Low Cost 150 Watt Amplifier Circuit

In this project, we’re building a simple 150 watt amplifier circuit.


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

PCB’s for this project can be ordered through PCBWay. We shall upload a sample PCB file (for download) shortly.


  • 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.



  1. Seetharaman

    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.

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


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


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

  5. Seetharaman

    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

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

  7. Seetharaman

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


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



  10. seetharaman

    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.

  11. Hengilbert

    Hi Seetharaman,

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

  12. seetharaman

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

  13. 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)

  14. seetharaman

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

  15. Hi seetharaman

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

  16. seetharaman

    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.

  17. 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?

  18. 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


  19. hai Onkelf i used processor heatsink with fan

    cheer jagadish

  20. 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

  21. seetharaman

    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.

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

  23. seetharaman

    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.

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

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

  26. Anthony Deane

    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.

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

  28. 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 ?

  29. 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 ?

  30. seetharaman

    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.

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


    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



  34. 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?

  35. seetharaman

    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.

  36. 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

  37. seetharaman

    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.

  38. 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

  39. 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.


  40. seetharaman

    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.

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

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

  43. seetharaman

    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.

  44. 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?

  45. 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????

  46. 500V/A…? are you sure..? thats alot… thats 500W meaning max 10A on 50VAC ..is that a microwave transformer..? :p

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

  48. @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

  49. @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….

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

  51. seetharaman

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

  52. 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

  53. seetharaman

    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.

  54. 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

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

  56. seetharaman

    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.

  57. seetharaman

    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.

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

  59. 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

  60. 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????

  61. seetharaman

    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

  62. 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??

  63. seetharaman

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

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

  65. seetharaman

    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)

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

  67. seetharaman

    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.

  68. seetharaman

    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.

  69. 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??

  70. seetharaman

    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.

  71. 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???????

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

  73. seetharaman

    Hi Adnan
    Go through the specification of the transistor TIP122 and 127 (they are in plastic casing) hence maximum possible power dissipation is is only 150 watts even with an infinite heat sink, so you have to limit the voltage to 32 volts and speaker impedance to 8 ohms if not you will loose output transistors instantaniouly. If the output transistors are of T03 casing then it is different. http://www.st.com/stonline/books/pdf/docs/4132.pdf

  74. then tell me the maximum voltage rating of transformer for the above 150 watts amplifier?????

  75. seetharaman

    Hi Adnan to get 300 watts into 8 ohms speaker. Vsg / Z = wattage. Hence you require around 38 – 0 – 38 volt transformer by taking a drop of 4 to 5 volts on out put transistors 40 – 0 – 40 @ 3amps will be the best choice.

  76. the circuit 600watts amplifier Ive mail you
    you tell me that amplifier gives 200watts on 8ohm load at 40v-40v
    now tell me how i get 300watt instead of 200watts????

  77. then tell me the maximum voltage rating of transformer for 150 watts amplifier?????

  78. seetharaman

    No Adnan it will be too high it will produce around + – 61volts it will kill the transistors immedeatey. it can be used for the circuit which you have sent to me through email.

  79. you suggest me 32-0-32 4ampere transformer but this one i snot available in my market
    can i use 45-0-45 4amp transformer?

  80. seetharaman

    Hi Roger The filter capacitors are used to convert pulslating AC (after rectifier circuit, you will get one portion of the sine waveform only, say positive going only in a half wave rectifier and both half wave will be positive going in case of full wave rectifier) into pure DC.

  81. hi seetharaman ….can I ask you something…? ..what is the use of filtered capacitor ….that putted in the power supply….?

  82. can i use 80+0 voltage transformer for 150watt amplifier????

  83. seetharaman

    Hi Adnan you have to use positive and negative voltage for LM4702. You have to use 40 – 0 -40 volt transformer.
    with 30 – 0 – 30 as indicated in the diagram can give only 100 watts RMS into 8 ohms load. with 40 – 0 – 40 transformer you can get around 200 watts RMS into 8 ohms load.

  84. can i use 80+0 voltage transformer for this amplifier????

  85. can i use 80+0 voltage transformer for this amplifier?

  86. seetharaman

    Hi Adnan I have got it i will send you a detailed reply on it.

  87. i have an amplifier circuit of 600watts and i want to send u the circuit i want that u suggest the power supply for the amplifier can i send u?if i can then send me Ur email?thank you

  88. i have an amplifier circuit of 600watts and i want to send u the circuit i want tha u suggest the power supply for the amplifier can i send u?if i an then send me ur email?thankyou

  89. seetharaman

    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)
    For baxandal tone contrl any small signal NPN transistor will be OK.

  90. hi seetharaman can i ask about the baxendall tone control that you given, what is the replacement of bc109c? transistor coz its available in our market,,and about this amplifier where can i connect the volume control..?


  91. hi seetharaman im new here can i ask about the baxendall tone control that you have given, what is the replacement of BC109C? because its not available in our market and can i use 50k potentiometer to replace 47k potentiometer?,,

    where can i put the volume control in the amplifier?,

    pls reply,,, thanks

  92. seetharaman

    Hi Sanjay Use a 32-0-32 volt transformer with 200VA rating. Use a bridge rectifier of 5 amps rating from bridge rectifier + output and transformer center zero connect a 4700uf 63 volt this will be +45volt. Connect -ve end of the bridge rectifier and center zero transformer a 4700uF 63volt this will be your -45volts. refer to power supply circuits appeared in circuits today.

  93. sanjayhapaliya

    How to use power supply transformer and capacitor in 150 Watt amplifier circuit give me Ideas Plz?
    who transformer to out dc vlots +/- 45v?

  94. Ive build that amplifier its so good, thanks for your article…

  95. seetharaman

    Hi Adnan Torroidal transformers are small for the rating. since the magnetic field is fully closed no loss highly efficient no leakage to produce hum and buzz and no heating up. Good transient current response hence nice peak output without distortion. but quite expensive. worth the extra money.

  96. what is the performance difference of normal transformer and toroidal transformer?
    why toroidal transformer is prefer for amplifiers

  97. Hi. I want to bridge this amplifier, how i do?. I have 2 aplifiers… Tanks

  98. Hi, I assembled this circuit and it works great. I tried MOSFET IRFP150N power amplifier but it need’s some more pre amplification.

  99. seetharaman

    Hi Adnan please send any tried circuit, i will make a prototype and send it to ADMN to publish the same in Circuitstoday. Thanks.

  100. seetharaman

    Yes Adnan you can use. But you have to ensure whether your amplifier can feed to higher impedance load. If amplifier is rated for 200 watts into 4 ohms load. you can use two 100watts 8 ohms speakers in parallel. or say 200watts into 8 ohms load, then you can use two 100watts 4 ohms speaker in series

  101. can i use two 100watts speakers connected in series as a 200watts speaker?

  102. can i send u a 500 watts inverter circuit on your email?or can i upload my circuits on your website for the guidance like other circuits?

  103. hi seetharaman ….. i just want to ask you ..if you have a face book account . because i want to send you a bass and treble circuits. i just want to ask you about the some parts of the circuit…..like the capacitors voltages…. thanks.

  104. seetharaman

    Hi Adnan
    12 volt 200AH say 10 hour rating 12 X 200AH 2400VAH that is if you draw 240 watts of power it can supply for 10 hours. if you draw 500 watts it may give for little more than 4 hours only. refer to manufacturers catalog for derating.

  105. seetharaman

    Hi Adnan what is the terminal voltage of the battery.

  106. OK let suppose i connect the 5oowatts load power and i connected the 200AH battery plz tell me the output timing of battery and tell me how to calculate the timing of the battery?thanks

  107. seetharaman

    Hi Adnan it depends on the load power requirement and rated AH capacity of the battery.

  108. if i have a ups of 1kw and i use a 200amperes battery how can i calculate the output timing of my ups when battery is fully charged

  109. seetharaman

    Hi Roger The bridge should be rated for 5amps,
    Minimum 4700uF 50volt, one for positive and one for negative. infact i would prefer a pi filter. 4700uF a 0,47 ohms 2 watt ww resistance and again a 4700uF capacitor and a 0.1uF 100volt ceraminc disc capacitor in parallel with it.
    All capacitors should be rated for a minimum of 50 volts.

  110. please tell me the value of bridge diode and the 2 capacitors in the supply sides……….. and also the voltages of all capacitors in the amplifier side…….please ….thanks

  111. and also the voltages of all the capacitors in the circuits ….thanks…..

  112. hi guys ,,,,,, can i ask the value of bridge diode and capacitor to use in the power supply of this 150W amplifier….pls,. i need your reply…

  113. will you plz upload a circuit of a digital clock with am and pm indicators,date and alarms

  114. seetharaman

    Hi friends you can use 32-0-32 with 4 ohms speaker you will get around 110watt RMS power. with 8 ohms load you will get around 55watts RMS.
    Hi Adnan total power supply in the above case is + and -34volt. Hence the max pk to pk voltage across load is 68 volt minus drop across out put transistors say approx 6 volt. Then the pk to pk voltage available across the load is 62 volts. converting it into RMS = (pk to pk / 2 ) / sqrt2. That is 22volt RMS. Hence power = V sq / Z. That is 444 / 4 around 111 wats RMS into 4 ohms.

  115. hi guys. i have a problem, i followed PAPACHIK PCB lay-out and it already finish. my problem is the transformer its required 32-0-32 and we have no available in the market. we have only 24-0-24 6 amps transformer.can i use transformer 24-0-24 6 amp? need your reply guys…. thank you

  116. hi guys. i have a problem, i followed PAPACHIK PCB lay-out and it already finish. my problem is the transformer its required 32-0-32 and we have available in the market. we have only 24-0-24 6 amps transformer.can i use transformer 24-0-24 6 amp? need your reply guys…. thank you

  117. seetharaman

    Hi Adnan 30 – 0 – 30 volt 2 amp will give you plus minus 42 volt DC @ 2 amps. 164 watts of energy for the output circuit with an efficiency of 80% you will get around 132 watts power output into 8 ohms load.

  118. if i use 2Ampere transformer how much the output will be affected?

  119. seetharaman

    Hi Adnan Use 30 – 0 – 30 120Va transformers 2nos with two bridge rectifiers and parellel them on the DC side

  120. excuse me 32-0-32 4A transformer is not available in my market?
    30-0-30 2Amp is available tell me what i do?

  121. yes you are right ive succesfully made regulated power supply,22watt amplifier and led emergency light and all the items are in use in my homes but this is not end ill proceed till im alive in making circuits thankyou i learned many thing and i want more

  122. seetharaman

    Hi Adnan With 8 ohms load you require a transformer of 32 – 0 – 32volt @ 12Amps.
    With 12 Volt AC you will get 220V AC. But if you want to use as an inverter transformer with transistors and 12 volt DC, you will get less voltage, you have to take into account the saturation voltage of the transistor. Preferably 10 to 220 volt transformer you have to use.
    Thank you Adnan I prefer to clear the technical doubts of the constructors so that they will have confidence in building a project, once they are happy with the successful completion of their first attempt it will make them involve more in the subject and learn more.

  123. thankyou for all replies you are a very good learner and helper thankyou Seethaaraman god bless you

  124. ca i use 220 primary and 12 volts secondary transformer in reverse to get 220 volts if input is 12 volts?

    and transformer can operate just in ac volts or also operate in dc volts?

  125. its mean a bridge amplifier requires 16amperes so i have to use a 16 amp transformer am i right?

  126. seetharaman

    Hi Dedi Being an electronic hobbiest must have tried lots of circuits. kindly share your ideas, circuits and experience with our readers.

  127. thanks for your good articles. i’m a electronic hobbiest

  128. seetharaman

    Hi Adnan for bridging no increase in voltage is required in the supply but the current capability should be 4 times, if the speaker impedance remains the same. It is always preferable to use a speaker with little lesser power handling capacity than the amplifier. Say around 80 to 90% of the amplifier rated capacity. 800 watts speaker will be ideal. The reason you can discuss with any loud speaker repair expert, he will explain you in depth.

  129. last time you suggest me the 32-0-32 toroidal transformer for the power supply of this amplifier but when i bridge this amplifier it requires high voltage and current so suggest me the new transformer according to the bridge configuration?

    and 1200watts max input speaker is fit for the 900w output or not?suggest me the diffrent speakers for 900w output

  130. seetharaman

    Hi Adnan This amplifier as such will give you (30 sq / Z)with 8 ohms around 110 watts RMS. into 4 ohms will give you 225watts RMS. In the bridged mode 900Watt RMS into 4 ohms. OK this is theory. The actual out put power depends on the output darlington transistor and the power supply capability. With 8 ohms with the present darlinton pair you can get maximum 200 watts into 8 ohms that too with a good heat sink and cooling. 4 ohms not recommended.

  131. tell me that if i made this amplifier 2 times and then i will bridge them then approximately how much output in watts i’ll get in 4ohms?

  132. can i replace any other darlington transistor for more high out for example i want to increase the output at 600watts can i change the darlingtons?

  133. tell me that if i made this amplifier 2 times and then i will bridge them then approximately how much output in watts i’ll get in 8ohms?

  134. seetharaman

    Hi Adnan if you use an infinite heat sink with forced cooling you can achieve 62.5 watts dissipation maximum from these transistor. with a small head room you can achieve 50 watts dissipation. hence you can achieve only 200watts maximum with an 8 ohms speaker. if you want more power you may have to parallel more number of transistors so that the current can be shared between them. the design will become complicated with protection circuit current limitting etc etc. this is a simple design for a clean 100 watts RMS into 8ohms speaker.

  135. seetharaman

    Hi Adnan any good quality transformer can be used. secondary should be 32 – 0 – 32 volt (64 volt with center tapped) with a VA rating of 400 minimum.
    After bridging with the power transformer as above you will get a guaranteed minimum of 200watt RMS power into 8 ohms load.
    Go in for a good standard make loud speaker with a power rating of minimum 150 watt RMS.

  136. after bridging this amplifier it will give 600watts in 8ohms speakers but if connect the 4ohms speaker thern waht will be the output?
    and if i use 2ohms speakers then what will be the output?

  137. after bridging this amplifier it will gives 600watts in 8ohm speakers but if i use 4ohms speakers then what will be the output?n if i use 2ohm speakers then what will be the output?

  138. how much current a bridge amplifier will required?
    and what is the suitable speaker for the amplifier after bridging i mean to say how much watts speaker will i connect?
    n if toroidal transformer is not available then waht i sthe replacment of the toroidal transformer?

  139. thanks for last reply

    and which typt of transformer configuration i use 32-0 or 32-32?

  140. seetharaman

    Hi Adnan you can use standard 32-0-32 @ 4Amps torroidal transformer with 6amps bridge rectifier and 10,000 uf 63 volts X 2 in parallel with 0.1uf 63 volt is the best power supply with 2 fast acting fuse of 2Amps rating for each channel in both +ve & -ve power supply.

  141. for input voltage which transformer is the best and how much current limit of transformer

  142. seetharaman

    Hi Sowmya you might have gone through my approach in checking the design of automatic LED emergency light. we can analyse in depth each design. if you have any doubt in any part of the circuit that alone can be assembled and the performance can be checked.

  143. ya,,,this is a hot & active topic,i also suggest my friends for apply this.one things,each & every circuit application is not possible for me but i want to verify this so if u send me any procedure to check the circuit that will be better & i also be satisfied most.if possible make me member of this.i want to do something on circuit.

  144. seetharaman

    Hi Sheryll With MP3 player you may not face pboblem, if you use a low pass filter as i have idicated, 1K in series with the input and a 470PF from it to ground. (please refer motional feedback amplifier circuit)
    with cell phone you may get interference heavily if the amplifier is not screened properly and grounded, if you use the cell phone at a distance with long connecting cable you can avoid the interference to a great extent. it is only atrial and error method.

  145. hi seetharaman my input signal is mp3 player/cellphone

  146. plz upload a circuit diagram of bridged amplifier configuration of 150w amplifier i have a woofer which required 600w input so help me how can i bridge this amplifier for 4 times output thankyou

  147. seetharaman

    Hi Adnan you assemble 2 amplifiers and bridge them you will achieve 4 times the power. But power supply should be capable of providing the additional current. 4 times the requirement. the heat sink for output transistors should be very large.

    Hi Sheryll slider I mean the varable portion of the pot (the center tag). 50K rotary pot is fine. may be your input signal is very high what is the source you are using. use a 2.2k to 4.7k in series with the variable tag of the pot and the input capacitor C2.

  148. Dear Seetharaman,

    I don’t have 47K slide potentiometer.. I used 50K knob potentiometer but when i turn the knob to max resistance there’s a noise. The volume did not change..

  149. excuse if i build this amplifier 2 times and can i connect this amplifier in series to get 300watts output if i can then tel me how

  150. Hi All,
    have you a schematic diagram with power amplifier using the vacum tube like EL34 or 807,push pull ballance and complete the impendance with output transformer and input transformer?if you have pleas send to me via email..

    from Jakarta,Indonesia

  151. seetharaman

    Hi Sheryll You can use a 47K potentiometer slider to C2 (10uF) negative and one end of the pot to common. Now connect audio input from any source between both the end of the pots ensuring that the signal of the input source is connected to free end of the pot and the screen (common)to earthy end of the pot.

  152. Thanks Seetharaman.. My problem is in the heatsink.. There’s no heat transfer that’s why the transistors keeps blowing up… thanks again…

    Another thing, can i add a volume control in this circuit? How?

  153. seetharaman

    HI Deedat do you want the complete design calculation.

  154. can you give me the computations of this design?i need it badly…thanks

  155. Seetharaman,

    Thanks for the tips. I will try them out and get back to you.

  156. seetharaman

    Hi James a 200watt rms into 8 ohms, rugged mosfet mono amplifier module will cost you around US$200 plus power supply (Plus, minus 50Volt minimum) pre amp etc. assembled ones will be quite expensive. you may visit the following site.

  157. Hi anyone everyone

    I need to boost my passive woofer which reads as 6ohms
    200w max, what could be the cost, to drive it as good
    as the powered woofers in the 5.1 sets.


  158. seetharaman

    hi prem 32-0-32 is the right transformer to get + and -45volt dc.
    hi sheryll try by reducing HF boost at high volume, if output transistors are not getting heated up after this (with HF cut) it looks like HF instability due to layout problem, High frequency instability are not audible but the current drawn will shoot up indicating instability. Try a 100PF disc capacitor between collector and base of Q3. A HF filter of 1Kohm resistance series connected with 470PF ceramic disc capacitor to ground at the input of the amplifier before C2 should help.

  159. I just tried the circuit but the TIP142 and TIP147 keeps blowing up. The first time it blew up in a few seconds. After working on the heat sink I got it to work for a few minutes with my mp3 player’s volume set to 5/10. But when I turned up the volume to 6/10, the transistors blew up immediately. I am using 8 ohm speakers. my power supply measures 47 volts on the + and the – side. What am I doing wrong?

  160. this an use transformer 32-0-32 5amp pls reply me..

  161. circuit is ok. If i want to apply bass & treable with this circuit,how can i connect?

  162. seetharaman

    Hi Ptero the site given by Papachik gives full details. The PCB (PWB- Printed Wiring Board)) layout is good (only with 2 links). You may try it. I am planning to get the PCB done.

  163. any one will share the pcb layout.pls give us the link or post it here

  164. I have three questions.
    1) Can you run this with just a TIP142 and bypass the TIP147 for lower output or do they absolutely have to compliment each other?

    2)Is there a way to power this off of a single voltage rail (I.E car audio, DC adapter, etc)

    3)If yes to question 2, what needs to be changed to bring current requirement from 45volts to approx 10,12 or 14?

    Thanks in advance,

  165. Hi

    Any one have FN1016 based subwoofer amp circuits

  166. Jon Gregorio

    simplest amp assembled. few components but high power = JG

  167. Hengilbert

    This is the cheapest circuit i have discovered and try it it’s pretty amazing it only costs PHP 300.00

  168. Anthony Deane

    Dear Sir,
    I have change the 2N3903 transistors to BC557 and is still having problem to get the output signal to the speaker.
    Are these the correct transistors TIP 142, 147 and 41 and is this the correct voltage to feed the circuit 45v 5A.
    All the other components used are rated according to the diagram posted on this site. I don’t want to give up at this time please help me.
    I am looking forward for you urgent respond and any members who have completed this project and got through please assist me.You can contact me on my email at ajdeane03@yahoo.com
    Best Wishes

    • admin

      Reply to Anthony Deane
      All transistors are correct. I think there is no problem with the circuit. Pls check your circuit and components.

      Many guys have successfully assembled this circuit .

  169. Anthony Deane

    Dear Sir,
    I have reciently build this 150w amp, all the components used on the circuit are of the correct values, except for the Bc558 transistor. I was given the replacement value which is 2N3903 transistors.I connect them according to the diagram you post but when I powered this amp I am not getting an output signal to the speaker. When I test the circuit the power is going to the 1st transistor. What diganosis can you give me to solve this problem, please email me at ajdeane03@yahoo.com thanks.

    • admin

      Reply to Anthony

      2N3903 is NPN and it is not a replacement for BC558 which is a PNP transistor.That’s the problem.

      2N2907, BC158, BC557, BC177 etc are the suggested replacements for BC558

  170. Seetharaman

    Dear Manoj you can built any preamplifier using both positive and negative power supply if it is to be built in as the output amplier is with dual supply. For externally powered pre amplifier I have tried with Two transistor tone controller circuit appeared in these column and found to be sounding perfectly alright. Kindly inform what are the inputs you wand to handle. happy listening.

  171. Seetharaman

    Hi Nr Gregtherider Yes with one end of the transformer connected to center of two filter capacitors connected in series. other end of the transformer to anode of the first rectifier and also to cathode of second rectifier. cathode of first rectifier to positive end of serially connected filter capacitor and anode of the second rectifier to negative of serially connected filter capacitor. serially connected Capacitors center is taken as zero volt. Only problem is i have to use double the value for the filter capacitor to reduce the ripple and hum. I have used 2 X 4700MFD 63Volt each for both positive and negative supply.
    kindly send your email id to seethasub@hotmail.com for detailed circuits

  172. gregtherider

    @ SEETHARAMAN: Can you please tell me how did you make +-30V from 30V transformer? Voltage doubler? Some schematics would be very helpful!

  173. Hey
    I really liked the circuit seems pretty good. I wanted to build this aong with an uA741 preamp circuit i was wonderin if tht is good or do u have better pre amp circuits in mind?

  174. hello; my problem is the transistor you giving is tip142=tip147 i go to the shop and they ask me tip142=147 is [b or c} can you tell me b or c reply me soon as possible than you.

  175. cled..from philippines

    regards 2 Ryan….gudluck 2 your circuit project!!!!

  176. cled..from philippines

    no comments it work fine….i built dis one

  177. Eng/Ramzi


  178. Hi,
    All of the comment are mostly technical but I would like to know with the suggested diagram and parts is the sound good?
    If I connect this to the output of my PC sound card will it be OK?

  179. Hi, my name is emmanuel from malawi. i tried the circuit and it worked just fine but not for me. so i tried these 200watts 16Amps BDV66D and BDV67D as output transistors but “Hey people” you cant imagin the power that a simple amplifier like this can output. plz change the 33k resistors to 3.3k and increase the wattage of 0.33 resistors to 10 watts. i also have designed a simple hyper bass circuit that works fine with any type of amplifier | it produces exactly hi-fi sound with only ten components|and i would like to share it with you friends. use this email address and the next moment, it will be in your inbox (emmanuel@windowshoppingmalawi.com)Thanks to admin

  180. Hengilbert

    hi…i have decided to use 2N3055 TO-3 type transistor instead of TIP142 and MJ2955 for TIP147..Is it OK???

  181. Hi

    I am making my sub woofer , i am going to try with TIP 142/147 transister only, suggest me on the same, which will be good amp for building sub woofer

  182. Seetharaman

    Hi Cedric
    if 4 diodes are used it will become a class A amplifier, you require a large heat sink to take care of the out put transistor heat dissipation. to operate as class B push pull out put, the out put transistors to be biased just short of conduction hence a maximum of 3 diodes can be used to avoid cross over distortion in these circuits. Happy listening

  183. Seetharaman

    The boostrap capacitor C1 should be 100 MFD not 10MFD as shown (volume and bass response improved dramatically). I have used a 15-0-15 5amp (150VA) car battery charger transformer using as 30 volt transformer and a voltage doubler. to remove the instability and output transistor getting warmed up due to spurious oscillation I have added 100MFD with 0.1mfd in parallel in both positive and negative power supply in the board and also 100PF capacitor between col and base of TIP41. a simple HF filter 1Kohm with 470PF also added to the input circuit. the performance was amazing for such a simple low component count circuit. wishing you all the best for your nice contribution. pl keep it up.

  184. is this circuit still operational at +-33V?? please reply

    • admin

      This circuit will work on +/- 33V, but the output power and performance will be reduced.

  185. Hi

    I wonder if this amplifier can work as bass guitar amplifier?


  186. hii have made this circuit and it is working good i just need to know that it is 33k or 3.3k and i it is tip41 or tip42 can u pls sugest me

  187. G. S. Anand

    PLS clarify that
    a) 33K should be read as 3K3 for R5 & R3
    b) The TIP147 gets warm in the absence of an input,about 25mv appears at the output.what must be done to achieve 0 output in the absence of an input? please help
    c) All transistor amps should have zobel rc networks to keep the amp stable. (10 ohm and a 100n cap will be fine.
    d) I saw an another circuit like yours but there has TIP41 and not TIP42
    e) can 0.33E be replaced by 0.3E 10 W

    PLS modify the Circuit accordingly on the WEB site

  188. In the diagram the transistor Q3 is described as TIP42 (PNP). It must be a TIP41 (NPN)

    • admin

      Yes, you are correct. Q3 is TIP41. Typing mistake from my part. I have corrected the circuit diagram now.

  189. Hello, I simulated this circuit on LiveWire and found that it performed the same with or without C1 (1kHz – 15kHz). Any reason why it is there?

  190. im using +/-18v and instead of the 27k resistor in using a 22k+4.7k in series to get 26.7k and im getting distortion. Are one of these the cause?

  191. Pieter Schmahl

    Hi there,I’m from South Africa..I was suprised how cheap this project costed me compared to quality and power (except for the 300VA transformer I bought..Costed me a fortune!! But nothing to worry about if you can find a suitable one in your scrapbox or garage or wherever)..I just wanted to know,if I want to increase the amount of output power (about 400W or so),should I only repeat the two output transistors and resistors R8 & R9 and put it in parallel?? Thank you

  192. subodh ambale

    this is gr8 ckt . but how can i add bass treble ckt to this ckt . pls ans by circuit diagram

  193. this circuit works amasingly,but how can i add bass treble circuit to this amplifier?

  194. Hi. I am writing from East Africa, Nairobi City. I assembled the 150W circuit using a 50V-0-50V, 3Amp dual power supply. It works great with my 4 ohms, 300 watts speaker!! Its the cheapes amp I ever built! Thank You Admin.

  195. I want Stereo Sound of it.
    Give a Suitable Power Supply 2* 150 = 300 W.

  196. Vijay Kumar

    Sir. I am a student of jetking. I extreamlly need a very powerful amplifier circuit diagram with bass and trable control with supply 12v though IC not transistor. Please Help Me.

  197. There could be some simple mod’s to keep this little amp more stable, even adding a componet to bridge this little guy, 300w @8 ohms… more so led bargarth to show power out put and a 22k log pot at the input stage as not to drive to much in put signal in and clip the o/p….

  198. Hello to all, very simple circuit indeed.
    the ’33k’s are 3k3 types, all transistor amps should have zobel rc networks to keep the amp stable. (10 ohm and a 100n cap will be fine.
    Someone did ask ‘why use diode’s this is to help bais the amp… quick psu design would be 220va transformer and filter dc caps 4700uf say 63v’s. and simple 3 second relay timer between the o/p and speaker circuit will stop turn on/off thumps.

  199. arbiefactor

    from manila.
    i just want to ask if their are any transistor that can replace for TIP140,TIP147,TIP42 and im using Multism7 for the simulation.need reply asap tnx

  200. Hi,
    iam new to this site i have seen the diagram i like it but i would like to know weather the transistors are available in the market???

  201. hi can you give me the power supply circuit diagram of the 150 watts amplifier. I don’t know the diode that i put in or the capacitor the i place in the circuits.

  202. Is it really possible to use an MJ11028 and MJ11029 instead of TIP142 and TIP147?

  203. twits4twats

    admin is correct
    4500W PMPO (peak maximum power output)is non existent and is only there to entice wangsters with mine is bigger than yours.
    If a circuit was capable of delivering that sort of power, imagine how big it would have to be. Definitely beyond the means of any body wishing to build the circuit themselves. And just imagine, if you were capable of building it, would you be able to listen to it.

  204. helloooooooo , give me a 4500w pmpo ckt ………. plzzzzzzzzzzzzz

    • admin

      PMPO is just an advertising stunt made by the manufacturer to confuse the customers. PMPO is the output that could be obtained from an amplifier with 100% efficiency at ideal conditions for certain frequencies and so on.The requirement goes long.Anyway this is absolute non sense and impractical.

      4500W is hell of power.Have you notices one thing?. The power consumption stated on the back side of a so called commercial 4500W PMPO music system or amp will be only few hundred watts. How can they produce 4500W of output from few hundreds of watt input.
      The real and practical representation of power is the power in rms (Wrms) and you need to be concerned only about the rms Wattage.

      A simple, cheap and elementary 150W rms amplifier will produce more blast than a so called 4500W PMPO amp.

      I follow the rms scale and so do my all circuits.


  206. michael ohene-adu

    The TIP147 gets warm in the absence of an input,and i noticed about 25mv at the output.what must be done to achieve 0 output in the absence of an input? please help.


    • admin

      most of these circuits are in the site.pls look out.

  208. aleksandr

    the regard,I from russia,has collected this amplifier,but with three diodes and consecutively to him resistor 22 ohm,when garbling less.
    вопрс,possible 142 147 change on MJ11028 MJ11029?

  209. Hello there
    I want to ask u , what is the maxixmum cuurent i nedd to supply the amplifier and what is the maximum output current?

    Well I build the amplifier with a + – 50v /7A and I run it , I raise the volume from my computer but the level of sound in the output of the amplifier , was not the level of sound I was expected to hear in a amplifier 150W , why is that problem ?( In this circuit I use TIP147,TIP142,TIP41 and the resistors 3.3KOhms)

    Another problem I have here , is that I only can find the resistors 0.33Ohms in 5W , is that a problem ?

    And something last I want to tell u that I saw an another circuit like yours but there has TIP41 and not TIP42 also it had RESISTORS 3.3KOhms 1W and not 33kKOhms 1W u have here . I want to know witch circuit is the right.I try your circuit with TIP42 and R=33KOhms 1W and didn’t work , then I try the other wicth uses the TIP41 and R=3.3KOhms and it worked but I had that problem with the sound.
    Plese answear my Reply Thanks!

  210. piyush patidar

    it’s very nice circuit..
    can u send me it’s block diagram of working on my e-mail id i.e. er.patidar@rediffmail.com

    i want to make it circuit as my minor project..
    one more thing, if u have any protection circuit for this above circuit then please sene me it also..

    pls help me…

    piyush patidar
    indore (india)

  211. hi..I from Philippines
    this is a great AMPS but my problem is the wattage 150W. I decided to change the TIP142 and TIP147 to MJ11028,MJ11029 darlington pair to get a 300 watts,but the same TIP41 and the same supply voltage.It is good? or working Properly?


  212. hi..I from Philippines
    this is a great AMPS but my problem is the wattage 150W. I decided to change the TIP142 and TIP147 to MJ11028,MJ11029 darlington pair and the same TIP41 and the same supply voltage.IT is good? or working Properly?
    just E-mail me.rj_john23@yahoo.com


  213. Is it o.k. if I connect the metal of the transistor to the Heatsink or in ground.thanks.

  214. i have a transformer from an old pioneer
    can i build a new power supply with it. it was a 280watt stereo so the transformer will be enough? and i think that the transformer gives -120 gnd +120 but i dont know how to build a power supply that will give
    -45 0 +45 with enough power for the 150watt amplifier, and will it be enough for 2 amplifiers.

  215. Onkel fester the childmolester

    where would it be best to put the volume controll ?
    and VU meter ?

  216. can i ask why do the tip147 smoke and wrecked when i turn it on? is there a problem of the supply, because i used 35 0 35 15 amp… or the low resistance between the two bc558 the 1.5k i used 1k 1/2 watt.. as well as the 2 resistor 0.33k 5watts only? can you help me. whats the prob? i just want to creat the amplifier. pls. thanks..

  217. Hey,i’m dare from indonesia
    = that’s nice amp. i’ve try it once,not dissappointed . but i need some with transformer output ,coz i”m working on 120 watts sirine ,can i modify this circuit?? —

  218. I try to built this circuit at home but I can’t buy 7 watts .33 ohms resistor, only 10 and 5 watts is available here our market. Can you suggest what resistor will I use.

    Reply: No problem , use the 10 W resistor.

  219. Cedric Somers

    Are the 33K 1W really 33k or 3.3k. Also, TIP 142 and 147 are darlington, you put two diodes (1N4007) to compensate the crossover distortion, because the transistor are darlington, should it be preferable to put 4 diodes ?

  220. comment : I was just curious since I don’t work with transistors that often. My background is in opamps. Is there any benefit to stacking two of these transistors in parallel? I thought possibly more headroom or faster bass response. any input?

    Ans: i don’t think there is nothing more in putting the two transistors.I am a transistor man that’s why i just included these two transistors and they are found to be OK.If you you want to go with opamp OK no problem ,it will surely provide some better low freq response
    .but have to check it .Any way I will try your suggestion soon .Any way you go with your opamp design .This is a cheap design so nothing to loose.it should work. any way best of luck.great circuits are born with experiments.

  221. jimmy:
    I am interesting about this circuit and I want to assemble it in double (for Right and left). Are there some want who knows what kind of transformer I could use to provide the power supply?
    I have looks for this one (167S64) but it is 64 volt CT 10 amps. I don’t know if the voltage is too high?
    I thing I could also try with 2 167P50 (50volts CT, 5amps) but that will be more expensive.
    I don’t know what could be the best

    Thanks for help

    A power supply for each channel is the best option,because it will reduce distortion theoretically.Here we cannot expect this because this is a cheap and simple design .
    I prefer to make this circuit as cheap as possible.I used a 45-0-45 transformer and the result was just fine.You can use up to some 65-0-65.Above that may cause some extra pressure on the transistors ,and I have not tested that much high voltages as supply for this circuit during test.You can gamble with this circuit because this is a cheap one .Any way my preference is 50-0-50.
    If you have a 65-0-65 already with you ,you can try that.Other ways a 50-0-50 will be enough.Thanks for the comment.



      will this circuit works on 22-0-22 dc dual power supply.I have seen one circuit with transistor 3773 100w in this site.Which one will sounds best please help me.Which one has low distortion.