommended power supply circuit to the amplifier.

    • seetharaman says:

      September 9, 2012 at 9:43 am
      Hi Pramod you cannot, as 36-0-36 AC at transformer secondary will produce a DC of +51 – 0 – -51 volts. it will blow all the components. The maximum allowable transformer secondary rating is 25-0-25 volt RMS AC @3Amps, will develop around +36 -0- -36 volts DC best suited for this amplifier.

    • rohin says:

      hi everyone,transformer for this circuit is 26-0-26 ac.it gives 40-0-40 dc.for example ac i volt when we convert it to dc it become 1.4142volt dc.

  • sai ram says:

    sir please replay me fast sir i am waiting for u replay

  • sai ram says:

    sir i have center transformer which has teo outputs the outputs goes lie this 24-0-24 12-0 5amps can i use this transformer in this circuit bcoz 24+12=36v

  • omer says:

    for a complete PCB layout of this amplifier circuit just mail me …

    shining_star_12351@yahoo.com
    or
    engr.omer19@gmail.com

  • PRAMOD MANUJA says:

    THANKS SIR I GOT A BIG KNOWLEDGE FROM THIS CIRCUIT& I BUILT IT. IT IS WORKING.THANKS AGAIN ! I USED B857 FOR 2N6107,D313 FOR 2N5294.

  • omer says:

    hey guys, if any one is new to electronics and want to build or design his/her own sound systems then please visit my blog.
    containing all step by step instructions for building any kind of amplifier. I have started it from the very basic.

    http://www.universalcircuits.blogspot.com

    i have started this platform for all people who find their great interest in making their own circuits.

  • PRAMOD MANUJA says:

    SIR CAN I USE +36V / 0V / -36V 5A TRANSFORMER ?

    • seetharaman says:

      Hi Pramod you cannot, as 36-0-36 AC at transformer secondary will produce a DC of +51 – 0 – -51 volts. it will blow all the components. The maximum allowable transformer secondary rating is 25-0-25 volt RMS AC, will devolop around +36 -0- -36 volts DC best suited for this amplifier.

  • omer says:

    hey guys, if any one is new to electronics and want to build or design his/her own sound systems then please visit my blog.
    containing all step by step instructions for building any kind of amplifier. I have started it from the very basic.

    http://www.all-audio-amplifiers.blogspot.com

    i have started this platform for all people who find their great interest in making their own circuits.

  • mahesh says:

    hi Seetharaman sir , i have 12 -0 -12 tx & give me the pcb design ckt of 60W Subwoofer. Thanx

  • PRAMOD MANUJA says:

    sir please send me replacement for all of this transisters.if i use this replacement do i have to change transformer or any other part ?

  • Ofon udo says:

    I need a circuit diagram of a 100watt audio amplifier with four B688 and four D718 transistor

  • Suresh says:

    Any one can sent me the pcb design plz?
    This is my email.:Sures1997@gmail.com

  • Isaac Asante says:

    I never use before,i am now going to try.

  • sai ram says:

    sir this subwoffer gives only subwoofer effect what abt left and right speaker how to connect it in this circuit

    • Seetharaman says:

      Hi Sairam Sub woofer is the the one which reproduces below 140Hz. This cannot be heard but can be felt by body hence no directivity. One amplifier with suitable low pass filter getting the signal from both left and right channel information with a sub woofer box will take care of it. For left and right speakers you require a stereo amplifier to amplify left and right signal seperately and reproduce, which will give you the directivity.

  • Seetharaman says:

    Hi Predencio you can use.

  • Prudencio G. Peritos Jr. says:

    sir
    can i used 24v-0-24v 6A for this circuit?

  • Prudencio G. Peritos Jr. says:

    hello sir can i used 24-0-24v 6A for this 100 watt subwoofer amplifier?

  • ishan1211 says:

    Sir,
    I am waiting for your answer, my circuit is still on the table. Pls reply

  • Punam Pradhan says:

    I have all the required Parts for the 100 watt sub woofer amps. but without PCB I am little confused.If any one can send me PCB design will be great help for me.

    Thanks,

    Punam Pradhan

  • rohin says:

    hi dear seetharaman sir , this amp is good and its still working without any probelm. miss you and love you. you are one of the favorite person in my list.

  • krishna says:

    sir,
    Can u send me a circuit for 60w subwoofer circut

  • ishan1211 says:

    Sir,
    I made this circuit but power both transistor 3773 heatup withing few seconds, speaker is humming without a signal, voltage between speaker about 10V. sir what would be the solutions?

  • ishan1211 says:

    Sir,
    My transformer provide 35v, 0v, 35v. so how can i create +35v , -35v ?

  • sebin jacob says:

    Seetharaman sir,

    I am using this amplifier for the last one year.It is working fine and i am satisfied.You helped and guided me a lot during this project.Hope you r doing good.Always remembering your help.

    SEBIN JACOB

  • NASA says:

    hellow sir
    i want to made a simple circuit with woffer and spekar so how..??? give me daigram pls….. its my project nd by net i get a circuit but its very complicated so…..

  • Pankaj says:

    hello sir please tell me how can I add a bass and volume controller to this circuit?????

  • Pankaj says:

    thanks a lot sir now I had made the changes and my circuit is working perfectly……
    thanks again for your support and feedback.

  • Seetharaman says:

    Hi Pankaj you have to use 2N5294 only. since 2N5296 VCEO is only 40 volts. With DC + – 28 volts the circuit should work but will give you lesser wattage. With 18 volt transformer you will get only + – 25volts. try to use recomended components or else the circuit may not give satisfactory results. The component values are calculated for a particular supply voltage a deviation of a maximum of 10% only allowed.

  • Pankaj says:

    sir please help me my circuit is not working….

  • kanagaraj.s BE says:

    sir i want 24v single supply power amplifier circuit(nearly 30v) equivalent
    to stk 4392 plz send me

  • Pankaj says:

    thanks a lot sir but in my location there is no such person.
    is it possible that it is due to my power supply because Iam using +/-28 volt power supply?????
    In the power supply Iam using 18-0-18 volt 5 amp transformer.
    and sir Iam not able to find 2N5294 so Iam using 2N5296 is it possible that the problem is due to that transistor??????

  • Seetharaman says:

    Hi Pankaj check all your wirings transistor pins and diode polarities value of resistances capacitor polarities etc. Still if you are not in a position to fix the problem and if you are new to building of high power audio projects, please approach any knowledgeable electronic hardware engineer nearer to you, by physically viewing and analysing your assembly.

  • Pankaj says:

    Sir My circuit is not properly.Iam using a +/-28 volt 5A power supply.But my speaker is only humming doesnt produce any sound and the transformer starts burning after few seconds.Please suggest me appropriate solution…..

  • SYED OMAR MASOOD says:

    circuit diagram of ups 500w

  • SYED OMAR MASOOD says:

    I want a complete ups circuit diagram and also a line follower robot circuit diagra…

  • Pankaj says:

    hello sir could you please give me the board layout of this amp. Because I,am new to electronics field and not able to make a proper board layout.Please help me
    my email:-pankaj2892@gmail.com
    Thanks

  • Austyno says:

    Inverter circuit diagram output 220w

  • jocel says:

    hai sir, my hobby is electronics all my knowledge came from my own interest and patience i didnt go to school. im studying electronics on my own. and its hard. so please help me sir.
    may i ask you the formula of this amplifier and i will study it and give tips in designing audio amplifier.. thank you sir and God bless u all my fren… this is my email: http://www.jeoceltangdol@yahoo.com

  • seetharaman says:

    Hi Srinivasan you can connect it only through bass boost amplifier low pass filter is not required.

  • P.Srinivasan says:

    Hi seetharaman sir , i am using our low-pass-filter-for-sub woofer before this circuit ( for direct audio out ). can i add base booster pre amplifier with lowpass filter ,
    if i can , where i can connect low pass filter input or output stage ?

  • bal wolley says:

    I am building an infrasound device to be used in a spook house for a chairity fund raiser and need to build an amplifier that will not filter out the signals below 22hz. How do I configure this amplifier circuit to do this?

  • seetharaman says:

    Hi Srinivasan The recorded MP3 CDs are compressed ones they will produce only a flat response(but for the few genuine good quality recording). You can add a bass boost pre amplifier before feeding it to this amp. In the net you get plenty of such bass booster schematics use on of them.

  • P.Srinivasan says:

    Hi seetharaman sir, when i using orginal dvd or audio cd , i am getting good base effect form this amplifier , but when i using mp3 cd’s i could not get same effect even half also , what is the reason ??? what can i do for that ?

  • Sujeesh says:

    Hello sir,i want a tone controll seprator circuit that allows low freequency into this power amp’s input filter and other tones are seprate for other audio amp.please help me sir,
    my mail id is sujeejackson@gmail.com

  • techera says:

    wonderful

  • dav says:

    interesting.

  • Ajith says:

    sir..what type of heat sink the ,main transistor need…can i get an image of assembled this circuit..
    ajithsmn@gmail.com

  • shyam singh says:

    can i get the pcb lawout

  • seetharaman says:

    Hi Srinivas the relation for the output power is square of the voltage swing available across the speaker leads divided by the impedance of the speaker.
    The budget cost including power supply, with standard trasformer, good heat sink, PCB and with good quality low noise components will be around INR1200/-

  • P.Srinivasan says:

    Dear seetharaman sir,

    if input voltage is decrease below 30-0-30 then out put RMS power will decrease ????

  • sai ram says:

    sir wats the budget cost of this circuit

  • Ajith says:

    sir,i too think so..but i use a cooling fan also with it…does it can compansate it…??

  • Seetharaman says:

    Hi Ajith it should not become too hot it looks like your heat sink is insufficient, try using a bigger extruded alloy heat sink.

  • Ajith says:

    sir.,now my amp works fine..but .when it works for almost half an hour ,the 3773 s get hot as much as ,cant to touch it…
    Is it a problem or its usual??pls help me. .sir.,

  • rohin says:

    hi to everyone, i want to tell you that for good quality sound and high bass 2n 3773 is responsible. it made by many company like bel,toshiba,motorolla,china and local in delhi. you will get bad low quality in local and china made transistor of cost of 5 Rs. rest are cost of estimatly 50 Rs. so purchase right one for circuit.

  • Seetharaman says:

    Hi Harshit use our 150 watts amplifier with suitable sub woofer filter
    http://www.circuitstoday.com/150-watt-amplifier-circuit

  • ishan1211 says:

    Sir,
    I have bought every equipment’s in this circuit. my next challenge is design PCB diagram. it’s not very easy for me. if you can send me PCB diagram. Thanks
    E-mail: ishan1211@gmail.com

  • P.Srinivasan says:

    Dear Mr. seetharaman , can u please give me two channel switching circuit using audio signal detection that means one line normal condition , if 2nd channel audio signal detected 2 channel to be active and first channel to be disconnected.

  • harshit says:

    sir i want to make a subwoofer for computer please send send me a circuit of 150watt which is not so costly

  • rohin says:

    hi to everyone, i love this website and dear mr. seetharaman. this is not only a place where we make these projects and discuss. how we love each, to each other and respect. i am very empressed by you all and specially mr seetharaman. now i will give you, all my experience.May God bless you all.best wishes for holi.

  • kutty says:

    friends…i have a stereo amplifier..i would like to set a sub woofer to that amp..i got a sub board and i connected it…but the beat is very low..may i give the output of sub board to stk 4141 board and amplify it…my power supply is 12 0 12 3A transformer…is it enough..or any other reasons????

  • ALAM says:

    i have two speakers (max 70 watt, 6ohm)both
    i need a sub woofer amplifier design
    suggest me a design that produce heart pumping sound my mail is
    ((( alamisdecent@gmail.com )))

  • Ajith says:

    sir..can i??

  • Seetharaman says:

    Hi Alam Both are very important. a good amplifier with lousy speaker or a distorted low power amplifier with very good speaker is of no use. A rigid sealed enclosure is a must. the speaker can be little less rated than the amplifier for the best performance. A 100 watts @ <1% distortion amplifier with say 80watts 12" speaker or 40watts 2 nos 8" speakers in rigid sealed enclosure can give high quality thumping bass.

  • ajay says:

    hey rohin
    thanks a lot for ur time and advice .

  • Ajith says:

    thanks seetharam sir…i got ur mail.
    Sir.have a ups transformer with rating 6-0-6 />20amps[500va].can i use this transformer to obtain 25-0-25 /5A.,.

  • rohin says:

    yes, ajay my brother i am here to help you. i want to chat with you . i quicky solve your probelm . my no. is 9855427506. it is difficult to solve this by comments

  • alam says:

    can any one tell me that who is responsible for the high bass effect
    1 amplifier or
    2 speakers

  • ajay says:

    hey rohin
    can u help me with the circuit I have almost built it twice but still its not working.I have checked the transistor they are connected in right way .I have used c3 6.8uF 63v instead 0f 10uF and transistors bc547 instead of bc108. is it because of the bc547??? all my capacitors are rated above 100v except c3.

  • ajith says:

    sir..my e mail id is..
    ajithsmn@gmail.com
    thanks.

  • Seetharaman says:

    Ajith send your email id i will give ou a detailed checklist

  • ajith says:

    sir..i made this circuit..but its does not give any outputs..
    When i connected to supply both 3773 get heats up within seconds..how can i test the circuit…..sir,what may be the problem?pls help me…i made this circuit for my mini project at my clg…..

  • P.Srinivasan says:

    thanks for your confirmation

  • Seetharaman says:

    HI SRINIVAS HE IS CORRECT THE SAME I HAVE MENTIONED MUCH EARLIER ALSO.

  • P.Srinivasan says:

    Dear Mr. seetharaman , as on rohin comment C2 polarity is wrongly connected
    , its true ??

  • rohin says:

    TO making this circuit, you should know about the E C B of every transistor.if you conected it wrong then circuit will not work at all.2n 6107 and 2n 5294 , keep them front of your eyes( black side of the transistor , where is no. showing) left pin is base , middel pin is collector and the third pin is emitter.In 2n 3773 , keep it pin sides in front of your eyes and you will find that pins are much closer to one hole than comparesion to other hole , keep that hole to left which is much closer to pins and then upper pin is emitter and below pin is base and case is collector. you can use 5296 or 5294 or 2073.you can use bc108 or bc 109.check proper wiring it should be same as diagram showing.if everthing is ok. you should check your all transistor . you can check bc108 by multimeter hfe ports and its C B E too. for npn transistor, put postive on base and negetive to emitter, it showing 600or 700 ohm resistance like diode and negetive to collector it showing same as emitter but when negetive on base resistance should be high for both emiiter and collector. and to check pnp , it same like the npn only difference of postive and negetive leads

  • rohin says:

    hi to everyone, i want to tell you all that amplifier works fine and this circuit is high bass than 5.1 home theater. i already built it with the help of dear mr. seetharaman. he is a great person.there is one mistake in this circuit that c2 polarty is wrong conected. so kindly change it . otherwise there is everything allright. while making this circuit i face some probelm and i want to share it with you all.

  • manigandan says:

    i want circuit

  • seetharaman says:

    Hi Ajith a subwoofer amplifier is an amplifier with a good low frequency response and with a power of not less than 40Watts RMS at less than 1% THD & with good transient response.

  • ajay says:

    hey
    can anyone help me with this circuit please…. i have built this circuit but its not working .all my capacitors are rated above 100v except c3 which is 63v.used 2n5296 instead of 2n5294. c1 is 0.47mfd instead of 0.22mfd tested it with a 24-0-24 supply.Rest all are same components. what should I check in the circuit..

  • faishal says:

    sir tolong kirim ke email saya pcb layoutnya.trims

  • Ajith says:

    sir ,what is the difference between an ordinary amplifier and amplifier designed for subwoofers??

  • Awn Abbas says:

    Hi Sir seetharaman i want pcb design of this 100w sub woofer amp PLz Send me On my ID Plz Plz Plz

  • Seetharaman says:

    Hi srinivasan if output voltage is positive with respect to common zero reduce either R11 or 12 to next lower preferred value. if negative increase it to next higher preferred value

  • P.Srinivasan says:

    how to adjust the R11 or 12 value , value to be increase or decrease

  • regor wall says:

    gud day sir seetharaman ..! i want to build your featured subwoofer amp..can i ask for the pcb layout of this amplifier..pls email me..Wall.regor@yahoo.com.

    thanks in advance sir.. your reply is highly appreciated..

  • seetharaman says:

    Hi Srinivasan check the DC voltage across speaker. It should be zero. if not one may draw more current than the other. you may adjust the value of R11 or 12 till it becomes minimum, the problem is due to mismatch in the components.

  • P.Srinivasan says:

    hi seetharaman sir this amplifier working fine , but output one transistor heating more than other transistor . i am using 30-0-30 v Dc 5A

  • rohin says:

    hi seetharaman sir, you are great and i thanks to you very much for help me. now my circuit is working fine.

  • r.vijay dhas says:

    i want pcb design of this 100w sub woofer amp my id r.vijayadhas@gmail.com

  • Seetharaman says:

    Hi Rohin check your email for my detailed reply.

  • rohin says:

    circuit is not working for me

  • rohin says:

    i am wiating your help and response

  • rohin says:

    my mail id is rohin.sharma83@yahoo.com some one help me

  • rohin says:

    dear sir,i made this circuit but not working when i connect it to woofer R15 is burning please help me as soon as.waiting for your reaply

  • J S Nagaraj says:

    Please confirm me wether this blog is genuine or wether this website is a fake

  • P.Srinivasan says:

    Dear sir , i planned to keep the this amplifier kit ( including power supply unit ) into the sub woofer enclosure inside, there is any problem if woofer and transformer in one box ,

    SUB BOX DIMENSIONS KFC-W3013
    Sealed box volume 35.4 Litres
    Sealed Box Dimensions 475 x 362 x 299mm (19mm thick MDF)(WxHxD)
    Vented box volume 56.6 Litres
    Vented Box Dimensions 590 x 362 x 355mm (19mm thick MDF)(WxHxD)
    Port dimensions (labyrinth) (W x H x L) 38 x 324 x 546mm

    please advise me

  • J S Nagaraj says:

    Mr. Srinivasan, there won’t be any considerable problem because most of the
    2.1 channel amplifiers contain transformers in them but try to keep a bit far from the speaker.Try to shield the transformer if not leave it as it is.

  • J S Nagaraj says:

    Sir, Mr.Seetharaman
    I am not finding an exact input buffer and tone-control circuit for
    my STK4141 II amplifier board. Please help me with TOTAL amplifier circuit of the same.
    Thanking you,
    J S Nagaraj.