150 Watt amplifier circuit

Low Cost 150 Watt Amplifier Circuit

Description

This is the cheapest 150 Watt amplifier circuit you can make,I think.Based on two Darlington power transistors TIP 142 and TIP 147 ,this circuit can deliver a blasting 150 W Rms to a 4 Ohm speaker.Enough for you to get rocked?;then try out this.

TIP 147 and 142 are complementary Darlington pair transistors which can handle 5 A current and 100V ,famous for their ruggedness. Here two BC 558 transistors Q5 and Q4 are wired as pre amplifier and TIP 142 ,TIP 147 together with TIP41  (Q1,Q2,Q3) is used for driving the speaker.This circuit is designed so rugged that this can be assembled even on a perf board or even by pin to pin soldering.The circuit can be powered from a +/-45V, 5A  dual power supply.You must try this circuit.Its working great!

The preamplifier section of this circuit is based around Q4 and Q5 which forms a differential amplifier. The use of a differential amplifier in the input stage reduces noise and also provides a means for applying negative feedback. Thus overall performance of the amplifier is improved. Input signal is applied to the base of Q5 through the DC decoupling capacitor C2. Feedback voltage is applied to the base of Q4 from the junction of 0.33 ohm resistors through the 22K resistor. A complementary Class AB push-pull stage is built around the transistors Q1 and Q2 for driving the loud speaker. Diodes D1 and D2 biases the complementary pair and ensures Class AB operation. Transistor Q3 drives the push-pull pair and its base is directly coupled to the collector of Q5.

Circuit Diagram & Parts List .

150 watt amplifier
150 watt amplifier circuit diagram

Notes.

  • Remember TIP 142 and 147 are Darlington pairs  .They are shown as conventional transistors in figure for ease.So don’t get confused.Even though each of them have 2 transistors ,2 resistors and 1 diode inside ,only three pins ,base emitter and collector are coming out.Rest are connected internally.So its quite OK to assume each of them as transistor for ease.
  • Use a well regulated and filtered power supply.
  • Connect a 10K POT in series with the input as volume control if you need.Not shown in circuit diagram.
  • All electrolytic capacitors must be rated at least 50volts.

Power supply for this circuit.

A  +40/-40 unregulated dual supply for powering this amplifier project is shown below.  This power supply is only enough for powering one channel and for stereo applications double the current ratings of  the transformer, diodes and fuses.

amp supply

Power supply for this project

TIP 142 & 147 Internal diagram and pin out.

TIP 142-TIP 147 Pin Out Diagram and Schematics

TIP 142-TIP 147 Pin Out Diagram with Schematics

Note:- We have explained how to create a schematic of this circuit and its PCB using an online EDA tool – EasyEDA.  You may read the article to understand how to draw and develop a PCB of this circuit.

We have more related list of  Amplifier Circuits that you may like to visit;

1. 2 X 60 Watts Stereo Amplifier Circuitis designed using LM4780, an audio amplifier IC that can deliver 60 Watt RMS output power per channel to  8 Ohms speakers.  Advantages of using this IC are low harmonic distortion compared to other IC amplifiers of similar category and a power supply rejection rate of 85db. In addition it require minimum components and a built in mute function.

2. Headphone Amplifier CircuitThis is a simple circuit which uses only 3 transistors, that can be used to drive your headphone. It can be easily built by any one and can be powered using a 3 volts battery. 

3. Mosfet Amplifier Circuit - This circuit is designed using two Mosfet’s and one transistor; which makes it an easy to build circuit. It can deliver 18 Watts output power to 8 ohms speaker or 30 watts to 4 ohms speaker; you can do it the way you like it. Another advantage of this circuit is the minimal use of components.

4. 40 Watts Amplifier using TDA1514 - TDA1514 is a high performance hi – fi amplifier from Philips. It requires a dual +25/-25 volts supply. Advantages of using TDA1514 are low THD, mute standby feature, thermal protection and other features. It can deliver 40 watts of output power to an 8 ohm speaker. You need a proper heat sink for the desired reliability of this circuit.

5. 2 X 32 Watts Stereo Amplifier CircuitThis circuit is built using TDA2050 which is a 32 Watts Class AB Audio amplifier IC (monolithic) . This IC has many features like thermal shut down, low THD, short circuit protection etc. This circuit uses Two of these IC TDA205o; one for each channel.  An 18 volts dual power supply is required to power this circuit.

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1,004 Responses to “150 Watt amplifier circuit”

  • Youssef Aly says:

    I rebuilt the circuit on a breadboard with tip142, tip41c and four quarter watt 3K3 for a one-watt configuration. I test it with two computer power supplies (+12, 0, -12). TIP41C (no heat sink attached) feels cold, TIP142 and TIP147 along with the two 0.33 ohm 7 W resistors are HOT. The speaker goes half way to the negative direction and stays there with no sound coming out. Where should I check for pre-amplified signal and where should I check for drive signal from TIP41C ?

    PS: The PSUs are not exactly 12 volts unloaded, one is ~10.5 v and the other is ~11.3 v, both can supply 8 amperes safely on the 12 v rail. I have a (+45, 0, -45) unregulated power-supply, should I test with it or solve the issue at 12 V first ?

  • Nick says:

    How to start and what i need to build a very good sound amp

    • seetharaman says:

      What are your expectation. Hope your budget will not be constraint, if so project can be suggested.

  • Youssef Aly says:

    Sir, I built the circuit but I’m having problems, C2, C3 and R2 blowed up twice. I checked the traces for shorts but I found none. All capacitors are rated 50 V, R2 is rated 1/4 W. I’m using a 45 V dual supply. The TIP141 gets warm, TIP41C reflects wind like sound in the speaker, TIP147 is cool and on power up, the speaker cone moves forward and keeps it’s position until power is removed. Please help !

    • seetharaman says:

      Check TIP147 collector-emitter must have become dead short check all your wiring and polarity of capacitors, if they are interchanged( plus- minus polarity of the capacitor) it becomes a link wire instead of an DC isolator. A thorough check is required including D1 & D2.

  • abubakar says:

    thank u sir I did d same as u said and its working fine thanks a lot

  • Pl print full diagram with sp arts name in colour &its veroo bird number

  • Midhunmp says:

    Sir please give me a solution to solve ma problem. I have +/-40v 5amp supply. I made this amp. I using 4ohm subwofr. How can do to connect my woofr on my amp to get good perfomence. Is there any circut for connecting 4ohm load into 8ohm amp to get good perfomance? Please help….

  • Midhunmp says:

    How can i connect a 4ohm woofer in a 8ohm receiver. Is there any circut for it? Please help me sir….. I hope ur comment

  • abubakar says:

    sir I made d modification u told me i.e. Adding a diode n a 22/27 ohms in series with d two present diodes but am still having d crossover distortion.so I want to set the standing current but I don’t knw how to do dat (Whr to place the red and the probes)to carry out d reading and setting of the q-current. pls help me out sir.thanks

    • Seetharaman says:

      You can measure the milli volt drop across R8 and set it for say you are using 0.47 ohms then 0.47 * 0.06A = 30 to 40 milli volt and set for this value. If you cannot measure milli volt accurately. Use current measurement in the collector circuit of Q1. Break collector of Q1 to positive supply line and insert an ammeter and set the current for 50 to 80 mA.

  • Youssef Aly says:

    Hello, I can’t seem to find the TIP142, so I ordered TIP131f, is it ok ? I’m making a subwoofer amp by the way .

  • Lucas says:

    Hi, ive built this amp but it seems that the bass response is too high. What can i do to lower the bass response, maybe decrease the gain?

    • Seetharaman says:

      You can reduce the gain by increasing the value of 220 ohms of R2 to 470 ohms or 1K. That should take care.

  • usualfellow says:

    HELLO THERE, FOR BEST RESULT FROM THIS AMPLIFIER USE:
    1: 40-0-40 VOLTS TO 42-0-42 VOLTS 8 AMPERE DC POWER SUPPLY,THAN USE 12″ 4-8 OHM SPEAKER POWER HANDLING UPTO 150WATTS.
    2:IF YOU ARE USING 40-0-40 VOLTS TO 42-0-42 VOLTS 5 AMPERE DC POWER SUPPLY FOR BOTH THE CHANNELS THAN USE 12″ 4-8 OHM SPEAKER POWER HANDLING UPTO 100-150 WATTS.
    3: use 0.5ohm resister ,in place of 0.33ohm and add 680pf in tip142/147
    FOR STABLE OUTPUT
    4: HEAT SINK SHOULD BE PROPER,I HAVE USED 3″*3″HEAT SINK WITH FINS/OR BAR FOR TIP41,AND 4″*6″* WITH FINS FOR TIP 142,TIP 147.
    5: YOU CAN USE CLASSIC HEAT SINK OF 12″ WHICH IS USED FOR 2N3055 TRANSISTORS
    I AM USING 2*12″ WOOFER ,AND TWEETERS OF 4OHM LOAD WITH +-42V 10 AMPERE SUPPLY & use 0.5ohm resister ,in place of 0.33ohm and add 680pf in tip142/147
    FOR STABLE OUTPUT
    and the amp is running good trouble free since 1999

    • Seetharaman says:

      Thanks for your guide line. This will help others to take care and successfully construct the amplifier without any doubt and safely investing their money on the project. Thank you once again.

  • midhun says:

    Sir what should be the heat sink size?and is it safe to use 4ohm woofer with +-40v supply?

  • usualfellow says:

    SEETHARAMAN SIR DO YOU HAVE ANY UNIVERSAL PRE AMP CIRCUIT WITH BASS TREBLE AND VOL..IF YES THAN ALSO UPDATE US BY THAT

    • Seetharaman says:

      Yes I have the original Universal Pre amplifier appeared in 1972 Philips Application book. I will send soon.

  • usualfellow says:

    seetharaman sir i have made one circuit of 120+120 watt from efy book of 1986 circuit used TR 2N 6261,AND 2N6254,THIS CIRCUIT GIVES THE BEST SOUND I HAVE THAT CIRCUIT ALSO AND THIS DELIVER GOOD HIGH GOOD MID AND GOOD LOW,AND I MUST SAY 2ND BEST AMP I HAVE EVER MADE IN MY LIFE , AND SIR WHEN YOU COMPARE THIS 120WATT CIRCUIT IT BEATS THE TIP 142 CIRCUIT OF 150+150WATT CIRCUIT I HAVE ALSO COMPARED AND MOST OF MY FRIEND WHO USE TO MAKE CIRCUIT THEY ALSO DID THIS,AND SOME PROFESSIONAL LIKE NB BROS,(NAKRA BROS) CP DELHI GAVE ME THE SAME COMPLIMENT SOME SOME YEARS BACK BUT NOW A DAYS WE DO NOT HAVE THESE 2 TRANSISTORS
    I CAN USE 2N3773 =IN PLACE OF 2N6254,
    BUT I DO NOT KNOW THE REPLACEMENT OF 2N6261 WHICH IS EASILY AVAILABLE IN INDIA

  • usualfellow says:

    hi all use 0.5ohm resister ,in place of 0.33ohm and add 680pf in tip142/147
    i think than your amp go on without any problem ,i have made these changes in my circuit,and no problem

  • usualfellow says:

    seetharaman sir,i have three amp i am using in this time as you said this TIP142/147, CIRCUIT IS same and modified version of philips circuit 1972, but believe me sir the low is very good in bd182 circuit in compare to this 150 watt circuit,am currently using it,
    sir i have also observe that using 2N3773 TR,is gives more loud and low frequency in compare to 2SC5200 TR,,I tried many circuit.
    so please suggest me ,even your subwoofer circuit made by 2n3773 is gives good low freq.

  • usualfellow says:

    I am using preamp of philips amp made by mr. M.D hall,and it is giving terrific sound,with almost every amp,i have used it with more than 20 amps,gives terrific sound..

    in this 150 watt circuit i used 0.5/5watt resister,and rest circuit is same as above believe me than tere is no problem in your circuit

  • usualfellow says:

    hello sir ,i made the jspyne circuit same as shown on site but it decreases the sound output.but your circuit has no problem iam using it since 2009 and believe me it is giving sound trouble free on 45-0-45,10ampre supply and 150watt load of speaker

  • Youssef Aly says:

    Hello sir, I can’t seem to find the 0.33 ohm resistor in my country due to it’s high power rating and I don’t wany to order it online as it would be too costly, can I ommit it or replace it by a self made wire wound which I won’t know it’s power rating, or can you suggest other solutions ? Thank you in advance, regards, Youssef Aly.

    • Seetharaman says:

      Hi Aly you may get 1 ohm 2 watts which is a standard value, use 3nos in parallel to get 0.33 ohms 6 watts.

  • usualfellow says:

    IF YOU ALL BUDDIES COMP[ARE THIS CIRCUIT WITH JS PYNE THAN,THIS CIRCUIT SCORE 100/100,AND JS PYNE MODEL 40/100,SO BE CARE FULL sir ,SITHARAMAN IS VERY GOOD AND KNOWLEDGEABLE PERSON IN ELECTRONICS ,I HAVE SEEN MANY CIRCUIT MADE BY THEM WHICH ARE GOOD AND WITH GOOD EXPLANATION,,
    I

  • usualfellow says:

    hello all i made this circuit in year 2009, and in first attempt ,the output is good ,but ihave seen the problem is of low frequency,this circuit delvers good output and good mid,and high frequency,but when we talk about low frequency,than it is not good ,i am using sub woofer also but there is no good punch,
    and jspyne circuit cuts the output from the original one so do not try that i tried it 4 times with 1% resistors,and caltron cap,but no use ,jspyne circuit reduce the output upto 50%,than there is no use,so please you people do not waste time
    I have used 45-0-45 volts 10ampre supply

    1.i have made many circuits from net,from efy and other books i have tried 47 diff.circuits but i have seen only one good circuit which is made by philips company based on the book of M.D HULL,THIS delvers 25/40 watt RMS output by 0-60volts, TR BD139,140 AND BD 182,and delever you good sound even you do not have good speakers .
    2. I am not criticizing anybody’s creativity but TRUTH IS THIS ONLY ,so please help me out ,if you have good circuit

    • Seetharaman says:

      Hello that is the same circuit of Philips (from Philips 1972 Audio Application Book)I modified and used it in my Motional Feed Back Amplifier. In fact I have used 2 amplifiers in bridged mode to get around 150 watts into 8 ohms speaker.
      In the revision 2 of JSpyne the gain feed back circuit was changed to reduce the amplifier gain to R4 / R2 22K / 1K only 22 hence you require higher drive, comparing to original circuit. You can improve the gain by reducing R2 to 220 ohms. a gain of 100. 5 times better. It is customary to keep the gain around 50 in the output amplifier (for better frequency bandwidth)and increase the input through pre-amplifier to achieve the same output.

  • Tom says:

    Hi
    It is my plan to try to build this amplifier, however I have got some questions that I hope you answer:
    1. The specification says 150W in 4 ohm, do you know how much it will deliver in to a 8 ohm load?
    2. What size heatsink would you recommend?
    3. The transistors TIP 142 / Tip 147, would you recommend them in TO-247 or TO-220 housing?

    TIA and best regards

  • Midhunmp says:

    I made this circut. It worked perfectly. After on day i use it for my home audio systen but one problem a deep noise is producing this ckt and 0.33ohm resistor heating very much . I give +/-35v 5amp power suply and 10inch 4ohm woofer. I dont know what happent? Please give me a solution sir… And i have one more qustion can i use 0.2 ohm instead of 0.33 ohm? I hope ur replay… Thankx…

    • Seetharaman says:

      Use 0.47 ohms 5 watts in place of 0.33 ohms do not use a lower value. May be for interconnection you have not used proper screened cable. If you have a layout problem connect a low pass filter of 1K ohms resistance vs 470 pf in the input of the amplifier. connect also a 100pf capacitor between collector and base of Q3. refer (http://pcb.jspayne.com/150wattamp.html)

  • abubakar says:

    Sir i,ve found my flaw n its r2 conncted in d junction of r8 I
    nstead of been in series with r4.after correcting it it works fine.u d best

  • abubakar says:

    thank u sir 4 d response I will check dem n tell u d observations

  • john says:

    hi sir!! finally i found the solution for stereo from single transformer,
    (the problem is tip 41 is linked with heat-sink now i disconnect the link the problem is solved. now it works fine thanks a lot.!!

  • sonu says:

    Hello Sir
    sir I made this circuit first on bread board and it was working perfectly. but after 1 week when i made this again with new components this cicuit not working. . sir plz help me what should I do, i have to submit this project on tommorrow. . |
    kindly suggest me.
    Thank u

  • abubakar says:

    sir I can’t figure out wats wrong with my amp after building it I tought it will work fine,but instead I’m only having a very little sound @ d output . pls help me sir. D one I made the first time worked fine. N I couldn’t get 3.3k @ 1watt so I used a 2.7k n a 750ohms resistors in series. Wen I read d value across d two resistor with my dmm it showed me 3.35k pls sir suggest me on wat to do.could it b dat my resistor combination led to d@ problem?

    • Seetharaman says:

      No. you resistance combination is ok. Check C1, C2, C3, R2 and R4 for correct value or a defective component.

  • mian mubshir says:

    sir how many voltge we can apply on its input .

  • Midhunmp says:

    Sir i place tip142 and 147 on a heatsink, suddenly the loud noise stoped. Now there is no sound in my circut. I dont know wht happent.? Please help me sir

    • Seetharaman says:

      Mostly transistors might have blown. Use cold check with a multimeter to find out damaged components. check the wiring and component values and polarity of each component used. use 33 ohms 10 watts resistance in positive and negative supply rail before switching on again after thoroughly inspecting the assembly again. If any one of 33 ohms smokes switch off immediately and look for the mistakes and correct it. Still if you cannot solve the problem kindly contact a local friend who is well versed in assembling high power amplifiers to help you. If this is the first time you are assembling a high power amplifier it is better take an advice from a local professional in assembling and proceed.

      • john says:

        place mica sheet between tip142&tip147&tip41 and heatsink.check out and confirm there is no link between heatsink and those transistors.

  • john says:

    Hi sir !! i bought another transformer for stereo….

    the transformer’s secondary voltage is 30-0-30 5amps,
    now the dc voltage is +60/-60 and 0(GND) after bridge rectifier.
    can i use this volt. or need any changes to this amplifier ckt??

    • Seetharaman says:

      Looks like a poor quality transformer with bad regulation A 5amp transformer of 30-0-30 cannot give plus minus 60 volts it can give only plus minus 45 volts at the maximum. Kindly use series regulators and reduce the voltage to around plus minus 40 and use. for 60 volt plus minus this amplifier will get burnt you may have to replace all the semiconductors and capacitors with higher voltage rating, which are very expensive.

  • Midhunmp says:

    Sir i use +/-35v dual power supplay and 10 inch 4ohm load. I made the pcb layout of this amp using the link you are posted on the site (http://pcb.jspayne.com/150wattamp.html)
    please solve my problem sir,

    • Seetharaman says:

      Place a wire link between Q1 and Q2 base and energize and see if not getting heated up. It looks there is a problem in 1N4007 diodes. If it is still getting heated up check TIP147 for collector emitter short. Are using 18 SWG or better DC power connecting cables and are they less than 2inches. While switching what sound you are getting from speakers.

  • Midhunmp says:

    Sir, i have one problem on my ckt. When give supplay to my circut a loud noise producing. I dont get 0.33 ohm 7watt. But i got 0.33ohm 2watt. I use 2 nos of 0.33ohm 2watt in series and connect parallel with another 2nos of0.33ohm 2watt in series. Tip 142 is heating very much and 0.33ohm resistor in tip142 is heating very much. Tip 147 is not heating. I dont know what is the actual reason of this. Please help me sir to overcome this . I hopeing ur comment. Please

    • Seetharaman says:

      May D1 & D2 is wired

      • Seetharaman says:

        May be D1 & D2 are wired other way round that is anode/cathode inter changed. Check collector emitter and base of TIP142 & 147 for correctness. Check the healthiness of TIP147. How much DC you are feeding to amplifier. What is the speaker impedance. What about the input to the amplifier whether connected to ground or left open. Have you taken care of short length of DC power supply cable should be less than 2 inches. Check all the wiring and your layout and DC supply do not exceed plus minus 35 volts DC. Please give more details to give a solution.

  • Akku# says:

    Sir,the transformer shown in the power supply has a 30-0-30 output,can you explain how it get increased to 40-0-40 V at o/p after filtering.
    I am building a 5.1 amp,i have a 30V 6A single supply transformer for powering the 5 channels(2xTDA 2050+3xTDA 2030),after filtering the tranformer with a 4700mf capacitor how much voltage l get as o/p…??
    ,i am thinking to add 100W amp(mensioned in this site)for sub woofer,is this configuration is correct…..i’m a beginner .i really liked this site..frgve for my bad eng…..waiting for your replay…

    • Seetharaman says:

      If you use 320 volt RMS AC voltage transformer the DC output will be peak of RMS voltage after rectifying and filtering. THAT is 30 X 1.414 = 42 volt s DC. you will get +42 0 -42 volts DC. you will get 42 volts TDA2030 will get damaged it requires a maximum of 36 volts for 4 ohms load speaker. use only 24 volts transformer. for TDA2050 it is ok as 44volt dc is max allowed.

  • Midhunmp says:

    What is the minimum voltage required for run this amp?

    • Seetharaman says:

      Minimum is + – 30Volts DC and Maximum is + – 45 volts DC with the components indicated. with + – 30 volts DC you will get 85 watts into 4 ohms load and 42 watts into 8 ohms load. with 45 volts 100watts into 8 ohms load 4 ohms load not recommended, will damage output transistors instantly.

  • Midhunmp says:

    Sir what is the minimum voltage for this amp?

  • suresh says:

    i need tip 41 eqiuvalent

  • Midhunmp says:

    Thaks seetharaman sir

  • Midhunmp says:

    Sir please replay me sir. I want to build a 5.1 system using above amp . So iam waiting for ur replay…

    • john says:

      i m also want to build 5.1 using this circuit. i build stereo but this is not successful for stereo………….. but for mono this gives very good output.
      if u find any solution for 5.1 plz share here..thank you!!!

      • Seetharaman says:

        Hi John this is a good stereo amplifier provided the layout is taken care by using thick cable for DC power supply and one point earthing and screen not connected at both ends etc. this project is not just for a beginner. High power amplifier are a bit difficult to assemble. this can be used or sub woofer amplifier and you can use TDA 2030 or 2050 for the surround front left, right and center speakers. This way you can achieve a nice 5.1 ssystem

        • john says:

          sir thanks again for another reply!! i build this darlington for left right. And for subwoofer i use TDA7294 ic (100watts rms). and i use stk 4141 for center and rears. But there is a problem with this left right channels. both channels inputs are comes out through both left and right channels. this is only my problem. i use unregulated +44/-44 and GND power supply for all these amps from single transformer.is this problem? i think this is the problem. thanks again!!

          • Seetharaman says:

            Proper decoupling and high value filter capacitors and proper layout and earth loops are a must to avoid cross talk between channels

          • john says:

            ok sir … i ll try again …. and i ll show you that amp. thanks again!!

  • Midhunmp says:

    Sir i don’t get 0.33ohm 7watt resistr. But got 0.33ohm 2watt. Can i connect above 0.33ohm 4 resistor in series to get 8watts? Please clear my doubt sir. Iwant to finish my circut. Please help me sir,

    • Seetharaman says:

      you can use the standard 0.47 or 0.5 ohms 10 watts which are available readily in the market.
      If space is not at premium in your amplifier enclosure you can use 2nos 0.33 ohms 2 watt in series and connect in parallel with another 2nos 0.33 ohms in series to achieve 0.33 ohms 8 watts finally. Choice is yours.

  • Midhunmp says:

    0.33 ohm 7watts resistor not available in my area. Only have 0.33ohm 2watts. What can i do for this. Please help me seetharaman sir. I want finish my amp when clear this problem. Thanks

  • Midhunmp says:

    Plz sir i am waiting for ur replay……

  • Midhunmp says:

    Can i use a rectifier ic for 6a5 diode in the power supply circut?

    • Seetharaman says:

      Yes you can use 6A5 it is 6Amps 500v PIV rectifier.
      Please use any circuit which uses dual supply(both plus and minus voltage with zero volt reference)To get +12 volt use 7812 12 volt 3 pin regulator ic, for positive supply and to get -12volt use a 7912, a 3pin negative voltage regulator ic.

  • Midhunmp says:

    Sir i want to builda a subwofr filter using my +35/-35v 5amp dual power supplay . I saw a filter circut on this site using +12/-12 dual power supply. Please give me a solution to convert 35v to 12v. Iam waiting for ur replay. Please sir ..

  • Midhunmp says:

    Sir
    I have +35v/-35v 5amp duel power supply. If i connect my supply to the power amp, how much power will get 10inch 4ohm load. Please clear my doubt sir. I’m hoping your replay, have a good day.

  • john says:

    sir can i place one capacitor loop with one resistor from the positive pin of speaker to ground for my mingle problem? if i place it what happens?

  • john says:

    AND i use this as subwoofer amp. gives GOOD output .
    .
    BUT i m sorry to say this. THE output of stk 4141 for subwoofer is better this one.(for best effect i use the power capacitors value is 10000/50v*2 for dual)
    OTHER than subwoofer amp. . this darlington are rocks (better use for left right)

  • john says:

    finaly i use split and pin protect ciruit power supply as you given the link. now i use single tranformer for two(stereo) channells. it works good. …………
    BUT. . . . one major problem that is the input of both chanells are amplifying through both channells. . that mean the input of 1st channel is amplifying through both channel. . AND also 2nd channell input also amplifying through both channels. . BUT no dissorted audio. CLEAR output. PLZ give some solutions for this . . THANK you sir!!

    • Seetharaman says:

      Chech your layout. The power supply should run independant cables to each channel

      • john says:

        i use independent circuit of output transistor pin short protection for each channels. and also completely i trace out the circuit for any mistakes. there is nothing to problem. except the ground(0volt) is common.i think this is the problem. because both speakers are looped with common ground volt. this may short with the other end of the output of each channels. but i cant understand this problem.bcoz of my poor knowledge.
        FINALLY I REALIZE THAT THERE IS NO WAY FOR STEREO FROM ONE TRANSFORMER.
        SEPARATE TRANSFORMER IS THE ONLY RIGHT SOLUTION.

  • Midhunmp says:

    Thank you sir, god bless you.

  • Midhunmp says:

    Sir
    i use this circut as a subwoofr amp. If i use 25 volt 5amp ac with 10inch 4ohm subwofr what power actually get?

    • Seetharaman says:

      You have to use 25 – 0 – 25 volt @ 5 AmpAC transformer with bridge rectifier and filter capacitors to get both +ve and -ve power supply required for the amplifier. please refer to the power supply circuit given in 100watts sub woofer amplifier.

  • john says:

    plz help sir! i finished one channel. it works perfectly. but i made another channel for stereo. here the problem that the first channel input amplifying through both channels. and the second channel input is dead.(no audio) and also the heat is abnormal. what is the solution for this problem.plz help.

    • Seetharaman says:

      If you are using single power supply for both the channels disconnect first good amplifier connect the one getting heated up by putting a link between Q1 and Q2 base the current through output transistors should fall and the if audio input is supplied it should sound distorted. If it is not achievable check the complete wiring and for a defective component, isolate replace and rectify.

      • john says:

        i use dual power supply. i found the problem with power supply. that is i gave the supply for both channels from one tranformer.(this is the problem) AND i need solution for power supply for 5.1 using this circuits from only one transformer(sec=24-0-24). IS THIS POSSIBLE ??. If it is possible i m very lucky. THANK you for your response sir.

  • john says:

    i finished this circuit it runs smoothly and there is no abnormal heat, wow!! great sound ………… its enough for an home!! before making this..i asked an shopper about 150 watt 5.1 amp. they says 3500 rupees for 6 channels. but this cost just 200 rupees per channel with big heat sink. so i m happily says “thank you admin”. now i m going to make 5.1 using this circuit

  • Rituraz says:

    Good evening Sir can you please help me!I m new in electronics I can’t find tip142, tip147, tip41 Can I use other power transistor instead of these tips I like to making electronic kit. And I also want a perfect amp circuit diagram in one channel with parts list include watt which produce 200watt with deep bass. I m waiting for your answer. Thank in advance.

  • saeed says:

    can i use a 4ohm speaker instead of 8ohm ,which is written in the first figure?or i need some modifications?

  • Trollman says:

    Hi, i wanted to ask, can this circuit be used with an antenna rather than a speaker???

  • amer says:

    Sir can bc558 be replace by 2n3906 ,and tip147 and tip142 replace by note 270 and note 271

  • raymart says:

    nice circuit

  • abubakar says:

    sir I have finished assembling dis circuit and d sound is quite good bt d only problem am facing nw is one of d output transistor heating up (2sb1560) but d oder transistor (2sd2390) heat is normal.pls sir how can I fix dis problem? am using bc557 at d amplified stage

  • abubakar says:

    pls sir I cldn’t find bc558 can I use bc557 instead? n I have d2390 transistor is it dsame with 2sd2390? Pls sir am waiting ur reply sir thanks

  • abubakar says:

    dear sir seetharaman, I am new to electronic n I have so much interest in building dis circuit.pls sir I need ur assistance.Whr I am I couldn’t find bc558 and tip147. Pls sir I need to knw wat other transistors can I u instead? I will b waiting ur reply sir. Thanks

  • omer says:

    Hi… Seetharaman sir i have question for you sir..
    i have designed this amplifier in stereo and using dual transformers 25-0-25 for each channel and using a stereo pre amplifier ( bass treble kit) .. All is ok the amplifier is working perfectly and giving me a pure 150 watts output i think more than 150 watts because its running my 4 12 inch speakers very smoothly…
    I am facing a problem when the amplifier’s sound is low then it does not give a clear output it gives me a distorted output and when i increase the problem it gets fine…
    i need to know that what is the problem exactly ?

  • Aqeel Ahmed Khan says:

    sir pl Sher PCB Lay out 150watt amplifier circuit & ton control

  • PRINCE IGBO says:

    Sir Happy New Year and im still Waiting for your reply on my Post

  • PRINCE IGBO says:

    Sir how can test the Tip142 and 147 to know if it is dead. My first circuit worked perfectly and what if the fuse is removed, will cause the transistors to over heat. This circuit im doing now is mine. But the other one i did i sold out. Please i need ur reply as soon as possible my father is on my neck. Thanks alot. I will be waiting. Or send it to my Email address (princestechnology@gmail.com)

  • PRINCE IGBO says:

    Please what if the fuse is removed can it affect the working of the circuit. My question is that what is the work of the fuse. Please i need reply urgently Thanks for reading.

    • Seetharaman says:

      By deleting fuse your protection to the amplifier is lost in the event of speaker leads are (amplifier output) shorted both the output darlington transistors will blow off. You can test the transistor with a multimeter in diode test mode. being darlington transistor forward continuity of base emitter junction will be 1.2V and Base collector will be 0.6. collector emitter in reverse bias will be 0.6 due to built in protection diode (see internal details shown above)and forward continuity will be open circuit.

  • PRINCE IGBO says:

    Mine is working perfectly. I love Circuitstoday or even circuitsforever. Thanks im getting rocked

  • Andrew says:

    Circuit works great! Is there any way to increase gain in preamp stage? I’d like to use a phono directly, and been having a hard time eliminating rf noise

  • Biju Raj M.K says:

    Sir,
    Please help me. 0.33Ohm 10 watt(connected to TIP 147) resirtance very hotted up and no output

  • G S Khokhar says:

    Sir,
    To enhance output can I use BDW83C & BDW84C in lieu of TIP 147/TIP142 or any other MOSFET? Kindly suggest. After changing Transistor how should I combine two sets (left & Right Channel) of amplifier to produce enhanced output. Kindly draw a diagram. How much supply DC votls and Amperes need for Single pair and combined pair?

  • Krishna Reddy says:

    Hi all,

    I have a couple of 32-0-32 volts @ 4Amp and 40-0-40 volts @ 5Amp trafos lying around at home.

    So I thought of building an amp which can use them. Any schematics for something like this? I haven’t searched on the net, maybe there are some amps out there. In terms of audio quality, the most important thing is CLEAN and BALANCED sound. We need to hear the little things!

    I was thinking to build a set of mono block amplifiers, not too fancy but nice enough for my Dynaudio Audience 42W speakers. Can someone help me point out some amplifier designs? Think I can handle a build completely from scratch.
    So what is a wise decision? I estimate, with these supplies you should get around 150 watts.

    Thanks In Advance
    Krishna Reddy

  • sir if i want to continue the output stage with one or two power transisor where will i connect the base of the transistor

  • Tilen says:

    Hi!

    Im not sure whats wrong with my circut because if i mesure the pins where is speaker output i got 37V,and tip41c get really hot but the other two are cold (Im testing without speaker and MP3 only power supply). I hope you could help me with solving the problem. Thank you.

  • malinim says:

    I would like to drive an 11 ohm speaker from this 150 watt amplifier. I only require a 105 watt output. Using TIP142GOSND and TIP147GOSND both rated for 100v@10amps, I estimate the supply would require around +/- 90vdc. The circuit appears to be able to handle the load if I use all components rated for the increase supply voltage. Do you recommend and changes to the original design? or have any suggestions to drive the 11 ohm load?

  • Rex says:

    Seetharaman, i cant find 6A5 diode. But i have 6A10 DIODE can i use it, or will the current be too high?

  • Rex says:

    Seetharaman, i cant find 6A5 diode. But i have 6A10 DIODE can i use it to replace 6A5

    • seetharaman says:

      Hi Rex you can use 6A5 is 6amps 500PIV rectifier. 6A10 is 6 Amps 1000vols PIV rectifier. both are suited for the project.

  • jayanath says:

    Request indicate the best circuit for public address system amplifier. with use of 18 inch horn.

  • Rex says:

    Seetharaman, i want to make the POWER SUPPLY CIRCUIT but i cant find 6A5 doide. Please i need other Doides for replacements.

  • Rex says:

    Seetharaman, i want to make the POWER SUPPLY CIRCUIT but i cant find 6A5 doide. Please i need other Doides for replacements

  • omer says:

    We have built this circuit about more than 1000 times this works well and perfect..
    If you are facing any type of problems regarding this circuit then you can contact us any time….. we are here for your assistance
    We have a complete tutorial ( images as well as videos ) of this circuit’s building procedure…
    If you are realy willing to built this circuit with perfection then contact us below given mail…. we are here to solve your problems… thanks , have a good day
    engr.omer9@gmail.com

  • omer says:

    If anyone wants this circuits clear PCB layout then please visit my link
    by clicking on the tab “150watts amplifier PCB board”

    www . it-tronics . blogspot .com

    thanks…….

  • alele moses says:

    someone help me with this, i used a scopemeter(CRO) to monitor the progress of the input signal from the signal generator into the amplifier and at the emiter of Q5 there was less amplitude than from the base and and moving forward it was becoming less and less please i need to know was it because of the lower voltage (-+22.5) i used or there could be some other problem please could it be darlington transistors thanks

  • alele moses says:

    hi seetharman, i switched on the power supply and the tip 142 heated up very first and eventually the volume of the speaker deminished,the tip 142 cooled and i again switched on the power supply but there was no heat as if the tip 142 was dead. even there was no sign of heating in tip 41 and tip 147 are they dead.i also want to know how i can get some results of the amplifier using the signal generator and the CRO coz i tried and there was no change in the output from the CRO with respect to the input signal ie there was no amplification effect, how can i get this.

  • ALELE MOSES says:

    sory for the mistake the speaker impedence is 4 ohms please read my coments below this

  • ALELE MOSES says:

    i used the lower voltage because some of my components were at first blowing and burning with higher voltage but i think i can now increaase the voltage thanks to mr seetharman for your wonderfull work

    • Seetharaman says:

      Hi Moses you can increase the supply voltage to + / – 36volts DC (the upper safe limit with 4 ohms speaker).

  • ALELE MOSES says:

    Hi mr seetharman thanks alot for guiding me up to this point the circuit is working but i used +/-22.5V to power the amplifier and the output was low,i also noticed that the TIPs are not heating as expected,i used a DVD as my audio input. so my question is, could it be the low voltage that i used or my TIPs are dead? the speaker is 150watts 5ohms.

  • ben says:

    nice amp works great…i assembled 8amps with this circuit good high freq. and low frequency response using jrc 4558 ic as tone control..i used it for lead guitar, bass guitar & keyboard…i even use tip41/tip42 & tip2955/tip3055 as darlington pair as output x’sistor with supply voltage of +/-40vdc @6amperes…using dual voice coil speaker @ 450watts 4ohms…heat is minimal low noise no hum…

  • omer says:

    150 watts tda2030 / tda2050 subwoofer amplifier circuit now available here

    www . it-tronics . blogspot . com

  • turk690 says:

    This circuit works, but D1 & D2, which are supposed to provide the bias for the “A” part of the class AB description, can come from anywhere and therefore have unpredictable actual forward voltages. Garden variety 1N4007 diodes can have forward voltages ranging from 0.3V to 1V! The lower this voltage gets may result in audible crossover distortion, and the higher it is, Q1 and Q2 may conduct heavily (more A than B, at all times including no-signal conditions), become very hot and die if not properly heatsinked! It would probably matter little if this was a lower-power amplifier (<40W), but for a design that aspires to 150W, a transistor in place of D1 and D2 whose base is connected to a pot that can fine tune the bias voltage is essential, IMHO (the www is filled w circuits for this).

  • Olabode says:

    Dear daniel,ur problem of over heating on this amplifier configuration can be solved by changing only one copmponent on the circuit.For more knowledge on this,email me on “olabodejoseph@gmail.com”

  • daniel says:

    well, i used a heat sink for TIP142, but wasn’t that big and i also placed a fun beside it which reduced the temperature to some extent, but the sound still distorts and diminishes eventually. when this happens, i turn it off for it to cool. when turn it on it takes a longer time for it to sound and the sound is even very low and noisy.i will have to turn it off and wait for a very long time, even though the tip142 is cool before it sounds. it doesn’t end there, it still over heats and the same thing happens again……Anyway,tip 147 doesn’t heat at all. it remains cold while tip 142 becomes hot. i don’t know if there is something wrong. it looks like all the work is on tip142. I will get a bigger heat sink to try and see the results.

    • omer says:

      you must replace your both the transistors …… thats not the issue of heatsink

      • daniel says:

        okay, thank u very much. but then i want to know, tip142 and tip 147 are darlington pair transistors with side base, but i do a diode-test of these transistors, they read as side base and they can also read as if they are center base. is that the nature of these transistors? that is how they were when i bought them from the market.

    • Seetharaman says:

      Hi Daniel may be your TIP147 is dead short between collector and emitter. check with the multimeter for this and if required both TIP142 and 147 with a matched pair transistors.

  • alele moses says:

    hi seetharman i used +-22.5V to power the amplifier and every connections seemed to be ok but when i connected to the signal generator for the input signal,the output from the CRO(CATHOD RAY OSCELOSCOP)was smaller than the input meaning there was deamplification instead.please i need also to know into details how the preamplifier and darlington pair works on my email ,could it be yhe lower voltage i used please coment.thanks regards.

  • daniel says:

    Hi Mr. Seetharaman, the amplifier is now working, but tip 142 becomes very hot when i power it, and the sound eventually becomes noisy and finally diminish.in any case i am using c558 instead of bc558. i don’t know if it is going to be a problem.

    • Seetharaman says:

      Hi Daniel Hope you have used a large heat sink for TIP142 & 147 (a good extruded alloy heat sink not less than 6″ X 2″ X 2″)

  • alele moses says:

    Hi mr seetharman my capacitor C2 10mf 100V blew of when i powered it but before blowing it was not allowing the signal input to flow untill i had to shotit,please could there be any problem with this capacitor or could it be some where else, coment (these are the changes i made, i replaced 0.33ohms with 0.47ohms 5W and i used 120pf capacitor instead of 100pf and two 15-0-15 3A TRANSFORMER in series insted of 30-0-30 5A)the way you wrote to me and my power supply was +46/-46V.

  • Rex says:

    Seetharaman, thanks for this 150W AMP circuit, but we need high power amplifeir like, 200W, 400W, 500W etc

  • alele moses says:

    hi mr seetharman, i powered my amplifier with -46/+46 volts power supply that i made using the 2 15-0-15 3A transformer and the 220 ohms resister got burnt so i am asking my self could it be that the resistance was too small or the watage i used and i have bought half watts instead of quarter watts please coment on this. i also want to use the signal generator and the CRO to determine some x-tics of this amplifier.please coment on this.

    • Seetharaman says:

      Check polarity of C3 and also for a collector base short circuit in Q4 or there may be some wiring mistake or transistor leads identification wrong. 1/4 watt is sufficient for 220 ohms.

  • daniel says:

    thank u very much for the reply.i have done the modification and it can now pick the sound of the mp3 at a lower volume. but it gives a hazy sound with background noise “puf…puf” with breakage in the sound what can i do to get a clear sound?

    • Seetharaman says:

      Hi Daniel you may please go through my 2nd July comment. Implement all the modifications indicated in the second circuit it should take care of all your layout problems.

  • Rex says:

    Seetharaman, Thank you for your response, what about 1N5408 Doide, can it replace 6A5 Doide?

  • Rex says:

    Hello, Can i use 1N4007 Doides to replace 6A5 doides in the power supply circuit?

    • Seetharaman says:

      Hi Rex 6A5 is 600volt PIV, 5 Amps rectifier diode. You can use any 200PIV 5 to 10 amps rectifier 4 nos or a single 6 amps 400PIV bridge rectifier

  • Rex says:

    Can i use 1N4007 Doide to replace 6A5 doide in the power supply circuit?

  • ALELE MOSES says:

    hi mr seetharman i was able to get 8 ohms 800 watts speaker,can this work for me. trhanks

    • Seetharaman says:

      Hi Moses you can use 2nos above amplifier in bridge mode to drive 800watts speaker with reasonable quality. If you can get 100 watts 4 ohms speaker use two nos in series to achieve 8 ohms 200 watts.

  • ALELE MOSES says:

    please i have failed to get the speaker of 8 ohms,please some alternatives

  • daniel says:

    thank you very much.but my problem is;
    -i have built the amp and it is working, but the sound is very bad. i also have to open my mp3 player to the maximum volume before the sound becomes stable, which is even a bad sound. what can i do about it?
    -also, the voltage specification of the capacitors. whenever i go to buy the components, i am challenged with the voltage, since one capacitance value can have different voltages. are there any means of detecting the voltage required?

    • Seetharaman says:

      Hi Daniel check with no signal input to amplifier check the current drawn by the output darling-ton pair (by measuring their collector current) It should be between 50 to 60mA if not adjust by adding a resistance of 10 to 27 ohms and a diode IN4007 in series with D1 and D2 once this current is achieved it should work nicely.
      Refer modified drawing in the following link
      http://pcb.jspayne.com/150wattamp.html

  • mehru says:

    HI. I can’t find speaker of 8 ohms with 150 W. Is there any alternative?

  • ALELE MOSES says:

    Thanks mr seetharman for your advice and am doing it but i need image of the pcb connection of both the power supply and the amplifier on my email if possible the videos of the connection.please sir i need this because i want to avoid loss of some components due to connection mistakes because we have very limited components in the market.

  • atamosa says:

    hi good day to you mr. seetharman….my question is…how to connect in serries of two 15 0 15 3A transformer to get 30 0 30 6A?…..plz reply with this question….

  • ALELE MOSES says:

    we also have other types of transformers but with less than 3A, my phone number is +256779268591 please i need your help on this gud time

    • Seetharaman says:

      Hi Moses use the full winding without center tap of 15-0-15 3amps transformer. It will be 30 Volts. Use one more transformer in the same way in series ensure it gives 60 volts end to end if not interchange one of the transformers secondary winding connection. it will be 60 volts end to end. and use the inter connection between transformer as center tap. Now your power supply of 180 watts is ready. this can easily power your amplifier one channel. do the same for other channel also.

  • ALELE MOSES says:

    Hi mr seetharman i have almost made all my connections but my main problem is the transformer. we only have 15-0-15 3A transformer in the market please advise me about this,i also need the pcb connections in my email(alelem@rocketmail.com) may be if possible the videos.thanks

  • Gordon says:

    I am looking at this circuit and cannot understand how 2 X 1n4007 diodes are able to bias the output transistors (darlingtons) into conduction, surely you would need at leat 4 diodes, to bias the 4 Vbe junctions? Yet many have built it and say it works well, what am I missing?

  • ALELE MOSES says:

    I WAS thinking of using 15-0-15 3A AND 15-0-15 2A in series coment on this sir.

    • Seetharaman says:

      Hi connecting two transformers in series will increase the voltage but the current will be the same, if they are identical transformers. this is the basic. Please conduct the experiments and give a feed back by using different complex combination of transformers. please check your mail.

  • ALELE MOSES says:

    thanks mr seetharman for u reply but there is one thing confUsing me about the transformer coz last time u told me to use 2nos 15-0-15 3A transformer and connect in series and it will give 30-0-30 6A my question is what about the TIP 142 AND 147 transistors which requires maximum current of 5A, WONT THEY OVER HEAT WHEN I USE THOSE TRANSFORMERS IN SERIES SINCE THEY WILL PRODUCE 6A.

  • ALELE MOSES says:

    sir i think sending me a full report may also help me understand this amplifier into details.please i need a report for this design on alelem@rocketmail.com thanks

  • ALELE MOSES says:

    Thanks alot Mr seetharman for your reply coz you have given me another hope of coming out with what the project requires and i think i need to know how you are coming out with some of this calculations of like the output power, input signal and the output voltage of the power supply.may be on my email;alelem@rocketmail.com, good day sir.

  • Alele moses says:

    sir, i was able to get 0.47 5W resistor that you told me about except that i couldnt find the 15-0-15 5A transformer and am going to use 15-0-15 3A TRANSFORMER and i will try to measure the output voltage.what do you suggest about the fuse coz am still using the 5A fuse and am going to use the 6A10 diodes in the bridge but am not going to change other components in the power supply appart from what i have stated above.i hope i shall go to the amplifier after the power supply.thanks alot mr seetharman for your wonderfull work i have already learnt alot even before finishing the project.meet tomorrow.

    • Seetharaman says:

      Hi Moses you can use 2nos 15-0-15 3amp transformer in series to get 30-0-30 6 amps. with the above power supply and 4 ohms speaker you will get 150 watts output with 8 ohms speaker around 100 watts out put power with an input of 300 milli volt rms signal.

  • ALELE MOSES says:

    i have failed to get 15-0-15 5A TRANSFORMER and am thinking of using 15-0-15 3A transformer. in this case what will be the output in volts of the power supply, what about the output of the amplifier in watts,and what will be the magnitude of the audio input.please we have only 3A transformer and less in the electronics shops of our city and thats why i have choosen now 15-0-15 3A transformer thanks, your reply will be appreciated

  • Mike says:

    so i could just slap 5 9volts on this bad boy just to see if the circuit works aye?

  • ALELE MOSES says:

    Thanks alot mr seetharman.i tried looking for the 15-0-15 5A transformer but i didnt find it in the all of our city but instead i found 15-10-15 3A transformer and our laboratory technician advised me to use it and determine what it will give at the output of the power supply and my question is what will be the output voltage of the power supply if i use 15-0-15 3A TRANSFORMER, what will be the output of the amplifier,and what should be the magnitude of the audio input,will there be any adjustment in the other components like the bridge rectifier and other components in the amplifier.thanks your respond will be appreciated sir and i hope i will learn alot from this project.

  • ALELE MOSES says:

    am going to look for 15-0-15 5A transformer but can i use 6A10 diodes in the rectifier circuit instead of 6A5 thanks.what other alternatives are there for 0.33 ohms 7W resistor coz i dont have them in our electronics shops.

    • Seetharaman says:

      Hi Moses 6A5 is 6Amps 500Volt PIV rectifier. 6A10 is 6Amps 1000Volt PIV rectifier. you can use. In place of 0.33 ohms you can use 0.47 or 0.5 ohms 5watt if both are not available use two nos 1 ohm 2 watt in parallel. you please send me your mail to seethasub@hotmail.com

  • ALELE MOSES says:

    thanks alot mr seetharman for your wonderful work i want to use acombined bass cut and treble out filter please advise me about the connections and if possible send me the details on my email including how to connect it and the circuit including my new circuit and again am having problem of getting a transformer for the power supply am in uganda and today i checked all the electronics shops in our city but i didnt get transformer 30-0-30 5A, i got only maximum of 18-0-18 3A i didnt get 0.33ohms resistior for amplifier but all other components were there except diodes for the power supply instead a got 6A10 and i wanted to use it instead.please advise me about the possible adjustments and if possible the circuit diagram on my email coz i dont want to give up for this amplifier.i also have a maximum of 12-0-12volts power supply in our laboratory and i prefered it instead of assembliong anew power supply please advise me about the possible adjustment for this power supply and the circuit diagram of the adjustment.thanks

    • Seetharaman says:

      If you can get 15-0-15 volt 5 amp transformer can be used as voltage doubler circuit to feed +40 & -40 volts to amplifier. You can use the dual supply indicated in the following link. That can be adopted for any voltage.
      http://www.eleccircuit.com/basic-dual-dc-power-supply-6v/

      You can use the passive tone control using TL072 appeared earlier in Circuits today can be used with the above amplifier

  • Sudheer says:

    Interesting concept. Can you tell me where is it mainly useful? I mean in which cases we can frequently use this?

  • Alele moses says:

    i wanted to put this circuit into another use.please help me about this and may be how to connect it for another use.

  • rakesh says:

    will it maintain clearity like hi-fi systems,
    plzz reply am thinking to go for dis

  • moses akwenya says:

    these circuit schematics are very good for electrical/electronics/computer/telecommunications engineering students

  • bhaskar says:

    Hi, i want to use this 150 watt amp or your 100 watt sub woofer amp circuit for my car. is it possible. how to convert 12v DC to 36v/45v DC. pls help. if possible send via email. thanx

  • ASHISH KUMAR says:

    HELLO SIR,
    MY DVD PLAYER HAS SUBWOOFER OUTPUT, SO IS A SUBWOOFER FILTER NECESSARY?
    OR MAY I USE A BASS KIT AFTER SUBWOOFER OUT PUT AND BEFORE INPUT TO THIS AMPLIFIER. AND FROM WHERE I CAN PURCHASE THIS PCB? CAN U PROVIDE ME THIS PCB? THANKS

  • raymart says:

    helow. good to u sir.
    this kind of circuit amplifier, will it work in astereo circuit??

  • Neeraj verma.. says:

    Plz sir if you have a 12 audio stereo amplifire circuit then plz give me..

  • Jonathan says:

    Pls sir can dis cct be used as a subwoofer amp? if yes den how…?

    • Seetharaman says:

      Hi you can use this amp as subwoofer amplifier. feed audio input to the amplifier through the sub woofer filter, appeared earlier as a project in circuitstoday.(sub woofer frequency will be in the range of 80 to 120Hz).

  • Evans says:

    I have try this circuit and it works effectively.

  • Soumadeep Saha says:

    We made the whole circuit.. And did the modifications as suggested in the link… http://pcb.jspayne.com/150wattamp.html But even with or without the modifications it is not working… We are getting 40 volts DC at the output of the amplifier… What do you suggest … And how do I check to see if the TIP 142 and TIP 147 is working… Please help!!!

  • youngest C says:

    Pls sir does the circuit need a heatsink?

    • omer says:

      yes the two power transistors TIP 142 / 147 need a proper heat sink…

      TIP 41 does’nt need it

      • youngest C says:

        I used a 450watts-8 ohms speaker bt it rather got blown out. pls wat is the problem?

        • Omer says:

          hi youngest C ……
          We have built this circuit about more than 1000 times this works well and perfect..
          If you are facing any type of problems regarding this circuit then you can contact us any time….. we are here for your assistance

          We have a complete tutorial ( images as well as videos ) of this circuit’s building procedure…

          If you are realy willing to built this circuit with perfection then contact us below given mail…. we are here to solve your problems… thanks , have a good day

    • Ofcourse u need to use passive heatsinks b’se thoz are high power transistors

  • youngest C says:

    Pls sir, its just 1 output of the amp, what abt d other speaker? tanks

    • Omer says:

      hi ……
      We have built this circuit about more than 1000 times this works well and perfect..
      If you are facing any type of problems regarding this circuit then you can contact us any time….. we are here for your assistance

      We have a complete tutorial ( images as well as videos ) of this circuit’s building procedure…

      If you are realy willing to built this circuit with perfection then contact us below given mail…. we are here to solve your problems… thanks , have a good day

  • youngest C says:

    Pls, need a pcb layout for 150w amp

  • Seetharaman says:

    Use the following link and use the pcb design. you can also incorporate the improvements shown to the circuit, which are useful and also incorporated in the PCB.
    http://pcb.jspayne.com/150wattamp.html

  • Peter says:

    sir pls share PCB lay out and the analysis of this circuit 150 watts.

  • Soumadeep Saha says:

    The 33 ohm resistance in the circuit where -45 volts is applied is burning out and glowing red hot… What seems to be the problem…

    • Seetharaman says:

      Hi Saha It looks like your TIP142 is dead short. Kindly do a cold check of TIP142 between collector and emitter. Anyway check all the connection ensure you start with a DC voltage of plus minus 30volt DC and an 8ohms speaker. If every thing is in order use 45 volt DC supply with 8 ohms speaker. Since this circuit doesn’t have output short circuit protection circuit built in, (as we have maintain least component count)hence use 3amp fast blow fuse initially in positive and negative dc supply line to protect the output transistors. Once the system is healthy replace the fuses with 5amps.

      • Soumadeep Saha says:

        Thank but there seems to be another problem… I was using another pre amplifier with this circuit and I accidentally opened the connection for negative feedback thus increasing gain and bursting the 100 uF cap…Since then I am getting a voltage from ground…(i.e ground is at a higher potential)

      • Soumadeep Saha says:

        And can you tell me a test to know if BC558 is fine and also can you suggest an alternative…

    • omer says:

      recheck the circuit if its on PCB …..

  • sagar says:

    Hello every one i have made this circuit it is eorking but the output of this amp is very low even when i onnected a 12″ 150 watt speaker with 30-0-30 l5 amp transformer so could any one tell me how should i get full 150 watt output frm my speaker plzzz

    • sagar says:

      sorry in the above comment i have typed 15 amp transformer but it is only a 5 amp transformer sorry for my bad typing

    • Seetharaman says:

      Hi Sagar what is the impedance of the speaker. it should be 4 ohms with 30volt supply to get 150 watts. input signal to the amplifier should be at least 600mV rms (line level) if it is less add a simple 10 gain pre-amplifier between source and the amplifier.

    • Omer says:

      hi ……
      We have built this circuit about more than 1000 times this works well and perfect..
      If you are facing any type of problems regarding this circuit then you can contact us any time….. we are here for your assistance

      We have a complete tutorial ( images as well as videos ) of this circuit’s building procedure…

      If you are realy willing to built this circuit with perfection then contact us below given mail…. we are here to solve your problems… thanks , have a good day

  • kobena says:

    i tried this 150w amp the first time with tip 142,147 and 41c it worked well but it is over heating.however i discovered that tip 41 and 41c are different in value so i am working on that now.

  • atiqmohmand says:

    thinks its vry nice and helpfull circukts

  • Ricochet says:

    Is this circuit gonna work even the other components here http://pcb.jspayne.com/150wattamp.html are not placed? Thanks in advance!

  • i also want to know if it can work even if the supply is less than 40. tnx

  • sir , i just want to ask if this circuit can amplify inputs coming form mp3. and if this is mono-channeled
    tnx

  • ram raj says:

    HI NEED TV CIRCUIT

  • CHANDRASHEKAR says:

    Sir, Assembled the circuit for 150w power amp,it did not work.we are getting only humming noise. Initially DC supply connected was 17V dc dual supply for try out.is it necessary that max volt to be connected.what may be the reason,out put base voltage is max(13v) on both 142 &147 power transistors.would you kindly let me know the reason also please forward ref.voltages.
    Regards kindly reply\Chandrashekar

  • Ismael Issah says:

    Thanks to u guys for the education. l want to try my hands on this Amp (150 W) and want to ask, does TIP141 transistor the same as the TIP142 transistor in this circuit? And therfore can l replace TIP142 with TIP141?

  • iddy fadhily says:

    plias tell me nomber transistor sacet 207

  • iddy fadhily says:

    pls mr i need to sarcet diagram sherwood amplifer model no ra-11114t prias help

  • omer says:

    hi can any one tell me that if i use this amplifier with 4ohm load then ???

    • rohin says:

      hi, this amp cannot support the 4 ohm load because it has only two transistor at output.it will overheat on 4 ohm load and will burn.at low bass it will be ok.

  • Christian says:

    First of all, sorry if this is a stupid question. But I’m total newbie on audio amplifiers! With that said, now to the question:

    I have a couple IRFR2497, can I use this layout and replace Q1 to Q5 with those? I understand that I might need to have different values on resistors and such.

    Kind Regards
    Christian

  • Soumadeep Saha says:

    i would like to know the wattage of the other resistors

  • Jyo says:

    please share the information related to digital storage oscilloscope….

  • omer says:

    https://www.facebook.com/auxtics

    see this amplifier working in stereo mode.

    sound is amazing and mirror cracking…

    Questions related to this design will be answered here. thnx

  • Vijay says:

    Hi Seetharaman,

    I’m planning to build this circuit. Since I’m going to make a stereo, I need to double the power rating of the transformer. I’m planning to order a 30-0-30 10 or 12A transformer. Could you please let me know if that will be enough? If that’s the case, more importantly, I would also like to know which diode I should use for the bridge rectifier. Can I use two P600A in parallel? what would be the voltage drop?

  • LENNY says:

    hi all, i have built this amp 7 times, each time i am left with an amp that has fail each time with +v rising to full psu volts the neg supply dies to 0v. the speaker 0 volts has half volts at this point. the – supply falls to zero. the npn o/p device has on, 3 times blown its guts out. i found a circuit by vellman 100w 200wmp kit and noticed that the 150w amp is a stripped down version of the 150w one. i am a electronic design engineer in the u.k. and notice that using a scope i have found that this design is as stable as a brick in custard, sorry guys, but with all the mistakes in and on the circuit it shoud have been fully noted with corrections and fully tested BEFORE it was issued to the net. i have never found a circuit to SO DODGIE. and released to the public.
    Unless someone can save this amp from distruction each time i conect it to a power supply i would all avvid builders to not to bother with this design. i have used a power supply (dual) +/- 2v to 100v this amp has failed at +/- 15v @6a and it still blow up ? my fear is regardless of layout(s) and i have tried 4 different methods and layouts including one from the original pictures AND IT STILL BLOWS UP?
    THANKS TO ALL FOR READING THIS AND IF THERE IS A CURE FOR IT PLEASE LET ME KNOW

  • Hallotje says:

    can i use a 30-0-30 v 8amps trafo for a stereo amplifier?

  • sina says:

    Hi, I’m here to find transistor tip 147!
    The type of transistor, the transistor, which is the same.
    I am Iran
    Two’m Goodbye
    This is just a quick answer.
    **
    Similar tip147 transistor is?

  • prudencio g.peritos jr. says:

    I had been adding BD 139 and 140 to my second amplifier with TIP 2955 and TIP 3055 AND ITS WORKING GREAT when i convert to stereo its working great,thank you for this site,I learned and gained more knowledge about amplifier…

  • dioniz edward says:

    can i have the data analysis of the circuit because my friend asked me why did i use BC 558 and not other kind of transistor i didn’t find an answer can you help please?

    • rohin says:

      you can use other transistor but this is good and cheap.if your friend is intelligent then you can ask to him for other transistor.

  • neimat says:

    Dear sir,I did ​​this ampli but I have a problem, that in the entrance of audio I have a wave signal (12V, f = 1Hz), but I obteint in the output of the amplifier square signal ? why? it’s logic? please advice

  • prudencio g. peritos jr. says:

    Atlast i had been enjoy my amplifier using BDW 83c and 84c with Passive Baxandall Tone control its working great. Now i assembled another amplifier using TIP 3055 and TIP 2955 its working great also,,,and i plan to add another transistor using BD 140 and BD 139.,,hoping it will work soon

    • sagar says:

      well hello Mr.prudencio g. peritos jr could you post your amp ckt video plzz , i have done this amp ckt but it’s output sound is very low could you plzz guide me( i have used 30-0-30 ,5 amp transformer also but it’s output is less)

  • soumen says:

    i want high bass audio circuit board.

  • ermsk8er says:

    Hello again! My TIP41 is overheating and suddenly my R10 (33 ohm) fried/busted. Please help me. :( tnx!

  • rohin says:

    hi to everyone,For pcb of this nice amplifier is available. http://pcb.jspayne.com/150wattamp.html.Don't use update version.

  • ermsk8er says:

    Can i use 1 heatsink to transistors; tip41, tip142 and tip147?

  • Julius says:

    sir robin just a little bit correction to my email add and this regards with the PCB of the 150 watt power amplifier circuit i am asking to please send me a layout, thank u & more power
    jsl_7458@yahoo.com

  • Julius says:

    12 December 2010 at 1240H
    a very nice circuit and thank u so much for sharing! by the way sir robin can u pls share me a PCB layout of the 150 Watt amplifier circuit. Thank and please, more power and GOD Bless…

  • jay says:

    sir pls share PCB lay out and the analysis of this circuit 150 watts,., nusoncar@yahoo.com

  • ermsk8er says:

    Nice one circuit, thanks for sharing it! By the way cAn anyone send me the pcB layout for this circuit.. Thanks again.! God bless!
    My email – erm.sk8er@yahoo.com

  • Terry says:

    Im having a hard time looking for a 120V to 30V step down transformer for this circuit. Can somone please tell me where I can find these components? Post or send a link if possible please

  • nitin khandelwal says:

    what is the basics theory to design such type of circuit?how shall we start to think to built such circuit if we beginer of electronics?…which comp. is required or not?..how can we justify which comp. is connected at perticular place.if i use 4 darlington then what happen if any link there to know about these plz tell me.

  • AKANINYENE IKOEDEM ESSIEN says:

    pls sir i need a circuit diagram of audio receive,

  • harssh says:

    hello Mr. Seetharaman
    well i have gone through your circuit and its quiet intresting so i have done it on a pcb but it aint working so could you help me how to check it or what to do plz….

  • jagadeesan says:

    Hello Seetharaman sir!
    it very interesting working on this circuit.
    Sir i have used 32v-0-32v 8amps transformer for this circuit you have mentioned to use 30v-0-30 3amps transformer but i am using 8amps wil it create any problem?
    and in this circuit the output terminals from pcb is having 46v when checked with voltmeter when checked with no input,

  • Prudencio G. Peritos Jr. says:

    thanx bro i sent you an email with the link which i got the PCB layout,,,hoping your reply soon with you suggestion or advise

  • Prudencio G. Peritos Jr. says:

    You are right Rohin,,when i checked the output with the tester ,i put it at 250 volts,,and i found out that there’s a voltage came out…that,s why the music is not clear…I add some 2 resistors and now the diction is clear alredy..i used 16 sqr inch heatsink because the Q1 is so hot,but the Q2 and Q3 is normal,..can you suggest me regarding this problem, please,.
    I used TURKISH PCB Layout,,,using BDW83C and 84C,,with TIP 41 and BC556…with POWER supply of 24-0-24v,6A…Please suggest me regarding the Q1 is so hot…Longing you reply soon.

    • rohin says:

      hi bro, as you said that there is some volt on output so there is some fault in you design. you used good alternative transistor so problem is not due to alternatives transistor.if your q1 is going hot n hot it will blow after some hour.first wash it with thinner then check polarity of all capacitor and good look at ground pin.you please give me link of pcb layout and component list that you used in your circuit because my guess is that you didn’t wrong anything problem due to any wrong component and wrong value resistance.my email id is rohin.sharma83@yahoo.com.

  • Prudencio G. Peritos Jr. says:

    Thanks rohin ill check it…and you will know further

  • S.alam says:

    can any one please send me pcb layout of this circuit
    at
    alamisdecent@gmail.com

  • Prudencio G. Peritos Jr. says:

    Sir, i have done already assembled this amplifier, using BDW83c and 84c, it is very loud but the diction or wording of the music is not clear..and Q1 is very hot even I am using 3″ x 3″ heatsink…please help me, what shall I do regarding my amplifier..
    Hoping your reply soon. Thanx.

    • rohin says:

      dear bro ,i already made this amp. amplifier is beautiful and clear sound and loud too.it seems that there is something wrong in your amp. R2 should be 220 ohm.if everything is fine then problem is due to alternative transistor.and made this amp as it is.don,t use its updated version where some one put more components like pf and resistance. check the output of amp with multimeter put the scale to dc 200v plus and it should be zero.if there is some volt then you did something wrong.

  • S.alam says:

    hello sir i have build this amplifeier with 24v &1amp transformer and there is too much distortion i use speakers of 35 watt 6ohm
    please answer what should i do?

  • miloh says:

    sir why does the sound not amplified?? i change all the transistors that i use. what should i do???

    • rohin says:

      if you made it on pcb then pcb may be short one track to another or your flux is not removed on pcb .wash it with thinner or if you made this amp with additional component like pf and resistance then remove them.their is minor fault in your circuit or you fit wrong way any component.

  • ALams says:

    hi sir
    can you please tell me how to convert this amplifier into stereo?

  • Prudencio G. Peritos Jr. says:

    hello sir,
    what transistor can i replace TIP 142 and TIP 147?can i replace also

    TIP 41? for matching Q1, Q2 and Q3

  • normzhie says:

    i used 45v vdc and i have a pre amplifier connected in a 150 watts amplifier. then i try, the circuit is good and theirs no problem on it . but i confused i try to volume at 50% with a load at input at no power then i turn on the fused blow out together wid tip 142,147 whats the problem on it sir?

  • chhotu says:

    HI sir i have a 142 & 147 with amplifier,when i playing this its too hot.can i chenge 142 & 147 to tv’s power horizental transisters like sd1410,sd1550.Please reply.

    • Dissanayake says:

      TVH-out is not a darlington transistor and it is low current and high voltage drive transistor. You have to try with larger heat sync and cooling fan can apply. in other hand you have to replace 142 & 147 only with darlington types.

    • Seetharaman says:

      Hi Chhotu The power is RMS voltage available across speaker terminal, V square / speaker impedance. It is clear that for higher power you have to raise the voltage or reduce the speaker impedance. your heating up may be due to higher no signal current for the output transistors, chech the D1 and D2 loop.

  • ashish says:

    sir please tell me how you decide the output power as here you have said its cheapest 150 watt amplifier circuit.

    • Dissanayake says:

      Basically output power is depending on the supply voltage and impedance of the speaker. P(out) = sqr(V-10)/R.
      V: supply voltage (45v)
      R: impedance of the speaker (8Ohms)
      here 10 is the voltage drop by the darlington.

      you can increase the output power by reducing the R or 10.V
      to reduce the 10V drop you can apply more output darlington in parallely with 0.33/7W resistors.

  • Boogie says:

    Good day sir, I built 3 of this wonderful amp without any problem, except for the “excessive heat” of the Darlington pair. I used a fin type 3″x5″ heatsink for each transistor. I know I can use a bigger heatsink but my question is, what causes the Darlington pair to “overheat”.
    Pls. reply to my e-mail…..

    Thanks and more power…

  • prithvi says:

    sir i have a 44v-0-44v 5a tranformer . After using capacitor 60v-0-60v is available ,i can use this circuit for this psu?

    • hey prithvi, go ahead do not worry about supply. you can use this t/r. but take care that you have to use filer condencer of 75 workig volt.do not forget it.it is better to use instead of 63 woring volt cond.and one more thing ,use 33 ohm one watt resistences as a current limiting resistences to connect positive and negative supply of an amplifier.if you do not use these resistences then both the tr, tip 142 and tip 147 blown off in less than a second. because i have tested this amplifier today.it works well.

      • Dissanayake says:

        Manohara, applying 33 ohms resistors is not recommended. because the power amplifier is consuming variable current while it is working. so voltage drop across the 33 ohms is variable. Think the amplifier consuming about 1Amp current. so voltage drop across the 33 ohms is (V=IR) 33Volts. the power supply is about 40V the voltage of the amplifier is about 10V. So this is not the right way. Prithvi, I recomended you to increased voltage of all the capacitors up to 70 volts or more. and Vce of all the darlington transistors should be at-least 80V. Vce of all the other transistors should be at-least 120V.

      • prithvi says:

        thank you for reply .i was waiting for the reply for 3 days after that i tried it from 32vac to 56vac(45vdc-79vdc) from a 550va 8 kg transformer and i used 4 transistor per channel, my two 120mm 8” speaker’s blown . But transistors are fine ,this amp pays back every thing with less hifi quality.

    • Seetharaman says:

      Hi prithvi all the transistors may blow up. Never use higher than 30 – 0 – 30 Volt RMS @ 3 amps transformer.

      • prithvi says:

        sir i have asked tis que. bcos i have spent time and inr 2k for making 44-0-44 5a with auxilarary winding 12v 2a transformer . I have used parallel 142 and 147 with no problem or blowing of transistor and i used bc 556 for pre amp.

  • rey? says:

    sir? if rectifier diode in the power supply is 6A05. its okay sir? tnx sir and God bless always^^

  • Joseph says:

    Hi samshith,in reply to your request.I am happy to announce to you that i can give you all necessary information you need on this amplifier circuit and other audio system information.I am the MD/CEO of my own electronic fabrication centre,I have trained alot of people and also written some book on sound system and electrical gadget.Should you are interested contact me via my email.

    • statement: design an audio systm f a fitnes clb f an area 700 sq.feet with glass windows and conseald sealing with following specifications
      instruction mikes,cd/dvd player,appropriate signal conditioning ckt,suitable pre and power amplifier ,7 band grafic equalizer,volume control,tone control,sound level indicator,distortion cancelling ckt,power supply with sht ckt protection and power on indicator,speaker should be column and sealing ,mixed arrangement.

      drawings:
      amplifier enclosure ,half schematic ,sample drawing of sealing and column speaker,connection diagram….

      please let us no it………..by tomorrow….it’s very urgent sir………..help us….it very urgent……….

  • prudencio g. peritos jr, says:

    sir, as per power supply diagram c1 and c2 is 4700uf,,,c3 and c4 is 100nf,,,100nf is no available in our market,,,what capacitor shall we replace this 100nf capacitor? please confirm…thanx

    • Dissanayake says:

      the minimum of C1 and C2 should be 4700uf electrolytic and c3 and c4 should be around 100nf and should be in Mylar type. (68oouf, 10000uf also better for steady current).

      c3 & c4 are acting as high-pass filter and reducing high frequency oscillations in the power supply. any value between 0.1uf (100nf) and 0.22uf (220nf) are ok for c3 & c4 (both c3 & c4 should be same)

  • prudencio g. peritos jr, says:

    hi sir, 30-0-30 volts is not available in our market, can i used 24-0-24 volts transformer 6A ?,,thanx

  • Prudencio G. Peritos Jr. says:

    Sir, thank you so much for answering my comments… Have a nice day,,,God bless you

  • Ljay says:

    Hello sir Seetharaman, I’m from Philippines, Manila I would like to ask if what speaker should I provide building this amplifier using all same active and passive components except that I’m only using 4Amp 30 – 0 – 30 transformer.

    I’ve just build this right this morning and it seems working fine without smoke appears only that I don’t have a speakers yet. I’m a Student!

    Thank You Sir!

    • Seetharaman says:

      Hi Ljay. You can use 100watts 8 Ohms 12″ full range speaker, in an air tight 65 litres inner capacity enclosure.
      Hi Ray use 6A10 to be on the safer side.

    • Dissanayake says:

      I tried this circuit with several darlingtons and three way speaker system. also I applied integrated speaker protection circuit to the output of the amplifier. it is recommended to transistor amplifiers because to protect the valuable speakers. the amplifier has very good low frequency (bass) response and it is recommended to apply good low pass filter at the input of the amplifier was trying to oscillating at high frequencies. I thing it is good to apply two way or three way speaker system with good bass woofer rather than a full range speaker. you can also apply a good cross-over circuit for hi-quality music response.

  • Seetharaman says:

    Hi Prudencio By keeping the flat surface dowm and ensuring that the pins are pointing to you. Left side pin is emitter center top is base and right is collector.

  • isaac says:

    i’m olso interested on constructions of amplifier circuit, but i dont have enough basic obout transistors. i’m doing electronic 2 in computer system engineering. so can you please help me to find more information by sending me some simple circuits to construct.

  • Togor says:

    The designed is ok d output power is recommented.the heating effect is mush as power suply increases what could be done to use circuit at +70 & -70volt look forward to hear from you.mail me dialinton power transistor that can withstand 80volt

    • Joseph says:

      Hi Togor,concerning your request contact me via my email.I promise to give you better power darlington transistor that can withstand 100 volt and 45 amp.Am MD/CEO of BODNIK TECHNOLOGIE VENTURE here in Nigeria.And i specialised on sound system fabrication.

  • prudencio g. peritos jr, says:

    sir, can you give the pin out of this transistor BC 558,the store did not give the pin out,,,im beginner,,,thanx

    • PRUDENCIO,YOU PIC THE TRANSISTER BC 558 ,UP SIDE THE CASE AND FLAT SIDE OF T/R IN FRONT OF YOU & LOWER THE SIDE THE PIN OF T/R, THEN THE RIGHT PIN IS EMMITER,THE CENTRE IS BASE AND THE LEFT ONE IS COLLECTOR.

  • Pankaj says:

    thanks sir……

  • Seetharaman says:

    Hi Pankaj 12″ 150 watts woofer is best suited in an air tight enclosure, with an internal volume of 45 to 60litres.

  • mustafa kuşcu says:

    süpperrrrrrrrrrr power supply

  • Pankaj says:

    sir can I use a 12inch 150 watt sub-woofer driver with this circuit?????

  • Pankaj says:

    Thanks a lot sir for your support and help.

  • Seetharaman says:

    Hi Samshith 63 volts or higher.
    Hi Pankaj why not? you can use with the sub woofer filter appeared earlier in circuits today
    http://www.circuitstoday.com/low-pass-filter-for-subwoofer

  • Bert says:

    Hi sir if i build this amplifier in two channel it will work or not? Plz reply..,

    bert from mindanao, philippines..


    Via MebApp.com

  • samshith triprayar says:

    sir, i would like to made it. So help me. I want to know capasitor4700uf volt?

  • Deogratia says:

    Dear Sir.
    i am happy to get in contact with you, please i need your help concerning this amplifier, When i assemble the amplifier in Mono, it works well, but when i make it stereo, the left channel or right channel will not work, i inter changed all parts from left to right, one chanel still maintain this fault, Please what can be the solution to this? do i need to assemble a split power supply using the same transformer or two transformers for this amplifier, then my second question is that, can i bridge this amplifier to Mono to get more power out-put that can drive my 4 pieces of 21Inches speakers for commercial use? please my email address is(dnkwenti@gmail.com) any help from members here would be appreciated, i am happy to share with good hearth people.
    Thanks

  • Pankaj says:

    sir please help me I want to use this circuit for subwoofer how can I use it??????
    Can I use a low pass filter??????
    if yes then please provide me the circuit diagram….

  • Seetharaman says:

    Hi Spharow with 24-0-24 transformer with 8 ohms speaker the output power will be around 60 watts. You require an input of not less than a signal level of 250 mV. Use a pre amplifier with a gain of 10 to 25.

  • Spharow says:

    But having this 24V 0V 24V is not loud enough for me to play my e.guitar?what’s the power of the speaker do I need to use?Or do I need to put preamp before it,plz repz…

  • Spharow says:

    Thank you so much, I already found out the fault. The positive line of the of the speaker is shorted unto the ground..tanx..:)

  • Joerz says:

    Hi sir, good day.
    If I build this amplifier in stereo it will work or not?
    please reply.
    thank you.


    Via MebApp.com

  • Benson githaiga says:

    Hi Sir its my desire to work on this circuit very soon,please send me this page in my email to facilitate my study and reference as i work on the project.thanks God bless

  • joe says:

    I have done this schamatic but went i combint the p.supply on power Ac…the
    Power ampl. Have sound sudenly for a second sound stop…just hear the voice tottt………

  • isaac hlengani says:

    Thanks for the good work,
    Thats very powerful amplifier.
    I’l try to construct it coz it is visible and understandable,
    God bless you keep it up to assist us as student.

  • alvin says:

    hi! sir, can i ask? what is the wattage value of all the resistor and the voltage rating of all the capacitor’s?

  • Seetharaman says:

    Hi Ramdas I have sent the email it had returned. send your letter to my email id seethasub@hotmail.com

  • ramdas says:

    Dear Br. Seetharaman…I have 2 requests
    1)I want to assemble this 150W amplifier (TIP142/147)..But from where I can get the PCB layout or readymade PCB kit…
    2)Can u please sent me ur email address..cause I have one old Tone control PCB by Visha electronics..of the circuit published in Elektor India.long back..i think in 80s.I dont have the circuit diagram..if i have ur email address I can attach the photograph of the same for ur kind perusal…I tried a lot for this..pls help me out..
    With hope..
    Ramdas.(n.ramdas@yahoomail.com)

  • seetharaman says:

    Hi Anbu please go through the following link
    http://pcb.jspayne.com/150wattamp.html

  • Anbu says:

    how to assemling this cuit

  • Tosin says:

    Thats very kind of you sir, you’ve been a blessing to us.

  • Seetharaman says:

    Hi Tosin they are power Darlington transistors with freewheeling diodes and currnt limitting resistors. You can fabricate then by using TIP2955/ TIP3055 matched pair (Any High Voltage high power)output transistors with BD140/BD139 (any high voltage medium power)with IN5404 or IN5819 as freewheeling diodes .

  • Tosin says:

    I want to know if there are other transistors which can replace tip142, tip147 in the diagram because these ones are not available in my area now. Thanks for the good work

  • Seetharaman says:

    Hi John you can use 10KuF 63 volts in each supply line. (both positive and negative voltage). You can always use a higher power amplifier with a little lower power handling capacity speakers, nothing will happen. The other way, the distortion generated by the lower power amplifier can damage the voice coil of the higher power speakers.

  • prudencio g. peritos jr, says:

    thanx a lot sir,,,MAY GOD BLESS U

  • john says:

    is it ok if i used a 80 watts amplifier to 150-200watts speaker ??? thanks

  • john says:

    can we use a 10k uf 63 volts capacitor in the power supply?

  • Seetharaman says:

    Hi Rusty TIP41 is NPN, which is required here. TIP42 is PNP with which you will blow the output transistors.

  • RUSTY HEARDER says:

    MADE PC BOARD AND ASSEMBLED IS Q3 A TIP41 OR A TIP42. WHEN SWITCHED ON
    3WITH 25V SUPPLY Q4 AND Q5 BLEW ANY IDEAS PLEASE.REGARDS RUSTY.

  • Seetharaman says:

    Hi John no need to use screws just slide on the clip.

  • john says:

    what is clip on ?
    thanks a lot bro ..

  • Seetharaman says:

    Hi John it is a must, for TIP142 & 147 you require a large extruded alloy heat sink. for TIP41 a clip on will do.

  • RUSTY HEARDER says:

    Good day , I have Query, Ive biult the 150watt amplifier but have a problem. In the write up it calls for a TIP42, but in the diagram it calls for a Tip31. when I connected up with Tip42 r4 burnt up including Q4 & Q5. on replacing them it burnt Q2 ,Q3 Q4,Q5 R10, c2.
    I had a30volt supply. could you throw some light on this.
    Regards Rusty. rhearder@intehom.co.za

  • john says:

    heatsink for the three TIP are needed??? please answer thanks

  • Seetharaman says:

    Hi Prudencia please refer my earlier comments on this
    December 15, 2011 at 9:46 am

  • prudencio g. peritos jr, says:

    hello sir. as per diagram Q1 is TIP 41? or TIP 141,,likewise the capacitors ,the volt was not given for every capacitor listed in diagram,,,

  • john says:

    heatsink is needed for tip142 tip147 and tip41 ??what kind of heatsink is it??
    Thanks seetharaman..
    Pinoy ako

  • Seetharaman says:

    Hi Many connect a 22k or higher value potentiometer for volume control. Connect one end to 0 volt line and the other end to input and potentiometer’s center pont(slider) to audio in of the amplifier.

  • GILBERT says:

    tnx seetharaman, i using for my mobile sound system big horn tweeter if you have more compatible amps for tweeter can i request more fabor.

    Tnx and more blessing to you and CT….

    Respectfully yours,
    GILBERT
    PHILIPPINENS

  • jjemmanu says:

    how are you to connect the variabel resistors to vary the volume

  • Seetharaman says:

    Hi Gilbert reduce C2 from 10uF to 1nF. Add a 47PF from Q3 collector to base. Why do you require so much for tweeter power?

  • GILBERT says:

    Sir Seetharaman
    A nice day, if I use for tweeter power amlifier this circuit what is the modification.
    Tnx alot Gilbert…

  • Seetharaman says:

    Hi John with low value potentiometer while it is set at extreme ends will get burnt, hence a fixed resistance is preferred.

  • john says:

    thanks seetharaman

    no potentiometer ?

  • Seetharaman says:

    Hi John you can use 3nos 1 ohm 2 watts (which is standard and freely available)resistance in parallel to get 0.33 ohms 6 watts.

  • john says:

    what if r8 and r9 is not available in the market ? what should be replacE ?thank !

    from the philippines PINOY !

  • Seetharaman says:

    Hi all capacitors should be 50volts or higher

  • john says:

    in this schamatic 150w ampl. the all capacitor did’t swo how much volt u can put?c1,c2,c3……including the power supply c1,c2,c3,c4…..all this capacitor did’t swo how much can put?pleeeseee…….imfom. me…this ergent!!t.Q…

    can i use 6A in transformer > the value of others will affect ? help me tnx

  • brian says:

    what is the voltage of 100nf ?? thanks …

  • brian says:

    what should be in AUDIO IN ?? beginner thanks

  • brian says:

    how many watts in R1 , r2 , r4, r6 , r7 and r10 ..thanks

  • panos says:

    seetharaman sory for asking you a lot of cuestions but i measured 75watts into 8 ohm load.if i use two pairs of tip14x conected in paralel i will take 150watts rms ito 8 ohms?thanks for your help!

  • denny says:

    thanks circuittoday, I’ll try to my project..

  • krishna says:

    Hello sir I am having some douts…….
    1. I am having a (24 w 4ohm)*2 speaker,is dis circuit suitable for powering it
    2. Normally in stereo circuit we hav 2 inputs (R&L)but in dis circuit i can find only one.. So do i hav to make 2 circuits for stereo output I.E (150w circuit * 2)?..

  • panos says:

    thank you seetharaman!

  • Seetharaman says:

    Hi Panos you can use any tone control which uses plus and minus supply similar to our Passive tone control, which is most suited for this project.
    http://www.circuitstoday.com/passive-tone-control-circuit

  • panos says:

    hi sir i made this circuit.its working grest!!can you sugest me a tone control circuit for this amp?

  • seetharaman says:

    Hi Rush you can use two capacitors in parallel. it will suit. you can use ceramic or polyester capacitor rated for 50volts or higher

  • Rush007 says:

    Hi sir,

    Plz suggest me about query posted on February 13, 2012 at 8:12 pm

    thanx a lot

  • Seetharaman says:

    Hi Spharow check the bias diodes D1 & D2 direction, the end with a white band is cathode.
    Have you insulated Q1 & Q2 from heat sink with proper mounting kit.

  • Spharow says:

    I’ve assembled it but the moment i run it, the wire from power supply(+) is melted and burn the wire..(0) is on the ground and (-) is on the collector of tip147..I’m just using 24v 0v 24v..what’s the problem?I’d rechecked it over and over again but the circuit is just rightly connected..

  • T0C says:

    Hi Tmaxx226,
    The 300VA transformer should do just fine for the stereo application, but I recommend using the 500VA instead, having a little more power than recommended is always better in amplifiers.

  • kole says:

    any circuit available which converts from 60 W audio o/p with 16 ohms res to 150 Watts 16 ohms.

  • Tmaxx226 says:

    seetharaman,

    Will a 300VA 30-0-30 toroid transformer produce enough power for a stereo application of the amplifier? Or would it be best to use a 500VA transformer? Thank you for the help!

  • Rush007 says:

    Hi Sir,

    I have done my 150W amp as per ur instructions and its working gr8.

    Sir, now i going for subwoofer low pass filter shown in http://www.circuitstoday.com/subwoofer-amplifier

    But, as per ur suggestion for 0.18uf(C1)we can use 0.1uf & 0.082uf in parallel. So,please let me know which type capacitor i can use for 0.082uf? Is it disc type?
    Thanks again…………. Have a nice day..Happy valentine day….

  • Rushal says:

    Hi Sir,

    I have done my 150Watt AMP as per your instructions and its working fine.

    Thanks for your help.

    I want to assemble subwoofer low pass filter shown in http://www.circuitstoday.com/subwoofer-amplifier
    But, i didn’t get 0.18Mf(C1)in market.So,
    As per your suggestion for 0.18Mf we can use 0.1Mf+0.082Mf.
    So, please let me know 0.082Mf is which type of capacitor? Is it disk?

  • seetharaman says:

    Hi Jam +45volt should get connected to TIP142 collector and -45volts sholud get connected to TIP147 collector. zero should be connected to terminals shown as earth. (speaker’s one end, C3, R7 and input common terminal)

  • jam says:

    hi sir, just wanna ask.. on the circuit proper, where should we connect all of the ground? and also, should the -45V be connected with the grounds as well? pls reply. thanks.

  • T0C says:

    One last (possibly stupid) question.
    I’m making it with 2n3055/MJ2955 darlingrons. Their rated power is 116W 60V 15A, the rating of the TIP147/142 is 100V 10A 125W, so will there be any drop in the output or will it increase/remain the same (my guess is drop)? Or will the output impedance handling change? (Will be used as a driver for a sub, the sub is 250W rms 4 ohm). I’ll be using a 45-0-45 ~10A supply.
    Thanks in advance.

  • Boogie says:

    I assembled two units for stereo but every time i test it, one unit blows!!! I tried to separate their power supply but still the same…( I already busted 10 pairs of TIP142 and TIP147) I continued troubleshooting but I can’t find any defect in the circuit,The latest part replacement of the Darlington pairs were OK, I guess I must have bought fakes TIP 142 & 147….
    The sound is good. I used this this Ckt. to drive my Subs and center speakers….. I’ll send some pictures later….

  • seetharaman says:

    Hi Rush the PCB shown is perfect the layout is also correct you can go ahead.
    Hi Panos the maximum output with +42-0–42volts DC can produce 200watts into 4 ohms load.
    Hi Noel 4700uF can be 63volts DC or more. C1 & C2 & C3 can be 25 volts
    HiToC use 2N3055 MJ2955 with BD139 and BD140 as darlington.

  • noel says:

    1. can’t u give the condenser What volt in use=4700uf ?v
    =C1,C2=10uf ?v
    =C3=100uf ?v
    2. the transformer 5A can use more then 5amphere?

  • T0C says:

    Will this work, because i’m too lazy to go out and buy the TIP142,147 now, won’t making it with 2n3055(I know 2n3055 is not darlington but I’ve added another transistor to make it like that also without the other transistor it will work too) darlington do it? (of course 2n3055 with MJ2955)

  • panos says:

    hi ser,i am panos from greece and i want you to tell me the maximum rms watage i can take of this amplifier.

  • samshith triprayar says:

    hi sir,
    i try this amp. I’am very sad this is not woking.
    D1 and D2 and R5and R3 is very very hot

  • jambebe says:

    sir .. for this circuit that you posted is it necessary or do we need to add an preamplifier ? if yes how ? thanks

  • Rush007 says:

    Sir….. If i using +/- 50 volt DC power supply its need to be change R6 value??

  • normzhie says:

    sir can i connect another pair of tip142 and 147 in a parallel connection. what will happen the rms will be increases? thanks

  • Rush007 says:

    Thanks a lot Sir

    can i refer below mentioned URL.

    http://www.diyaudiotr.com/islecler/tammetin.php?metinid=6&durum=e#sonyorum

    Thanks again & sorry for continues asking questions to you……

  • seetharaman says:

    Hi Rush007 TIP142/147 pair output is limited to 150watts maximum into 4ohms load with +35 0 -35 volts DC and around 100watts into 8 ohms load with +42 0 -42 volts DC.
    BDW83C/84C 150watts into 8 ohms with +52 0 -52 volts DC and 250watts with +48 0 -48 volt DC.
    Since peak current is going to be quite high layout and the gauge of wire used are very important. Please take care.

  • Rush007 says:

    Sir….. actually i want 150Watt RMS(on 8Ohm)& 300Watt RMS(on 4Ohm).
    can i get this by using BDW83C / 84C pair.

  • Rush007 says:

    Sir…How many RMS output can i get from this circuit for 4Ohm/8Ohm woofer with using BDW83C / 84C pair instead of TIP142/147 pair which suggested by you. Have A Nice Day.

  • Rush007 says:

    Thanks a Lot sir………Ur Gr8.

  • Seetharaman says:

    Hi Rush007 no need for any other modifications, just replace the output transistors with a good heat sink.

  • Rush007 says:

    Thanks very much Sir………but let me know what changes needs to do in original 150W circuit with BDW83C / 84C. Have a nice Day……

  • seetharaman says:

    Hi Rush007 you have to use >150 watts amplifier for good transient with 150Watts speaker (always use an amplifier with a speaker with less capability, with higher capacity speakers the amp distortion will be transferred to speaker and damage it) . Use DC 50-0-50volt 3amp power supply and use BDW83C / 84C pair for the output, with good large heat sink.
    you can use the sub woofer filter appeared in our projects
    http://www.circuitstoday.com/subwoofer-amplifier
    No PCB layout available you may use standard universal boards.

  • Rush007 says:

    Thanks for response sir…..Request to you please give me suitable sub-woofer filter or sub-woofer output pre-amp circuit diagram for this 150 watt Amp.

    And sir what is the recommended sub-woofer and DC +/- Volt for this 150 Watt circuit because my requirement is to use 12″-150W-8Ohm Sub-woofer.

    Thanks Again sir….. And Wish u Happy New Year.

  • seetharaman says:

    Hi Basi +40-0–40 volt DC not AC. AC 30-0-30volts
    Hi Rush007 you can use with a suitable sub woofer filter or the sub woofer output of pre-amp / amplifier

  • Rush007 says:

    Sir, Can i use this AMP for my sub-woofer(12″-150W-8Ohm)

    Please suggest me..Thanks.

  • BASI says:

    Hai seetharaman..
    Plz help me..
    I have used irf250 4 mosft pwr amp volt why..?

  • BASI says:

    Hai
    40 0 40 AC volt
    DC ???

  • Bryan Laroya says:

    thank you sir seetharaman……….,i will do your advise…

  • normzhie says:

    hi, sir thanks. the circuit was great. but if you use 8ohms speaker the output of 150watts rms, it become 75watts rms. in mono. thank you sir you are great.. if you have a 1000 watts rms pls send me thans hers my email normzhie@yahoo.com

  • Malik Umair Latif says:

    Specify the speaker, How much inches?

  • somnath says:

    Power full Amp-
    thanq!

  • seetharaman says:

    Hi Bose you require smaller clip on heat sink for Q3, and extruded alloy heat sink of around 16sq inches for output transistors Q1 & Q2.

  • gsripon says:

    this is helpful

  • Bose says:

    sir is heat sink required for the transistors ?

  • Bose says:

    thanks seetharaman

  • seetharaman says:

    Hi Bose you can use 0.47 ohms 5watts resistance. for 4 ohms speaker better use 0.33 ohms, this can be achieved by using 3nos 1 ohm 2 watt resistances in parallel.

  • Bose says:

    sir i dnt get the resister 0.33 ohm what can i do ,can any other resister is enough or else .33 ohms is required
    thank u,

  • Seetharaman says:

    Hi Bryan it is working great. please go through all my comments. Q3 should be TIP41 NPN transistor.

  • Goutham says:

    Oops, finally it was working awesome….
    But there was huge distortion when connected (just connected but not played any music ) to the computer output directly without a pot.
    Is it normal with this Amp or is there any mistake in my construction. I have used 10000uF caps as filters.

  • Goutham says:

    And I was also tried with 24-0-24 transformer, but the problem still exists.

  • Goutham says:

    Hello sir,
    I have built this circuit, but when I have checked the output voltage it was displaying around 110 volts at 0 input signal btw I was running on 40-0-40 transformer. when I have connected my subwoofer the diaphragm coming out from its neutral position and stays over there until I turned off the power supply.
    I have rechecked the circuit many times every thing was ok, and replaced all transistors, but the problem still exists.
    Any idea on this.?

  • bryan laroya says:

    sir can you clarify the Q3?….cause in diagram its TIP41 but in the description above its TIP42!…thats all sir!!!tnx……..

  • BRYAN LAROYA says:

    CAN I CONNECT A TONE CONTROL HERE SIR?….ACTUALLY I AM FROM PHILIPPINES…………

  • BRYAN LAROYA says:

    HELLO!….I WANT TO BUILT THIS CIRCUIT….I JUST WANT TO CLARIFY IF THAT CIRCUIT IS WORKING GREAT!??……TNX….

  • Seetharaman says:

    Hi Pekka Langer you have to use 30-0-30 V RMS AC @ 5 Amps secondary transformer of good quality.

  • Pekka Langer says:

    And i got it wrong again… not 60-0-60vac.

  • Pekka Langer says:

    Sorry. i meant 30-0-30 vac and 60-0-60 vac

  • Pekka Langer says:

    i was thinking about rewiring the secondary on a microwave oven transformer, how many amps would the new cable in the secondary need to be rated for 35+35 vac.
    5A on 35vac or 5amp on 90vac ?
    a fitting transformer around here would cost about 100euros

  • seetharaman says:

    Hi JRY all ceramics as per PCB are required for the stability of the amplifier. The circuit is the basic one for good quality components and layout. since both are not practicable you have to add these components to avoid the shortfalls

  • maroon says:

    tanks!
    it’s good circuit!

  • jclv says:

    it is working as my hope thanks

  • Tomi says:

    Thanks Seetharaman! That did the trick, I love this amp, works perfectly.

  • jry says:

    @ seetharaman base on your schematic dia. you have C1 TO C3 but on your pcb layout you have C1 TO C11,, ceramics is not included on your schematic dia. it is nessesary or not

  • seetharaman says:

    Hi Tomy it looks like crossover distortion. may be at high volues it is sounding clean and at low volumes it is having distortion. If this is your problem, when your out put transistors are highy mismatched this happens, you can reduce this by measuring the output tansistor collector (any one) current and raising it to 50mA, if it is too low by including a 1/2 watt resistace of 10 to 27 ohms between D1 and D2 such that you achieve the results. do not exceed 75mA.

  • Tomi says:

    Hi Seetharaman,

    I really like the simple design of this. My problem is distortion that is coming out if I try to lower the input signal with any resistors. I’m using this amp to power a 4ohm subwoofer. I have the amp connected to a line level low frequence output of my main amp. I put this amp together based on the exact components that you recommend. I connected 0V to the chassis ground (close to the transformer). I have also connected input common to the same ground point. I’m using 16gauge or larger wires and bus perf board. I can not hear distortion if I don’t use any resistance on signal input. If I try to put 3K normal resitor or 50k pot to the input signal, I get distortion. I have also tried to connect 220PF and 1000PF disk capacitor between the input signal and ground, but no effect. I’m doing probably something obvious wrong, but I just can not understand what that is…

    Your help would be highly appreciated.

  • johndar says:

    thanks also to SEETHARAMAN for the ground detail..
    this amplifier is 100%

  • johndar says:

    This design actually work..
    I followed every steps and it worked..
    thanks…
    I have now an amplifier that has a very clear output.
    nyahahahaha

  • joy thomas says:

    Hai sir

    Thanks for your reply

  • seetharaman says:

    Hi Joy AC RMS X sr. root 2 will be the DC output without load (DC output = V RMS X 1.4.14). With load it dpends on the regulation of the transformer. hence with 32-0-32 you will get 45-0-45 volts DC.

  • joy thomas says:

    Hai seetharaman

    I woud like the 100 watt rms Poweramplifier, I can use 32 0 32 ac out put transformer, how much dc volt will come the rectifier out put.

    thanking you

  • seetharaman says:

    Hi Johnda ground should be connected to 0 volt reference supply as there are both negative and positive voltages are used to energise the amp. please refer to amps power supply circuit

  • seetharaman says:

    Hi Navales you have to use only darlington transistors in this circuit. with regular transistors it will work in low voltage as you raise the voltage the no signal current will increase to full rating and beyond and destroy the output transistors. you have to adjust bias etc, which is a the basics. try to use the published circuits as it is for positive results as the published circuits are well tested.

  • navales says:

    I have changed the 2 power transistors to a1904 and 5198, a 500 watts power transistor of KONZERT amplifiers then it works to a supply -12 o +12, but during the time I powered it into a -30 o +30 volts… 5A fuse blows… now my question is… what is the difference of tip darlington pair transistor among other transistors? if there is a replacement for that tip transistor that is cheaper than tip… can you please tell me or send it to my email..navalesaryan@yahoo.com. i need your help… thanksssss… your reply is highly needed and appreciated. good afternoon.

  • johnda says:

    uhhmm…
    im still new in making amplifiers..
    my problem is the power source..
    where would put the ground?
    I think its not in the negative

  • kilipan says:

    in this schamatic 150w ampl. the all capacitor did’t swo how much volt u can put?c1,c2,c3……including the power supply c1,c2,c3,c4…..all this capacitor did’t swo how much can put?pleeeseee…….imfom. me…this ergent!!t.Q…

  • nithin says:

    plese send 2000watts rms amplifier circute diagram
    my mail id

  • seetharaman says:

    Hi Vash you please refer to my sept 17th comment that site gives you the updated modifications and layout, use them for your success.

  • vash says:

    can anyone send me a layout on this circuit because i have still dificulties on it i already troubleshoot it but it’s still not working

  • Zahid says:

    hi

    plz never minde i have not understand in english.
    plz give me a woofer circuit 200w
    easy circuit
    and power full bass controler
    and max speaker 8″ +5″*2
    Thanx all

  • seetharaman says:

    Hi Navales you can use the following site’s data
    http://pcb.jspayne.com/150wattamp.html

  • navales says:

    can you please send me a complete pcb layout of this project tip 147. thank you. ( navalesaryan@yahoo.com

  • seetharaman says:

    Hi NKWENTI there is no protection circuit available for this simple amplifier. you have to take care of speaker impedance(not less than 8 ohms), peak DC supply voltage(+40 and -40 volts should not be exceeded at any time) and loose contacts in speaker connection. you cannot bridge, any mistake will destroy all the transistors may be rectifier and power pack also may blow off.

  • Nkwenti says:

    Hello.
    I found this site interesting about this amplifier. My problems with the schematic is this, After i assembled the power amplifier in stereo mode, only one channel was working, the other channel only humm and only the TIP 147 gets hot, but as for the other channel, it gives me good sound, also why is it that the amplifier gets damaged very fast??

    Then please i am really interested to build this amplifier in bridge mode, can i just build the amplifier and bridge it just like how TDA 7294 is bridged?? can i please have a simple circuit for speaker protection that can be used with this amplifier??
    Any support will be appreciated.
    Thanks all

  • Andy says:

    Hi Admin thanks for response the thing is on the output even if I connect them together the positive and negative polarity no distortion sound comes. It should make a disortion sound if amp is alive I think.

  • Riyazzkhanzz says:

    I like the circuit and i like to build it in stereo.what changes should be done in the power supply(ie;Ampere of the transformer).

  • winston says:

    hi….since i completed my amplifier,every time i connect 2 60watts speakers i always experience a hum sound whenever i turn the pot to the end but when i only connect one 60w speaker,it does not occur.what should be the problem and what should i do because i really need to connect the two speakers???please help…

  • ARTOIS says:

    HI ALL
    IVE CLEARED ALL MY PROBLEMS WITH THIS ONE CANT USE A 10K POT ONLY 1K INLINE TO AMP AND IT WORKS GREAT I DIDNT BELIEVE THE SCHEMATIC AT FIRST THATS Y I DID IT TO CHECK FOR MYSELF IM SURPRIZED ITS ACTUALLY A POWER LITTLE AMP FOR THE MONEY IF SOMEONE WANTS A PCB EMAIL ME(ejhgbb@gmail.com).instead of bc558-bc556 transformer 36v-0-36v regulated 50v,otherwise all the rest by the book.txs for a great sight and txs mr SEETHARAMAN for the power supply circuit u send me.
    cheers john

  • artois says:

    I did this amp but instead of bc558 I used bc556 and I connected a 10k pot but its not working correctly lot of hum I’ve done a few amps with success but this one has me puzzled,are the bc556 the cause used a 36- 0 36 volt trx,iu know its low but even if it pushes out 50w I’m happy.what could the problem be any help pls. When I measure output volt on speaker line I get 42ma but as I turn the pot it goes to 200ma plus then down again.at full volume not bad but down bad. Help pls

  • cooldon says:

    Hi seetharaman
    i just got the Tip 142 and i am don with this circuit.it is working perfect for me,i love it.
    SEETHARAMAN i must say i am greatful for your asistance.
    Pls can i get the circuit diagram for 12volt car amp with a output of 140watt,pls i need this one so bad.
    I will be waiting tanks

  • winston says:

    Its a very simple but effective amplifier,completed mine about a week ago and it works great.But the speakers i have are only 60w so instead of putting 220ohms i put 2k to retard output and improve the stability.

  • cooldon says:

    hi seetharaman.
    Pls want the resistor that can step down 25v,15v and 12v to 3v and 5v pls.
    I will be waiting tanks.

  • admin says:

    Reply to ANDY

    2200 uF/ 16V capacitors are not at all sufficient

    Use the one i shown in the power supply circuit

  • seetharaman says:

    Hi Cooldon kindly list what is available in your market (even it is not Darling-ton transistor) then i can suggest.
    Hi Vysakh is correct use with 50 volt DC rating.

  • vysakh says:

    check your rectifier output. If need please add 4700mfd capacitor for filtering

  • Andy says:

    I am hearing alot distortion. Is this maybe because of the capacitors that I used to the rectifier. The caps are 16v 2200uf.
    Any help please?
    Thanks

  • harry says:

    it’s a simple but huge power amplifier, nice…..

  • cooldon says:

    Hi seetharaman,
    I am jst coming back from the market,i still can get 2SD2390 (2SB1560,Pls help me i need to biuld this circuit.
    I will be waiting,
    tanks.

  • cooldon says:

    seetharaman, i’ saw the reply tanks every much

  • cooldon says:

    WINSTON,i most say tanks man.i am so much greatful

  • cooldon says:

    i most say tanks man.i am so much greatful

  • seetharaman says:

    Hi Winston you can use 0.5 ohms 10watts. Maximum voltage is plus minus 45 volts DC. 32-0-32 volts @3amps maximum for unregulated supply.

  • winston says:

    hi…i was wondering instead of using a pair of 0.33ohms,can i put a pair of 0.5ohms for replacements.And what is the maximum voltage for amplifier?please reply i need to conclude.

  • seetharaman says:

    Hi Cooldon you can use 2SD2390 (2SB1560 is the PNP pair of this) as replacement. in place of 1.5k one 1k and 470 ohms in series or you can use 3.3k in parallel with 2.7K if available.

  • cooldon says:

    pls i will be waiting

  • cooldon says:

    Hi somebody,
    Hi everyone,
    am cris from JOS IN NIGERIA.pls i need somebodys asistants pls.i want biuld this circuit.but when i went to the market to buy the parts they dont have R1 1.5 and Q1 Tip 142 pls i want the replacement for this componet.pls send it to my email,youngcooldon@yahoo.com

  • JAKUV says:

    I WANT DOWNLOAD ALL FILES BUT FAILED..
    CAN YOU HELP ME..
    I WANT A LIST OF COMPONENTS INCLUDING THE TYPES OF WIRES FOR CERTAINTY..

  • seetharaman says:

    Hi Andy measure always at the collector of output transistor, connected to positive rail.
    Hi Jakuv
    use the following site PCB drawing includes rectifier and filter capacitors
    http://www.diyaudiotr.com/islecler/tammetin.php?metinid=6&durum=e#sonyorum

  • JAKUV says:

    HI..
    I WANT A LAYOUT PCB FOR THIS CICRCUIT INCLUDING A POWER SUPPLY..
    EMAIL AT tinytech99@yahoo.com
    PLEASE HELP ME FOR MY FINAL PROJECT..

  • Andy says:

    Seetaraman thanks for explaining technically but I’m not that technical :( What should I do with my MM to test it? Should I put current measuring on Tip142 base to collector?
    Thanks

  • seetharaman says:

    Hi Masood try this circuit a proven one.
    http://sound.westhost.com/project101.htm

  • masood says:

    dear sir,
    this circuit works very well and i salute this circuit .i want a circuit 300w using 2sk1058 and 2sj162.please send me on my facebook alvi.masood251@gmail.com.thanking you.

  • seetharaman says:

    Hi Andy for a class B amplifier with signal only they should conduct otherwise it should not draw any current theoretically. One output transistor will conduct for 180deg of the input signal and the other balance 180deg. But due to mismatch between the transistors it is not practicable. This will give raise the transfer of conduction from one transistor to other one, may for a small angle both may not conduct. This will start giving crossover distortion.(high volume level will sound ok but very low volume signal will be highly distorted. To avoid this a small forward bias is given to the output transistors (without signal say 50 to 100ma, such that they conduct little over 180deg so there is a overlap between their conduction). This current is called standing current. This is normally measured in the collector circuit of the output transistor without any input signal.

  • mustafa says:

    required from any one good amplifier circuit + its PCb

  • Andy says:

    Seetharam what did you mean collector current without any input signal. Can you please clarify?
    I am hearing alot of distortion from my circuit :(

  • varma says:

    Tanx a lot. . .

  • seetharaman says:

    Hi Verma guaranteed RMS output is >100 watts with 8 ohms speaker and >150watts with 4 ohms load. it is recommended to use 8 ohms speaker as there is no protection circuits used, only simple fuse protection against short circuit of the output is provided.

  • varma says:

    Wat must be d impedance . . .8 or 4 in ckt it is givn 8 n in description 4. . . . .

  • varma says:

    Tanx ,n wher can i learn d basics of audio amp

  • seetharaman says:

    Hi Varma 10″ or 12″ with free cone movement, not a rigid one.
    Hi Andy TIP142 collector current without any input signal.

  • varma says:

    N can u plz giv me a link wher i can learn basics abt audio amplifiers . . .

  • varma says:

    Tanx again for ur response ,which kind n size of driver is better for subwoofer using d above 150w ckt. . .

  • Andy says:

    Hi Seetharaman thanks again. Sorry regarding my little tech knowledge but I need spoon feeding :) . When you said check standing current through output transistors, it should be around 50 to 100mA. Which are the output transistors those TIP ones? and I check collector to emitter? Which one you’re refering the output transistor?
    Thanks

  • seetharaman says:

    Hi Varma you can use the following project best one earlier appeared in Circuitstoday, with full cetails.
    http://electroschematics.blogspot.com/2011/04/filter-preamp-subwoofer.html
    for TDA1562Q
    http://amplifiers-wave.blogspot.com/2010/12/50w-tda1562.html

  • varma says:

    And, Can u plz send me a subwoofer ckt using tda1562q . . . .plz do reply

  • varma says:

    Well tanx a lot seetharaman for ur response ,can u plz giv me d links of subwoofer filter appropriate for dis ckt . . .

  • varma says:

    Well tanx a lot for ur response ,can u plz giv me d links of subwoofer filter appropriate for dis ckt . . .

  • seetharaman says:

    Hi Andy you may feed a quality music from your ipod, through a volume control of 22K or 47K to the amplifier and listen. If the quality is good then amp is ok. if not check standing current through output transistors, it should be around 50 to 100mA. if not check the output transistor wiring. check the circuit thoroughly for errors correct them. it is a proven circuit with the transistors recommended.

  • mos says:

    thank u SEETHARAMAN for ur imediate response. it has worked for me. am fine now

  • Andy says:

    Hi Seetharaman thanks for response. Is there a way that I can check it without preamp? cause a hi gain of distortion is coming from the speaker. I tried a one transistor pre amp but still nothing came out with mic maybe need a more powerful pre amp?
    Thanks

  • seetharaman says:

    Hi Mos connect 10 ohms 25 watts as dummy load in place of speaker and check the voltage across this resistance, it should be just a few milli-volt. if it is high check for mistakes in the component / wiring.

    Hi Andy the input requirement for the rated output is 200mV RMS Mic signal will be around 1 to 3 mV. Hence you require a pre-amplifier gain of around 70 to 200.

  • Andy says:

    I read on this forum that one needs a pre-amp to this amplifier for mic maybe this is my problem I will build a small pre amp and see.

  • mos says:

    hi admin.mos from nairobi and am pleased with ur circuit. its awesome, except for one problem i experience at startup of the amplifier where i hear a thud noise from the speaker . what should i do coz the voltage there is 35v dc. plz assist before my speakers blow off. thank u in advance

  • seetharaman says:

    Hi Varma use this amplifier after the sub-woofer filter. From your DVD player feed the sub woofer output directly to this amplifier using a potentiometer to balance the Low Bass level.

  • varma says:

    can anyone plz tell me how 2 use dis ckt for a subwoofer

  • Andy says:

    Today I’ve changed the transistors. Only loud distortion is coming out nothing from mic :(

  • Andy says:

    I think I am using wrong transistors. The guy of the electronic store told me that BD243c;BD241 and BD244c are good instead those Tip transistors but when I saw their datasheet they are not darlington :( . So I have to go and get the right equivalents if I don’t find them.
    Thanks

  • Madhu says:

    I was very enthusiaistic about the amp, after reading comments. i took time and did things diligently, i did everything from scratch including making my own PCB
    getting transformer made from custom shop,I built the amp, but I was totally dissapointed with the experiments result,

    I used 50-0-50v 5amp
    when i measure the voltage was around 58-60v
    Audio input is around 12-20mv
    i used 1.5E 6w instead of .33E 7w which turned to red hot the moment i turned the power on
    later i changed the resistor to .5E 10w same thing it turned red hot with internal wires visible.
    i had to switch it off before it is burnt.

    Can any one help me troubleshoot the amp.

  • Mordis Ellis says:

    Here i have an HWCAT IC CSC2003P,Is there any simple circuit you can suggest for me?

  • Mordis Ellis says:

    Seetheran,i have here an IC2822,Which circuit can i design using it?give full details pliz.again on dealing with a 150w amplifier i can’t find the nf capacitors.and my havit HV-A35 amplifier ic is burnt so i cant find LM4863D IC which one can i replace with?please help.

  • I was actually looking for a 600watts amplifier design from the foundation to the finishing of the project.

  • Andy says:

    Yes for sure I did that but I did this circuit on a bread board to test and I’m thinking that certain components not contacting well.

  • Seetharaman says:

    Hi Andy you require both plus and minus supply. with + & – 12 volt you will get distorted low sound.

  • Andy says:

    Hi Seetharaman thanks for response. I cannot make this circuit work with 12v supply don’t know why :( . I am using 243C 241 and 244c instead of the Tip142/41/147 transistors.
    I connected a mic to try to hear something but nothing till now.
    Still testing.

  • Seetharaman says:

    Hi Hengilbert Thanks for your observations. your ideas are correct but these components need not be mounted on the heat sink, the circuit will get over compensated, hence it can be just nearby. The presets are always a problem for the constructors, with least tools hence it is always preferred to eliminate these complexities to enable them to have successful results without any disappointment, in the first attempt itself.

  • Hengilbert says:

    Hi Seetharaman,

    you can mount the tip41c to the heatsink alongside with tip142 and 147.Adjust it first to minimum and slowly adjust.
    or with the original circuit,you must put the diodes near the heatsink to sense the heat.

  • Mordis Ellis says:

    I have again the two IC’s (CSC2822 and CSC2003P)so i’m wondering which circuit can i construct with those two?

  • Mordis Ellis says:

    Hi!i have a havit HV-A35 Speake with built in amplifire with an ic LM4863D which is damaged and so i can’t find it in stores,which one else can i use to replace the LM4863D?PLEASE GIVE ALL SUITABLE IC’s.

  • Mordis Ellis says:

    Which transistors can i use except the stated ones?i’m in Lesotho.

  • Seetharaman says:

    Hi Hingilbert it is ok but the preset adjustment will be critical and over a period of time they give problem and out put current will raise damaging out put transistors, the modification of the above site also will give thermal compensation as above but for the indicated preset problems.

  • Hengilbert says:

    any modifications on these circuit??
    i have an idea.
    http://imageshack.us/photo/my-images/38/150wattamplifercircuit.png/

  • Seetharaman says:

    Hi Mordis all capacitors are rated for 50volts. if you can give us what is available in your place we can suggest you which one you can use as equivallent

  • Mordis Ellis says:

    Hi! I want to deal with a 150 watt amplifier but the problem is that the voltages of the capacitors are not stated and i cn’t fint some of the transistors in my place,coul anyone please help with the voltages?i’l b more than happy if i can get them.

  • Seetharaman says:

    Hi Andy this amp will give some highly distorted sound. with plus and minus 12 volt from the 12 volt transformer. nothing will blow.

  • Andy says:

    Hi I am trying to work this ciruit with a 12v transformer to a 2w speaker. Do I blow them both?
    Thanks

  • MIKE says:

    ok….thanks for helping…

  • Seetharaman says:

    Hi Mike of course you can substitute a 10+10 stereo amplifier. you can place it in between the pre-amp out and 10 watt stereo amplifier.

  • MIKE says:

    ….so purely op-amp and no other elements needed??

  • MIKE says:

    hi there, is it ok instead of two amplifiers(10w rms) i will substitute a stereo aplifier at the same wattage??

    …and where do i place this circuit?..is it ok to place it after my preamp? (my preamp is also an op-amp)….

  • Seetharaman says:

    Hi Mike you can use two operational amplifiers in one, connect Left channel signal to non inverting input and Right channel signal to inverting input the out signal will be left – right signal feed it to an amplifier of around 10 watt RMS and place speaker at the rear left. Carry out vice-versa you will get R-L signal; feed it to another 10watt amplifier and place the speaker at rear right. with mono signal your sound image will appear at the front center other speakers will be dead. with stereo signal you will get the surround effect.

  • MIKE says:

    Hi there, do you have some additional circuit use to generate multichannel and incorporate it with existing two channel(Right and Left)???

    other suggestions?………

  • Seetharaman says:

    Hi Dieudonne you have to use PNP and NPN power transistors with zener diodes etc please refer to active series pass regulators.

  • Dieudonne says:

    And can i use 2x100ohms 1watt on either power (+/-) as a pass regulator?

  • Dieudonne says:

    which type should i use thanks.

  • Seetharaman says:

    Hi Dieudonne it is not possible in this application as the load current is not constant and varying one as per the volume level kept at the amplifier (power delivered), hence you have to use series pass regulators for both positive and negative supply.

  • Dieudonne says:

    Hi i want to regulate the power of my transformer from 45v to 35v by using a POT. Which resistant should i use.

  • Seetharaman says:

    Hi Mark012 connect a 4.7k in series with the slider of the control to input of the amplifier. add 470 PF in parallel to R7. Now connect 0 volt reference bus to chassis at the input socket. (earthing to chassis from 0 volt bus should be done at one place only multiple grounding will give raise to severe hum).

  • Nesa says:

    Hi, I want to ask the same, about connection PCB ground and chassis earth. Do I have to wire direct link or put some resistor or diode?

  • Marko12 says:

    Hi there. At the end of my preamp there’s a 47k pot. Should I put some component between pot an input of amplifier or not? Does it change input gain of power amp? And what about conection of a PCB ground and chassis?

  • Seetharaman says:

    Hi Mic inter change the speaker terminal and try the feed back phase will change still no effect reduce main amplifier coupling capacitor to lower value may be 2200pf or so. most scientific method will be introduce a graphic equalizer bet ween pre amp and main amp and reduce level of each pot at a time and one pot or two should solve your problem.

  • MIKE says:

    hi there, my next problem is the noise feedback created when i put my microphone near to the loudspeaker….

    do you have some circuit design or suggestions to eliminate this feedback?…

  • MIKE says:

    hi,….ok so no need to replace my output transformer…thanks for helping,,,….

    ok, I will try it…

  • Seetharaman says:

    Hi Mic your filter capacitor should be at-least 10000uF. your amplifier ground and booster amplifier ground should be connected at only one place. ensure no hum is introduced from the main amplifier. you may have to give a overall feed back to first amplifier from booster amplifier out put to linearize the amplifier. with this your amp should work fine.

  • MIKE says:

    Hi there, I’ve change the biasing resistors and have a current of 29mA and the music is good but i am not satisfied because there is a humming noise……is it because of the power supply? or still there is another problem?,…my power supply by the way is not regulated only filters….

    or should i increase the power of my output transformer to greater value because i have only 50watts?….pls…help me…

  • MIKE says:

    hi, can you email it to me your schematic diagram of transformer coupled booster?

    actually I made an experiment, from 470 ohms i reduce it to 300 ohms, and i find out that the music is ok, but i notice when i decrease the volume i heard humming noise…

    i will wait your design, thanks….

  • Seetharaman says:

    Hi Mike without input to your coupling transformer check the current drawn by the out put stage (2 X MJ2955)if it is around 25 to 50mA, it is ok if less increase 12 ohms to 15 etc. If high reduce to 10 etc. Once you are satisfied now feed the input to coupling transformer through a 1K pot. Now check whether the distortion is reducing. now vary the drive to coupling transformer and listen.

  • MIKE says:

    My power supply is 12V,6A. I’m using transistors value of MJ2955…..

    so, what should I do with my coupling transformer?….

  • Seetharaman says:

    Hi Mike Your 25 watt amplifier will saturate the driver transformer cores. this will lead to severe distortion. your bias resistances are OK but you have not mentioned the supply voltage to your push-pull add on circuit and about the PNP transistors whether they are germanium or silicon to give further comments.

  • MIKE says:

    hi there, i build a transformer coupled push-pull amplifier using PNP transistors. My plan is to boost my 25W amplifier. But then, i come up with distortion, both input and output transformer are center tap and biasing resistors R1=12ohm, R2= 470ohm….can you help me solve my problem……

    and pls. email it at micburn18@yahoo.com.. thanks…

  • Seetharaman says:

    Hi Dieudonne you can use up to a maximum of 35-0-35 volts transformer for this circuit.

  • Dieudonne says:

    can i use 45volts transformer

  • Marko12 says:

    Hi Mr.Seetharaman, I have compiled amplifier by all the instructions (change R8 and R9 to 10watt, put a 470p cap on colector-base on both darlingtons, have a zobel network – 0.1uF with 10R 1watt, change C1 to 100uF, crossover distortion diodes are 1x 1N4007 in series with 2x 1N4003 and 12ohm resistor, have a 40-0-40 DC 270mV transformer, use 2x 8 ohm celestions speakers) but when turn ON the amp, there is a huge low noise and sound isn’t clean, there’s a still some distortion. What now? I got a good RMS power but and lot of noise too….??? Do you suggesting to continue with this amp and find a solution or made another for myself??? Im a musician and want something fine “selfmade amp” for myself.

  • Seetharaman says:

    Hi Dieudonne you can use 50K pot.

  • Dieudonne Dorwu says:

    can i use 50k pot/100k pot instead of 10k pot.Because i only got 50k and 100k pots.

  • Adil Shamim says:

    hi i build this circuit when i power on my speaker blow (4 ohms 80 watts) i used 45 0 45 power supply .any one solve this problem

  • Seetharaman says:

    Hi Mark012 it looks like your speaker impedance is low hence with high volumes the peak out put current exceeds the safe limit of out put transistors. You can increase emitter resistance to 0.47 ohms 10 watts. You kindly refer to my motional feed back amplifier the protective diodes in parallel to output transistors and the Zobel network also can be included as additional protection.
    http://www.circuitstoday.com/motional-feed-back-amplifier

  • Marko12 says:

    I need answer! If anyone knows a solution???

  • Marko12 says:

    Mr. Seetharaman, problem solved about output, it was my mistake about R7. But…I have another problem now. Everything works great until push up volume to about 8/10. Darlington transistor blows up at that volume! What now? I have a large heatsink from older amplifier and think that’s not a problem.
    Should I change R8 and R9 to 7-10 watts or what?
    Thanks for responding….

  • Seetharaman says:

    0.33 ohms 10W could be used.

  • iqu says:

    hai

    this circuit is perfect, but if the load is 8ohm 8″speaker with tweeter and use la 3161 head pre + baxandall tone circuit system need for hearing quality

    regarads

    iqu

  • Dieudonne Dorwu says:

    I used 5w0.33 and when i aplified it, the transistors went off. Because i couldn’t the 7watts. And i ask can i use 10watts.

  • Seetharaman says:

    Hi Mark012 these are perfectly OK. Try by i ncreasing C1 from 10uF to 47uF. already the amplifier gain is around 100, hence i feel your input level is insufficient drive the amplifier.

  • marko12 says:

    Hi again Seetharaman, I still have a problem with not enough output power!?! On my PCB I use 2x bc556 instead of bc558/ R8 and R9 are 2x 0.33 5W resistors/ diodes are 1x 1N4007 + 2x 4003 in series with 12ohm resistor. Everything else is like this original circuit.
    Is this componets are problem or something else???
    Thanks for helping and responding…

  • mos says:

    thank you a lot for the circuit. i have finally made it but with omission of R1 and R7. for me its working better than having the two resistors in place. from Nairobi Kenya

  • mos says:

    i tried it but wont work at all. do not know what to do

  • Seetharaman says:

    Hi Mark012 with 42-0-42 DC supply you should get more than 160 watts. May be your input drive is not sufficient. You require 300mV RMS input signal for the rated out put. Just try connecting 100uF 25 volt in parallel with 33 ohms (R10) the sound should become bold. You can try with 45 0 45 volt 6Amps power supply. As with lower impedance speakers you require a higher peak current capability from the power supply.

  • marko12 says:

    Mr.SEETHARAMAN, I try this circuit amp with good hi-gain guitar preamp and I got a about 60-70W RMS at 4ohm (2 speakers parallel at 8 ohm 100W each)!?! I compare my amp with a guitar amp “Marshall AVT 50 (50W power)” at the maximum power and looks like almost the same output power. So what’s a point to get a 100-150W RMS with this amp schematic.
    TIP 142 and 147 works at 100V and can handle 125W maximum. I use 42-0 -42 volts at 4A.
    Sory if I’m boring you but I need at least a 100W RMS power for live gigs playing…
    Is this circuit realy give a 150W RMS power or I did something wrong???
    Thanks for understanding….

  • Seetharaman says:

    Hi Richard Tip142/147 are Darlington pair with a current gain of around 1000 but C5198 is just a transistor with a gain of just around 60,hence cannot be used.

  • richard says:

    can i use c5198/a1941 instead of tip142/147?

  • chris says:

    @kambo
    I’ve used 1/2W resistors. Not much current gets through them so i believe 1/4W could be used too

  • chris says:

    Very good project and extremely efficient for driving subwoofers. Just add a potensiometer between input and source and let there be music!

    Just install efficient heat spreaders on tip/bdw, they get HOT!

    Thanks!

  • kambo says:

    What is power (watts) of the rest of resistors used on this 150w amp.

  • kambo says:

    plz help equivarent of ceramic capacitor 103 and 2k470j how do i convert them to uf.

  • athan says:

    Hi circuitstoday, i would like to ask favor from you can you send me please PCB layout of 100watts subwoofer, 150watts & low pass filter. just send it to my email ad. thank you very much for youre help.

  • chris says:

    Hi, this amplifier looks promising… I want to use it on a 4Ohm subwoofer, a 25-0-25 ac transformer 6Amp should be appropriate, right?

    Seetharaman could i have a project description sent in my email? Thanks in advance xhorium@hotmail.com

  • I have a new PCB layout done and circuit boards are available. The new layout includes provisions for bypass capacitors that add stability. Also, the layout accommodates both the low and high wattage TIP transistors packages (TO-220, TO-218/247).

    http://pcb.jspayne.com/150wattamp.html

  • wine lay says:

    hey……
    i’m myanmar.
    220volt amplifier circuit diargram see.

  • Seetharaman says:

    Hi Marko12 you can use this amp with suitable guitar preamp. you can fix this also in side a good solid speaker enclosure

  • marko12 says:

    I want to try to build this amp but can I use it as a guitar amp? How good is this amp for a guitar and a guitar cabinets

  • rogelio says:

    great circuit,.. it works very fine,..

  • Kambo says:

    24-0-24v, 5A. Power supply for 150w amp will it be okey?

  • Seetharaman says:

    Hi Sebin you can do that. it will be a nice sub woofer amplifier. Kindly add a 330PF ceramic disc capacitor between Q3 collector and base.

  • sebin says:

    is it possible o connect a bass filter before the input and use it as a sub woofer amplifier

  • no comments it work fine….i built this one,very good circute

  • rogelio says:

    gud day, seetharaman,. nice IC. can i use 12 amperes as a power supply to tda2030? LM4702 is not available here in our place..

  • Seetharaman says:

    Hi Rogelio LM4702 (a power amplifier driver IC)will give an output of more than 60volt drive for the output transistors which as per their application data 300 watts RMS power with least distortion. you can use +100 & -100 volt supply to get 7 volt RMS with quite low distortion of less than 0.001% . Anice IC to try if available freely i the market.
    you may go through national datasheet

    http://www.national.com/ds/LM/LM4702.pdf

  • rogelio says:

    hi, seetharaman. tnx 4 the reply last feb 23,. uh, can i ask u what is the output power of LM4702b?

  • TEL says:

    ,seetharaman..tnx 4 d rply.. I thought u will send me the project capability and limitati0ns to my email..? U said dat in ur c0mment ryt? C0z u said, the space here is n0t sufficient.. I didn’t receive an email fr0m u..

  • Seetharaman says:

    Hi Tel refer my earlier comment
    Hi Laeka to enjoy high fidelity music you require a good soft thumping low frequency reproduction. this can be achieved through a good quality medium to high power amplifier. it is not that you will be blasting always at 150watts but with modern digital equipments capable of producing 90dB dynamic range you can enjoy the music without any distortion creeping in. This circuit is a simple straight forward good design, that is an added advantage.

  • TEL says:

    ,ok. I will f0llow you.. Can u give me the significance of this project? teljarabe@yahoo.com this is my email..

  • Seetharaman says:

    Hi Tel the project limitation is 150 watts into 8 ohms speaker. this limitation is due to the thermal resistance of the output Darlington pair transistors. send me your email id i will give you full description. here the space may not be sufficient.

  • TEL says:

    ,and also can u give me the project description of this circuit? Tenk u..

  • TEL says:

    ,seetharaman..tnx 4 d rply, i hav an0der questi0n. What is the pr0ject capability of this circuit and its limitati0ns? Pls rply..tenk u s0 much.

  • Seetharaman says:

    Hi Tel +44 – 0 -44 volt 2Amp supply will be just right. If you are assembling stereo amp with this use RCA-Phono sockets for the input. (most rugged and fail safe)
    Hi Laeka to enjoy high fidelity music you require a good soft thumping low frequency reproduction. this can be achieved through a good quality medium to high power amplifier. it is not that you will be blasting always at 150watts but with modern digital equipments capable of producing 90dB dynamic range you can enjoy the music without any distortion creeping in.

  • laeka says:

    what is the general objective of this project pls reply thanks

  • tel says:

    seetharaman can you please give me the complete computation of this circuit? i need it so badly, our submission of this project is fast approaching…plssss.. and what kind of babay jack am i going to use? mono or stereo?

  • tel says:

    seetharaman i need ur reply,, is my power supply right? it has 44 for positive and 44 for negative?

  • Seetharaman says:

    Hi Rogelio wattage is V (AC voltage available across speaker terminals with load)square divided by impedance of the speaker. hence you will get half the out put for 8 ohms instead of 4 ohms. that is 50watts.

  • rogelio says:

    gud day,! thanks a lot seetharaman,. uh, wat will be the power output on 8 ohms?

  • Seetharaman says:

    Hi Rogelio +/- 30 volt can be used. the power output to 4 ohms speaker will be around 100Watts. you require only a 2amp supply for stereo 4amps that is all the requiremen, which TIP142/147 pair can handle.

  • rogelio says:

    hi seetharaman, can i use a +/-30 15amp to the tip147 & tip142.?

  • Nkwenti says:

    This amplifier is amazing, i have build the amplifier several times, but the Amplifier is too complicated, at times when i assemble it in Mono, it works well, but when i do it in Stereo, i have problems, then the transistors are very sensitive and quick to be blown, that is my problems, but i usually run the amplifier with a +/- 35v instead of +/-45, why do i keep having this problems?? please any help forwarded to me at dnkwenti@gmail.com will be appreciated, my greetings to you all.
    ……………….PEACE AND GOOD LUCK………………..

  • Seetharaman says:

    Hi Crystel you can use 2nos capacitors in series with parallel distributing resistances, can be 2.2K 0.5watts.

  • Crystel says:

    ,can someone tell me wat capacitor can i replace in the p0wer supply of this amplifier. The 63v is n0t available here in manila.. Only 50v I need a reply.. Plss…

  • itsme_chad says:

    does know the alternate transistor for bd708

  • richard says:

    hi sir seetharaman im done with the circuit tnx…
    i have a question i have amplifier konzert av 301 with
    22 0 22 volts and A1941/C5198 transistor.. if i make the transformer 35 0 35 does make the amplifier add its watts? this will not damage the amplifier? tnx

  • richard says:

    tnx seetharaman.. am drilling the pcb.. i hope it works… tnx

  • Seetharaman says:

    Hi Richard you can use TIP41C in the place of TIP41.
    TIP41 Vceo 40 Volt
    TIP41A 60 Volt
    TIP41B 80 Volt
    TIP41C 100 Volt
    But for the above parameter there is no other difference between them.

  • richard says:

    sorry its not bc558 its tip41c.. can i use that? tnx

  • richard says:

    Hi admin there is no bc558 available.. bc558c is only available here can i use that transistor? tnx

  • shreya says:

    HI seetharaman

    i am very happy to meet you in this site after long time

    what about 500w pa amp still construction is going on?

    i am very eager to do that amp

    thank you

  • victor says:

    please give a practical transistor combination for the npn and pnp darlington transistors.eg,tip147 is (tip41+d718+in4007).

  • Seetharaman says:

    Hi Fozu R3 and R5 should be 3.3k.ohms(3k3 / 1 watt). for mic you have to have an additional amplification of 50 to 100 before feeding to the amplifier.
    you can use the circuit appeared earlier in circuits today
    http://www.circuitstoday.com/3-input-microphone-preamplifier

  • As for a mic input, you would need a pre-amp to get enough gain.

  • As stated in this article, you need a good quality power supply. In my experience you need power supply decoupling caps very close to the amp circuit. In addition a cap(10-100pf) from C to B on the TIP41 helps a lot. Also, you can add a 100pf(approx) from input to common. It is fairly easy to scab in these caps on the bottom of your board.

    As posted earlier in this thread, addition of an RC network on the output adds stability.

    I am working on a layout that incorporates these suggestions. I will post when it is ready.

  • fozu says:

    hi all i hv tyied above circuit with 1)R8 & R9=10watt.33ohm 2)R3 &R5=33k(33000ohm) 3) power supply =35-0-35 4)audio in =mic 5) pcb lay out stephen’s
    my prob is when i give it voltage input tip142 & 147 get warmer plzzzzz anybody who has tried it tel me what is the basic or main problem in it
    response me soon plzzzzzzzz

  • fozu says:

    using mic this circuit is not working:( pcb lay out used is Stephen’s design…..

  • fozu says:

    plzzzzzz teme about audio i/p?

  • fozu says:

    hi Seetharaman i have try this circuit as my project with 35-0-35 i/p supply, 8ohm 100watt, but i need to knw about i/p if i use a mic will it work? or what can i do to input audio?

  • oneil says:

    i need some specs for the 150 watt.

  • alphavic says:

    hello, for those people making this amp there first project make sure not to use imitation output transistors, especially residing in Philippines!marami kasing fake!

  • CALOY says:

    wat will happen if the output terminal and the input terminal for power supply is near from each other???
    hum noise???

  • shreya says:

    Hi seetharaman did you remember me what about 500w pa amp

  • CALOY says:

    @ shailendra007

    check your pcb design.

  • babila says:

    i am happy to know that this circuit is funtioning well. but i want to ask if we can use a supply of 30 0 -30v. i also wish to request for the 1500w inverter circuit. i am waiting pleaseeeeeeeeeeeeeeeeeee.

  • hi, i was made this project on general p.c.b but it was not working , what was reason i dont know ,please help me

  • Seetharaman says:

    Hi Caloy 3 diodes are just sufficient to operate on Class B mode.
    Hi Basha you can turn a thyristor on with the positive gate pulse but cannot control with gate pulse there after. You have to reduce the current flow through thyrister below its holding current to switch off.

  • Basha says:

    Is there any thyristor which turns on negative gate voltage and turns off on positive gate voltage.

  • I got good results with 3.3K resistors in place of the 33K resistors.

  • CALOY says:

    how many bias diodes do you require which will work the best???

  • Seetharaman says:

    Hi Edcube the quality can be improved by adding one more diode and a 10 to 22ohms resistance in series with the existing 2 bias diodes D1 and D2. Ensure the no signal currnet through the output transistors are within 50mA.

  • CALOY says:

    HAPPY NEW YEAR TO ALL…!!!!

  • edcube says:

    I built this amp. It works but the crossover distortion is quite bad especially at low power levels. It can be seen very clearly on an oscilloscope. It seems the comment previously posted by somebody is true. (That comment is gone though – removed?.) This amp is OK as long as you are not looking for high quality sound.

  • CALOY says:

    thanks for that info mr.seetharaman…32-0-32 is not available here…

  • seetharaman says:

    Hi Caloy you can use 24-0-24 which will produce dc 34-0-34. with 3amps current capability will ensure 125watts into 4 ohms speaker. with 8 ohms speaker 62watts will be delivered.

  • CALOY says:

    is it ok if i use 24-0-24 transformer for this project????

  • Seetharaman says:

    Hi DAN46 TIP147 is a PNP Darlington pair. you can try using BD140 with TIP2955 in Darlington with 1N5404 / BA148 diode as indicated in the above pin out details.

  • Segzy says:

    Plsssss!!! I ned d cal for dis amp.as much i can get.i ned it 4my writup.cal 4rm d power suply,stages cal and power consmp&los.u can email me.thaankss in advanc
    my email is boyolu4real@yahoo.com.i’m watin badly

  • dan46 says:

    HI pls how can i get the tip147 transistor?? or can i use tip3055 for tip147?

  • Seetharaman says:

    Hi Caloy 0.47 ohms 10watts will do.

  • CALOY says:

    is it ok if i use .47 ohm 15watt resistors for R8 & R9???

  • Segzy says:

    D circuit’s wokin gud .gud job

  • Seetharaman says:

    Thanks Stephen

  • For all who want, I have created a PCB layout of this 150 watt amplifier. There is a correct size PDF of the PCB layout. Goto http://pcb.jspayne.com/150wattamp.html for more info.

  • Seetharaman says:

    The one off test model is under rigorous tests.

  • shreya says:

    Hi seetharaman what about 500watt amplifier

  • Seetharaman says:

    Hi Segzy kindly use the following circuit which appeared earlier in Circuits today.
    http://www.circuitstoday.com/40v-dual-power-supply
    use 32 – 0 – 32 transformer in place of 30-0-30

  • Segzy says:

    Pls i ned diag4 d +/-45v dualpower suply witout IC

  • Segzy says:

    Pls can i build +/-45vdual power suply witout using IC?i ned hlp on d circt diag

  • Seetharaman says:

    Hi Sabri use the 100 watts inverter appeared earlier in circuits today with 555 as per diagram shown below
    http://skema-elektronik.blogspot.com/2008/12/inverter-12v-dc-to-120-230v-dc-with-ic.html

  • SABRI says:

    mr.seetharaman
    I NEED CIRCUIT CAN BE CONVERT 12V DC TO 220V AC @60HZ ??
    CAN BE USED 555 IN THIS CIRCUIT?????
    THANKS

  • saju says:

    I HAVE REPLACED BOTH 142&147 AND ASLO ADDED A GOOG HEAT SINK ALONG WITH HF STABILITY COMPONENTS. THANKS AGAIN FOR YOUR VALUABLE ADVICE.MY AMP IS FUNCTIONAL NOW. CAN YOU SEND ME THE 5.1 SYSTEM DIAGRAM. i HAVE 4 AMPS WITH 01 SUB OF 100W.

  • Seetharaman says:

    Hi Segzy you have to use both positive and negative supply. with one supply only it will not work.

  • Segzy says:

    Is it comp 2use dual pwer suply 4d amp?can i use+45v btwn d +ve tminal&GND 4d amp?can i also 12-0-12 voltage doubler 2obtain 48v 4d amp

  • saju says:

    thank you very much. I found the collector emitter short and hope it was due to the heat sink (as I forgot to fix them on first power on). I will do the rest of the modification and let u know the results.

  • Seetharaman says:

    Hi Saju checkup for transistor collector emitter short (though base emitter and base collector is ok). check the polarity of bias diodes. R5 = R3 = 3.3K (3K3). have you fixed HF stability components. 1k with 470PF at the input. 100PF between collector and base of Q3. fix 0.1 uF ceramic disc in positive and negative power supply rails. with this it should work. all the best

  • saju says:

    hi caloy
    The PCB been adopted from the diagram on the web.

  • saju says:

    I am using +/- 35V with 5Amp fuse. And also have the PCB which is available on net. I have gone through your earlier comments and doubts whether the fuse is blowing because of the HF instability?. The very first time when I swiched the Amp on it amplified the signal. There after no respose to the input also!!!!!!?
    All the componets are in good condition
    kindly advice me what to do.

  • CALOY says:

    how about 3amps on 300mA device??

  • saju says:

    hi, Seetharaman
    I have tried the circuit but the fuses on both + and – power supply keeps blowing. I have done the visual inspection could not find any wrong connection. please advice me

  • Seetharaman says:

    Hi Adnan you can use 0.47ohms 5watts resistance for each transistor, so that each transistor is taken care from over current(equal distribution of current will take place) all will share the current equally.
    Hi Saju a simple fast acting fuse can protect the speaker from burnout.
    Hi Caloy only 900mA will be consumed the balance is the additonal capability of the power supply, that will be in reserve. nothing will happen to the components. if you have a 40 watt bulb connect to your domestic mains which is capable of 5KW before blowing the fuse, the 40 watt bulb will consum only 40 watts not more than that.

  • CALOY says:

    is there a possibility that the device will be destroyed???

  • CALOY says:

    what will happen if i use a 2 amp power supply on a device that requires only a 900mA of current???

  • saju says:

    can you provide speaker protection circuits for the amp

  • Adnan says:

    HOW CAN I CALCULATE THE EMITTER RESISTANCE FOR PROPER PARALLELING?

  • Seetharaman says:

    Hi Adnan proper way of paralleling with emitter split resistance it can double the power with lower impedance speaker. with 45-0-45 and 4 ohms speaker you can achieve 300 watts,

  • Adnan says:

    if we use 2xTIP147,2xTIP142,TIP41 in parallel @ 45-0-45v 4A
    will the output of amplifier increase from 150watts?

  • Seetharaman says:

    Hi Saju you can use down to + – 25 volts. Note the resistances R3 and R5 are 3.3K ohms.
    Hi Jack The amplifier gain is set at 100. (R4 / R2)
    With 45 volt supply and with 8 ohms speaker to achieve 42 volt pk to pk ( 42 / rt2 = 30 volt RMS i.e 30 X 30 / 8 = 112.5 watts RMS) you require 42V pk pk / 100 = 0.42V pk to pk.
    For clues in construction please go through my comments from the beginning.

  • saju says:

    hi, Seetharaman
    Can we use +/- 35V supply for this circuit.

  • Jack Daniel says:

    Hi, Seetharaman, I’m Jack Daniel
    this amp is look simple to build, can you please explain what is the full specification such as
    min & max of DC Voltage for this circuit.
    Secondly what is the input signal voltage peak to peak, so we don’t overload the poweramp circuit which can create unwanted distorted sound.

  • Seetharaman says:

    Hi Adnan it should be 10-0-10 volt 25 Amp capacity (6-0-6 shown is incorrect) transformer will be best suited as you have to take care of saturation voltage of transistors. collector to collector shorted indicates that they are all on the same heat sink without insulation. otherwise the circuit is in order

  • Adnan says:

    http://www.eleccircuit.com/500w-inverter-12v-to-220v-by-40472n3055/

    plz visit this site and suggest the transformer i cant understand plz help me?

  • Seetharaman says:

    please refer to my earlier comment:
    seetharaman says: June 25, 2010 at 9:18 am Hi Bryce You can connect the volume contron in the input terminals of the amplifier. cold end to common, pot variable point to input coupling capacitor and signal between the earthy end and the other end of the potentiometer.
    you can use 50 K for 47K. ( JIS is 25K 50K 100K but western preferred value std is 22, 47, 100)

  • Kudster says:

    What about a volume control?

  • Seetharaman says:

    Hi Caloy you can use 0.47 ohms. it will affect the performance of very low impedance speaker as the peak current through the output transistor will get limitted. with speakers of 4 ohms and above it will not matter.

  • CALOY says:

    is it ok if i use .47ohm 10 watt resistor for R8 & R9 ???

  • Seetharaman says:

    Hi Caloy no possibility at all. The amp will draw the required current only though the power supply is capable of 6amps. Here it is designed for 5mA only, so nothing should happen

  • CALOY says:

    is there a possibility that the bc558 transistors will explode if i use 6 amps of current ????

  • jerry says:

    do you have PCB pattern of this amplifier?

  • Seetharaman says:

    Hi Adnan yes you are correct as per calculation. the circuit to which you are going to feed should be capable of handling the voltage, current and power.

  • Adnan says:

    if we give 50-0-50v 4 ampere means 400watts of power and suppose our amplifier is of 75% efficient then AC output is 300 watts?is this true or not

  • Seetharaman says:

    Hi Adnan the power supply gives the power to amplifier after consuming some it delivers the balance as power output to speaker(efficiency). amplifier power output cannot be greater than power supply capability.
    Hi Mounica in the spec there is a small mistake it should be 4 ohms system 300 watts 8 ohms system 150 watts. if your woofer is 4 ohms, use 4 ohms tweeter in parallel (in phase) with woofer through a non polar capacitor of 5uF if system is 8 ohms use 2.5uF(you can even use ceiling fan capacitor, if non polar is not available). if you feel the volume of tweeter is quite high then add a 22 ohms wirw wound 10 watt pot in series with tweeter and adjust for just matching volume level with woofer, while playing good music.

  • mounica says:

    Hello seetharaman

    I want to use the tweeter along with the speaker for specifications see the link http://www.ahujaradios.com/ProductSpecification.asp?prd_id=204&id=7&sc_id=49

    how i have to use it. something like resistor ,capacitor

  • Adnan says:

    is there any relation between DC supply power in watts and amplified power in watts?

  • Seetharaman says:

    No these analog amplifier’s efficiency cannot be increased. To acheive higher efficiency you should go for class d amplifiers.

  • Adnan says:

    can we increase the efficiency of this amplifier?

  • Seetharaman says:

    Hi Caloy 0.4 is not a standard value you can get 0.47uF (470n). 39PF is just 39PF only.
    This amplifier though it can be called as class B. it is just class AB push pull amplifier.

  • CALOY says:

    what class of amplifier is this???

  • CALOY says:

    what is the capacitance code of 0.4uF & 39pf capacitor???

  • Seetharaman says:

    Hi Sagar leave the center tap use the full winding it will be 24volt. use a bridge rectifier and filter capacitot to get 24 volt dc output.
    Hi Adnan yes you can give both the channel inputs at a time.

  • Adnan says:

    can i give two inputs (both right and left) at a time???

  • Adnan says:

    can i give two inputs(both right and left) at a time?

  • sagar says:

    if i have 12v center tap transformer how can i get 24v from it

  • Seetharaman says:

    Hi Caloy with 5 watts the output current can be 4amps continuous with 7 watts it will be 4.6 amps. in fact with audio in it will be only varrying current hence 5 watts is more than sufficient. if you want to drive with sine wave at full power continuous then use 7 or 10 watts. you can use freely available diodes 6A1 four numbers.
    Hi Adnan yes you are correct you can use 2nos 10uF in series to achieve 5uF. (resistance in parllel formula will hold good for capacitors in series).

  • Adnan says:

    can i use 10uf in series to get 5uf?

  • CALOY says:

    if 6 amp bridge rectifier is not available…what model of diode should i use???

  • CALOY says:

    mr.seetharaman

    http://www.diyaudiotr.com/islecler/tammetin.php?metinid=6&durum=e#sonyorum

    R8 & R9 is 0.47 ohm @ 5 watt…what will be the effect???

  • Seetharaman says:

    Hi Nightingale first you can start with a variable power supply using LM317 which will be useful for all your projects. then you can proceed with projects using around 20 components and useful for domestic requirements.

  • Seetharaman says:

    Hi Adnan it will be limitted to your power supply capability. That is 64 X 4 = 256watts of energy is available. say if the amplifier efficiency is 80% then you can get around 200watts. againg this is dendant on the output transistor capability its thermal conductivity etc.

  • Adnan says:

    you tell me last time that if i bridge this amplifier it will give me 900w @ 4ohms but it will require 4 times current and you suggested me 32-0-32v @12amp transformer right but if i use 32-0-34 transformer @4A how much output will decrease in bridged mode?

  • nightingale says:

    hey m a first year engineering student,i want to know some initial and interesting projects as i havent studied alot yet..reply soon

  • Seetharaman says:

    Hi Caloy you can use 6amps transformer as the requirement is just 5 amps it will be better to use slightly a higher rated transformer.

  • CALOY says:

    is it ok if i use 6 amp transformer for the amplifier???

  • Seetharaman says:

    Hi Caloy the circuit diagram is correct. component list shows IC as TL084 it should be TL082. C5 is not shown but 220 ohms is shown in the pcb layout, change it to 0.4uF and out put resistance R10 is shown as 100 ohms, it should be 220 ohms. the first photo of the assembled module is correct. the circuit is working ok.

  • Adnan says:

    if i make this amplifier two times and bridge them then what will be the calculated output if using 35-0-35v @4A transformer? plz calculate it and tell me and show the calculation that will be helpful to me??

  • patrick vaz says:

    Hi Seetharaman,
    Thanks a heap, spot on, except for 2 nos internal resistors of 10K, which can be managed,
    regards & Cheers!!!

  • Seetharaman says:

    Hi Patrick BC107 transistor is the equivallent you can refer the following site
    http://engisys.info/transistor.php?transistor=48078

  • CALOY says:

    mr.seetharaman,kindly look at this low pass filter….

    http://english.cxem.net/amplifier/amplifier21.php

    some parts of the pcb layout is different from the schematic diagram….

    what should i follow???the schematic diagram or the pcb layout…???

  • CALOY says:

    thanks mr. seetharaman…

    more power….

  • patrick vaz says:

    Hi Admin,
    Pls can u let me know what is the equivalent Transistor for UN4211, Iam new in bangalore (india) and iam unable to find the transistor nor any help from the shop vendors regarding equivalents
    regards

  • Seetharaman says:

    Hi Caloy you can visit the following site which gives you all details for the above amplifier including pcb layout etc
    http://www.diyaudiotr.com/islecler/tammetin.php?metinid=6&durum=e#sonyorum

  • CALOY says:

    MR.seetharaman,,,when will you send the pcb layout…i’ve already bought the components…

    i made a pcb layout using double layer pcb…

    will you pls check it….

    will you pls give me your e-mail account and i will send you my pcb layout & check if there are errors……..

  • CALOY says:

    MR.seetharaman,,,when will you send the pcb layout…i’ve already bought the components…

    i made a pcb layout using double layer pcb…

    will you pls check it….

    will you pls give me your e-mail account and i will send you my pcb layout & check if there are errors…

  • Seetharaman says:

    Hi Adnan for a cross over frequency of approx 3KHz you require 3.3uF for 8 ohms load and for 6ohms it will be around 5uF. 100 volt is chosen to take care of the output voltage swing of the amplifier. capacitor should be in series with the tweeter. the whole thing should be in parallel with the woofer.
    yes i will send

  • Adnan says:

    will you plz mail me the circuit of 500watts amplifier with shreya????

  • Adnan says:

    you tell me in 2nd last comment to use 5uf 100v capacitor for 50watts tweeter tell me how will i decide the value of capacitor according to input of amplifier and speakers for connecting in parallel same as u tell me?
    is the capacitor connect in series or in parallel?

  • Seetharaman says:

    Hi Adnan feed connect the meter in AC voltage range across speaker, feed some loud music to the amplifier. read the maximum AC voltage reached by the meter. this voltage square devided by 6 will give you the power outpur. For getting RMS power you have to feed 1KHz sine wave input and go on increasing it till the sound is clear without any distortion. measure the AC voltage and calculate as above.

  • Adnan says:

    Ive made this amplifier using 35-0-35 transformer 2x3300uf 71v capacitors with 2 0.1uf ceramic with 6ohms 150watts woofer
    how can i calculate the output power using multimeter tell me the method plz?

  • Adnan says:

    plz send me the pcb diagram of above amplifier and also the power supply circuit?

  • Seetharaman says:

    Hi Adnan you can connect you tweeter in parallel with the woofer through a 5 uF 100 volt non polar capacitor.
    Hi Emmi I have replied to your email

  • Adnan says:

    i have connected a 150watts woofer for base and i want to connect a tweeter of 50w 4ohms in parallel tell me how can i connect tweeter?

  • emmi says:

    hi seetharaman your given circuit is producing more distortion there is no clarity

    i gave 12v to it

  • Adnan says:

    ive made this apmlifier using 35-0-35 transformer 2x3300uf 71v capacitors with 2 0.1uf ceramic with 6ohms 150watts woofer
    how can i calculate the output power using multimeter tell me the method plz?

  • Jack Daniel says:

    Hi, Seetharaman, if you don’t mind, can you please provide some details about the power supply which will robust enough for stereo channel?
    Do we have the full specifications for this circuit.
    I am interested to build one for my self.

  • Ryan says:

    HI can send me the PCV plan thank you

  • Seetharaman says:

    Hi Emmi you can use this circuit befor your tone control circuit. if no tone control circuit use with your sub woofer or 150 watts amplifier.

  • emmi says:

    Thank you for your quick reply

    i have to use your circuit after my Aux circuit or use instead of it

  • emmi says:

    hello today i have sent a mail to you (seethasub at hotmail)

    please check it and kindly send me reply please its very urgent

  • Seetharaman says:

    Hi Nidesh it can be TIP41 A or B or C. TIP141 is an NPN darlington not our requirement
    Hi Caloy i will mail you soon
    Hi Shreya the design is getting frozen still some reliability test have to be completed. pl wait.
    Hi Emmi the PCB layout and copper track will be send to you soon

  • nidesh says:

    transister Q3 ,IS IT TIP141 OR TIP 41 ,GIVE ME ANSWER IMMEDIATELY,THANKYOU.

  • CALOY says:

    hi mr.seetharaman
    here is my e-mail add

    pjc_valerio@yahoo.com

    thanks a lot…more power…

  • shreya says:

    Hi seetharaman

    what about my amplifier?

  • emmi says:

    plz send me the pcb diagram of both 100watt and 150watt amps

    emmizeb@gmail.com

    and i have send you a mail to seethasub@hotmail.com but you didn’t give any reply why?

  • emmi says:

    plz send me the pcb diagram of both 100watt and 150watt amps along with them

    emmizeb@gmail.com

    and i have send you a mail to seethasub@hotmail.com but you didn’t give any reply why?

  • Adnan says:

    plz send me the pcb diagram with caloy
    adnan_khan_yzai@hotmail.com

  • Seetharaman says:

    Hi Caloy i will send you the PCB drawing soon
    Hi Adnan with respect to chassis or common the voltage is 50 hence should not be a problem.

  • CALOY says:

    can you give me some tips for designing the pcb of this amp..

    thanks….

  • CALOY says:

    can u give me some tips for designing the pcb of this amp…

    thanks…

  • CALOY says:

    Thanks Seetharaman….

  • Adnan says:

    its mean 50-0-50 dc volts @ 4amp are not dangerous?
    but if accidentally touch the wire will it leave the human or not?

  • Seetharaman says:

    Hi Caloy you can use this amp as sub woofer amp use external sub woofer filter.
    Hi Adnan it depends on the resistivity of the body(wetness etc) even 100 volt DC can kill a human under certain conditions

  • Adnan says:

    what is the dangerous range of dc voltages which can kill a human?

  • Seetharaman says:

    Hi Adnan you can use two 8 ohms 150 watts speakers in parallel, which become 4 ohms and with 300watts power handling capacity.

  • CALOY says:

    HELLO…CAN I USE THIS AMP AS A SUBWOOFER PWER AMP…???

  • Adnan says:

    if a amplifier gives 300 watts at 4 ohm
    can we connect two 150 watts speakers in parallel?

  • seetharaman says:

    Hi Hengilbert This amplifier requires +30 – 0 – -30 Volt hence the total requirement is 60volts. hence you may not be in a position to use 30volt only.

  • Hengilbert says:

    Hi Seetharaman,

    Can i have a supply of 0-30v only?And what will be the new diagram?

  • shreya says:

    Thank you seetharaman my mail id is mounicashreya@ymail.com please send me soon

  • seetharaman says:

    Hi Shreya you require around 500watts RMS Power please wait for some time I will forward a nice high power protected amplifier.

  • shreya says:

    Hi seetharaman

    i want hybrid variety

    my purpose is to use in open area meetings for a crowd of 500 people (for music and speech)

  • seetharaman says:

    Hi Shreya what is your requirement a nice suitable reliable design can be published. you want discreate or IC based or hybrid variety. purpose.

  • shreya says:

    Hi seetharaman

    why this site has only two high power amps?
    i want more high power amps like 250watt 500watt….

  • seetharaman says:

    Hi Adnan This will be the best power supply suited for this IC. for filter you can add 0.1uF ceramic in parellel with the 15000uF to take care of HF instability.

  • adnan says:

    power supply for Tda7295 ic transformer 24-0-24v @4amp with 6amp bridge with 2x15000uf capacitor is OK or any addition in capacitors are needed?

  • jagadish says:

    hai seetharaman but tip 147 and 142 can hadle 100 volt right ,other wise can we change any resistor value to reduce volt

    and also please tell me how to reduce 55 volt to 30 volt using resistor value

    regrads
    jagadish

  • jagadish says:

    hai Onkelf i used processor heatsink with fan

    cheer jagadish

  • jagadish says:

    this is jagadish thank you seetharaman can you please tell me any ic handle 75 0 75 volt and 7 amp

    other wise stk 4050 v where i can find

  • seetharaman says:

    Hi Adnan why not please go ahead use a good heat sink for output trasistors. use 2amps fast acting fuse for + & – power supply line to protect output transistors during an inadvertant shorting of speaker wires.

  • adnan says:

    can i use 2x8ohm speakers in series at 35-0-35v @ 4 amp

  • seetharaman says:

    Hi Adnan 35 0 35 will give a DC of 50volts which will lead beyond the maximum dissipation of the transistors may damage the output transistors with transients. 30 0 30 will be ideal for 8 ohms speaker. with 35 0 35 use 15 ohms or higher impedance speakers.

  • shreya says:

    Hi seetharaman
    subject: 100watt sub-woofer
    i shorted R9 & R10 the temperature of transistors decreased but Q7 is getting hotter than Q5 why ?

  • adnan says:

    can i use 35-0-35v @4amp with 6amp bridge with 2x4700uf capacitors for this amplifier?

  • Anthony Deane says:

    Hello seetharaman,this circuir required a dual volt supply,but i don’t have a 30v-0-30v transformer,however if i used a 12v-0-12v transformer will this work.You can e-mail me at ajdeane03@yahoo.com.

  • adnan says:

    hi admin wheres the seetha raman

  • adnan says:

    hi if i use 35-0-35v @4A will the amplifier works or not?

  • Onkelf says:

    And what would the °C/W be per amplifier if the transistors shared heatsink? the best i can get around here is 1,1°C/W
    or could i use a intel p4 heatsink with fan ?

  • Onkelf says:

    hello. sorry o bother you with another transformer related question but i need a powersupply 2 of these amps i have recently built. i can get a 35vac 600va transformer for a resonable price, do you think the amps can take it or is +49,5 0 -49,5 volts to much ?

  • shreya says:

    can i use 2n3773 instead of 2n3055?

  • seetharaman says:

    Hi Shreya the resistances are shown above use 8.2K and 39 ohms you can use BY127 or 1N5404 for the protective diodes.
    Hi Jagadish the maximum voltage for transformer is 32-0-32 @ 4amps or higher.
    Hi Emmi noise reduction (DNL) at the input of the amplifier.

  • emmi says:

    Hello seetharaman
    can you give me noise reduction circuit for this amplifier

  • JAGADISH PRABU says:

    any one please help me can i use 75 0 75 7 amps in rail for this circuit i am having 55 0 55 transformer this okey

  • JAGADISH PRABU says:

    HAI GUYS STILL I AM USING THIS CIRCUIT ITS WORKING FINE AND GREAT CAN I USE 75 0 75 IN RAIL VOLT IT HANDLE

  • shreya says:

    can you give me the resistance values,diodes and how to connect if you have circuit diagram you can send to mounicashreya@ymail.com

    can i use 2n3773 instead of 2n3055?

  • seetharaman says:

    Hi Shreya sorry i got confused bet 100watt sub woofer and 150 watts. TO3 equivallent with higher power is MJ3001 / MJ2501. if you cannot find them use BD139-2N3055 with BD140-2N2955 as compementry pair for the out put stage with external resistances and diodes to achieve protection.

  • shreya says:

    Hi seetharaman

    in the given diagram Q1 and Q2 are not input stage they are in output stage

    now tell me the TO3 model instead of TIP142 and TIP147

    if we use TO3 type what changes have to do in the circuit

  • seetharaman says:

    You cannot use in the input stage, TO3 transistors which will generate lots of noise and input impedance will be very low. you have to use low noise small signal high voltage transistors in the input stages.

  • shreya says:

    Hi! seetharaman

    i want q1 and q2 to be TO3 type can you tell me the model of TO3 casing transistor
    also tell other corrections to the circuit if i use TO3 type

  • seetharaman says:

    Hi Scot
    try the following link. it gives full details including the PCB
    http://www.diyaudiotr.com/islecler/tammetin.php?metinid=6&durum=e#sonyorum

  • Scot says:

    I searched the thread, and didn’t see this question. Does anybody have a jpg of the PCB? I would like to make a PCB using laser-printer method, but need a pic. If anyone has done a layout with a PCB creator, please post a link.

    Thanks,
    Scot

  • seetharaman says:

    Hi Adnan you will be feeding constant voltage to amplifier but its out put voltage to speaker will vary as per the loudness you want. since speaker is of constant resistance the varing voltage to speaker will produce varying current through the speaker hence the wattage.

  • adnan says:

    plz send me any example or any circuit on my email or here with variable voltage n current power supply??

  • adnan says:

    its mean i will vary both of voltage and current as my load requirement????

  • seetharaman says:

    Hi Adnan yes you can use for any current from 0 to 12 amps at 30volt. Voltage will be constant as per load requirement the current flow varies. the current consumed depends on the load resistance.

  • adnan says:

    if i have a power supply of 30 volts 12 amp.Is this is possible to get 30 volts 6amperes from the 30volts 12amps power supply?

  • adnan says:

    if i have a power supply of 30 volts 12 amp.Is this is possible to get 30 volts 6amperes from the 30volts 12amps power supply????

  • adnan says:

    no meex its for a 500watts amplifiers

  • meex says:

    500V/A…? are you sure..? thats alot… thats 500W meaning max 10A on 50VAC ..is that a microwave transformer..? :p

  • adnan says:

    a transformer have rating 50-0-50 500va than how much ampere of transformer is this?

  • meex says:

    @ADNAN – if u have speakers that need 150W of power and 24V, that means you need: (150W / 24V) = 6.25A for speakers to work at full strnght but its recommended that you use 7A

  • meex says:

    @ADNAN – nothing will happen, just the transformator (that is supplying your device) will not get hot when working. if you give your device a transformator with 12V and, for examle, 750 mA, it could work but probably not too long. ampers define strenght of transformator, so its like if u need $1.000 every mont but u get $4.000 it will be easy for you to survive but if you need $1000 and you get only $750 you will die :p …hehe….

  • adnan says:

    if a device need 12volts 1 ampere but we give 12volts 4 amperes?what will happen?will the device works or get burn??

  • seetharaman says:

    In series with the supply positive and negative lead. one at a time if you have one meter only.

  • joel says:

    Hi sitharaman

    Thank you for your reply

    The polarity of the diodes is correct

    Where i have to check the standard current please tell me

  • seetharaman says:

    Hi Adnan if you are making a stereo amplifier (two identical amplifiers of above)
    Hi Joel check the polarity of bias diodes. short R9 & R10 and check the standind current may come down to just few mA, without any signal input to amplifier. at low volumes it may sound highly distorted. you can adjust these values to increase the standing current to 50mA or so. By shorting R9 & R10 is not reducing the current then there is some wiring mistake kindly check up thoroughly.
    Hi Amol I am not in orkut.

  • Amol says:

    Hi seetharaman, are you in orkut???

  • joel says:

    Hi seetharaman

    I have built the 100-watt-sub-woofer-amplifier

    The problem is when i connect 8ohms 100watt woofer at minimum sound Q5&Q7 are getting very hot and smoke is coming out from R16 & R14 even though i have used a good and big heat sink

    i have changed only R16 & R14 i.e 0.33 to 0.50ohms
    i have used 32-0-32 transformer and changed Q1&Q2 as you told me

    could you please give your valuable solution to decrease hotness

    I am waiting for your reply

  • adnan says:

    what do you mean by 2 channel i cant understand??

  • seetharaman says:

    Hi AK you can use 50 volt supply provided it is +25 -0- -25 volts. The power will get reduced to around 75watts with 8 ohms speaker and 150watts into 4 ohms speaker.

  • seetharaman says:

    Hi Adnan you can use for 2 channels and ensure that you use 8 ohms or higher impedance speaker and the output transistors on a very good heat sink.
    Hi Amol the bass distortion is due to long DC supply leads to the out put stages. ensure that you use a minimum 16 gauge copper wire and ensure the zero voltage is connected to the metal chassis at the input point only. similarly the speaker common lead should not be connected to chassis it should get connected to filter capacitors common. this should iron out all your low frequecy distortion.

  • adnan says:

    can i use 35-0-35 4 amperes for the above 150w amplifier????

  • Amol says:

    Hi seetharaman, thank you brother i will do it.my another problem is how can i reduce bass distortion without compromising volume range of my amplifire

  • adnan says:

    you suggest me the 32-0-32 4 amperes transformer for this amplifier but this is not available in my market i get the 35-0-35 4 amperes transformer
    can i use 35-0-35 4 amperes for the above 150w amplifier????

  • ak says:

    can i use 50V power supply to this amplifier?

  • seetharaman says:

    Hi Amol this problem is due to high frequecy also getting amplified along with 20 to 20KHz audio. hence you have to provide a low pass filter in the power amplifier input a 1k in series with the input and fit a bypass ceramic capacitor 470PF to ground. add 4700PF 100 volt ceramic disc capacitor in parallel with each rectifier in the power supply

  • Amol says:

    Hi seetharaman, i have made 8 channel (stk 4141II x 5) for my pc, its working great, but it creates loud noise like firecracker when somebody turns of tube light,fan etc in my house. will u help me to filter such noise??

  • seetharaman says:

    Hi Adnan incresing current rating of the transformer will not improve anything. It will draw only the required current of around 4 amps.

  • adnan says:

    if i kept the voltage same and increase the current rating to 5A or 6A what will be the output??

  • seetharaman says:

    Hi Adnan it will work. With 8 ohms speaker you will get around 70watts and with 4 ohms load you will get around 140 watts, with this transformer. (one channel only)

  • adnan says:

    if i use 24-0-24 volts 4 ampere transformer will the circuit works or not?
    and what will be the output??

  • seetharaman says:

    Hi Adnan the ceramic is the dielectric between the plates in this capacitor. Normally their value will be between 2.2PF to 1uF with the voltage rating from 16 volt ot few kilo volts. They are well suited for high frequency application.

  • adnan says:

    whats the working of ceramic capacitors

  • seetharaman says:

    Hi Adnan by using higher value capacitors in the power supply the transient response will be very clean, in other words the peak power will sustain so you get a very clean bass response.(for amplifying low frequecies you require lots of power)
    As the electrolytic capacitors are wound they have an inductive element also in it. Hence at higher frequencies the reactance tend to increase like an inductor due to which the power supply impedance will start increasing with respect to frquency, due to common power supply impedance going higher the circuit will become unstable due to complex feed back due to power supply. Hence to avoid this a disc capacitor which is purely capacitive is used in parallel with the electrolytic capacitors. This is very important esp. in digital circuits.

  • adnan says:

    if i change the capacitor to 12000uf then what will be change in the output?

    n why we use the ceramic disc capacitor in supplies??

  • seetharaman says:

    Hi Adnan that will be fine. you wll get a clean power of 120watt RMS into 8 ohms load. and a peak power of around 225 watts into 8 ohms load.

  • adnan says:

    i have the power supply of 30-0-30 4 ampere with 2x4700uf 50v capacitor with 0.1uf capacitor
    is the power supply i s ok for above 150watt amplifier???????

  • adnan says:

    will you publish my circuit of 300×2 watts amplifier???

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