The mini crescendo 100 watt transistorized amplifier circuit explained here was built and tested by me and am extremely pleased by its performance and also its ruggedness as far as maintenance and handling is concerned.
Amplifier Class
Basically, the entire configuration is a symmetrical class A amplifier incorporating an input filter stage, an intermediate driver stage and a powerful symmetrical output stage consisting of the versatile 2N3055 power transistors. The circuit efficiently drives a 100 watt 4 Ohms speaker with inputs derived from any audio source like a cell phone or DVD player etc.
Before you learn how to build this interesting and useful 100 watt amplifier circuit using 2N3055 transistors, a prior understanding of the involved circuit configuration would be very handy, let’s begin the explanation with the following points:
Circuit Operation
A quick glance at the given circuit diagram makes us conclude that the output configuration is not symmetrical, since the transistors T15 and T16 are both NPN types.
The input stage of the circuit begins or initiates with a symmetrical differential preamplifier stage consisting of the transistors T1, T2 and T3, T4.T5 and T6 are positioned as the current sources which are further extended as the driver stage consisting of the transistors T7 and T8.
However a closer inspection tells us that of course the wiring is symmetrical, having the transistors T11, T13, T15 at the upper section acting like special booster transistor package.Similarly the lower section also employs identical super booster stage consisting of the transistors T12, T14 and T16.
The above two sections are perfectly complementary to each other, with reference to the diagram which indicates their emitters being terminated to a common point through the resistors R25 to R27 and via R28 to R30, this effectively that the wiring is exclusively symmetrical by nature.
The output stage is able to produce a massive 200,000 times amplification factor with comparatively very low quiescent current drain.The quiescent can be set by the adjusting the preset P1.
Due to a non critical nature of the circuit, the entire project can be easily built over a general purpose PCB, however the layout of the components or rather the placement and the ratio of the distance of the components must be kept as identical as possible to the layout of the circuit diagram.
Though a common heatsink may be used for the entire set of the output devices, I personally used separate individual heatsinks for each of the transistors.
This saved me from the headache of using the cumbersome and low efficient mica isolation kit between the transistors.
The inductor is kept for improving the dynamic nature of the circuit. It is built by winding 20 turns of super enameled copper wire over the 1 Ohms resistor itself.
The wire is selected to be close to 1mm in thickness. Though not absolutely necessary, for better thermal stability the transistors T9 and T11 and also T10 and T12 should be glued together, preferably by attaching the respective pairs face to face.The quiescent current should be ideally set to 50 mA through the following initial procedure:
How to Set Quiescent Current
1) Remove the speakers, and short the input terminals (across R1),
2) Connect a DMM set at current range in series with the positive of the power supply to the circuit,
3) Next adjust the preset such that the meter reads an input of 50mA, that’s all, the amplifier’s quiescent current is set and now the connections may be restored for the normal operations of the system.
Power Supply Circuit
The power supply circuit is also shown along side and as can be seen there’s nothing special about it and may be built using the shown ordinary sets of components.
Parts List of 100 watt amplifier circuit (sh0wn below)
- R1 = 430 K,
- R2 = 47K,
- R3 = 330 Ohms,
- R4, R5 = 12 K ,
- R6, R7, R20, R21, R22, R23, R24 = 1 Ohm, 3 Watt, Wire Wound Type,
- R8, R17 = 68 Ohms,
- R9 = 100 K, R10, R11, R12, R13 = 5K6,
- R14, R15 = 12 K,
- R16, R19 = 100 Ohms,
- R25 = 10 Ohms / 2 Watts,
- P1 = 100 Ohms Preset, Linear,
- C1 = 1 µF / 25V,
- C2 = 1 n, CERAMIC,
- C3, C4 = 100PfC5 = 100 nF,
- C6, C7 = 1000 uF / 35 V,
- L1 = 20 turns of enameled 1mm copper wire over R24,
- D1, D2 = RED LED 5mm, All other diodes are = 1N4148,
- T1 = Matching BC546 pair,
- T2 = Matching BC556 pair,
- T3 = BC 557B,
- T4, T7, T8 = BC 547B,
- T5, T12 = BC 556B,
- T6, T9 = BC 546B,
- T10 = BD 140,
- T13 = BD 139,
- T11, T14 = 2N 3055
- General Purpose PCB,
- All the transistors T10, T13, T11 and T14 ae mounted on suitable heatsinks
The original design, (courtesy - elektor electronics)
The Mosfet version of the above design can be witnessed in the below given image:
For the complete construction details, please refer to the following link:
Mini Crescendo pdf with PCB and protection circuits
Video of the Crescendo Amplifier showing the PCB Design and the Component Layout Details, along with the Complete Test Report:
Contributed by Mr. Siva
Rabiu Ibrahim says
Dear sir please can I add more 2N3055 output transistors for more output power ? I need strong bass even in a low volume is this possible to add thanks so much
Swagatam says
Hi Rabiu, I don’t think that is possible, you can’t use more number of 2N3055s to increase power in this circuit.
For powerful bass you can try adding the following circuits:
https://www.homemade-circuits.com/?s=bass+sub
Partha Mazumder says
Hi, Swagatam,
Could you please send me the PCB. It will be of real help. Thanks
Swagatam says
Hi Partha, you can get all the details along with the complete PCB design under this link:
https://www.scribd.com/document/502160871/37172068-e014036-155
Ravi Sharma says
Pls give me 6 pair 2n3055transister amplifier circuit diagram and pcb pdf and transformer voltage and amp.
Vasile says
What are the values for R26, R27 and R28? They seem to be added in the schematic later.
Is the schematic at the latest version?
Swagatam says
All the schematics are correct and working.
Those resistors are 1 Ohm 1 watt
jayanath says
Dear sir is this suitable for public address loudspeakers? if yes which circuit should i make?
Swagatam says
Jayanath, it is suitable, but megaphones do not require H-Fi circuitry therefore can be built with cheaper designs….the above design can be quite expensive for a crude PA audio system
Sarbjit Mal says
Hello Swagatam. While I was considering to construct the mini crescendo original ckt design as published by Elektor Electronics in its Elektor India august 1991 issue titled as “40 watt main amplifier”, I luckily came across your this tutorial where this original ckt have been reproduced. I noticed that to improve the performance you have made some modifications to the original ckt at the input RC network, replacement of zener diodes with LEDs in the constant current circuitry and feedback components. It is evident that you have tried/ tested the original as well as the modified ckt and noticed the improvement in performance parameters. I would like to know to what extent the improvement in terms of frequency response, harmonics distortion, output power, input sensitivity(mV) for rated output(improved, if any). This will help me to decide which ckt I should go for i.e. original or modified. I also noted that the modified ckt uses the same power supply as that of the original ckt. Further, I am sure that you might be having performance parameters as mentioned in the original ckt article published in elector magazine. Still for my satisfaction I am mentioning some of these as below:
i) Output power 40 Watt into 8 ohm, 60 watt into 4 ohm for a distortion not greater than 0.01% over frequency range 20Hz – 20kHz.
ii) Max power at onset of clipping is 45 watt into 8 ohms and 65 Watt into 4 ohm load.
iii) Input sensitivity 800(850) mV for 40(45) watt and 700(750) mV for 60(65) watt into 4 ohm load.
iv) Frequency response 15Hz – 100kHz within 1 db.
Therefore, I would like to know about improvement with respect to above mentioned parameters.
Further, can we expect some further improvement by replacing the 2N3055 connected to -Ve supply rail with MJ2955 PNP transistor ofcourse along with corresponding changes in biasing network to make it fully symmetrical with the upper half ckt around driver and 2N3055 power transistors connected with +Ve supply rail.
Waiting for early response from Swagatam. Thanking you in advance.
Sarbjit Mal
Swagatam says
Hello Sarbjit, All the circuits presented in the above article were taken from Elektor electronics magazine, none of them are mine or modified by me.
Since these are from the elektor magazine all are perfectly tested and working designs.
The last design is an upgraded version of the first designs and is rated to work from 250 watts to 300 watts.
I have little idea whether these circuits can be modified using pnp transistors or not, I recommend not to do it since the original designs are well optimized for best performance.
Nagarajan says
Sir,
Could you please leave your suggestions for the following:
I have made 100 + 100 Watt amp using 35-0-(-)35 V Dc.
Can I drop the DC voltage from 35 V Dc to 12 V DC.
And this circuit will work in 35 Watts power in good condition.
Thanks.
Swagatam says
Hi Nagarajan, you can do that! It will work as suggested by you!
Mihir says
Thanks for such a perfect tutorial….. I made with your guidance of this post…. Here is the video link for my working amplifier….
Damir Popovich says
Please send me the PCB diagram. My email dpopovich@sio.midco.net
Thanks. Damir Popovich
Siva says
I built this circuit (in the end) by making the PCB with DipTrace (Used LEDs instead of Zeners). Its working marvelously with Technics Speaker Boxes (as my Technics SU V303 was condemned) Swagatham Sir…. Thank you very much for publishing such a great circuit.
Swagatam says
That’s amazing Siva, could you please send a small video clip of your work to my email? I can compensate Rs.200/- for it….
if only it is possible… not a force…keep up the good work!
B. SIVA KUMAR says
Sir,
Please send your email. I have made a video and send you the same.
Swagatam says
Siva, you can send it to
homemadecircuits
@
gmail.com
Siva says
Sir,
I have sent the video to the above email.
Swagatam says
Hi Siva, I’ll check it soon and let you know!
dg says
This could not work with the schematic with that black bg as is. Like I said. Just take a look at T14 for example, B-E junction? Can’t anyone see anything fishy there?
Swagatam says
It’s probably a drawing mistake from me, I have corrected it now, two of them will be 680 ohms and the other one 100 ohms
dg says
the copied schematic on the black bg is wrong. don’t use as is
no pcb layout?
Swagatam says
PCB is not strictly necessary if the assembler knows how to solder components on a veroboard. The first design is also correct, it just has a slightly different configuration compared to the last one. All these designs were tested by elektor electronic engineers.
The last design was built by me on a large veroboard and it worked at the first instant.
dg says
elektor’s crescendo was a mosfet amp, not a bjt based one.
and this amp is about 50w (on 8 ohms) not 100w, unless it’s on 4 ohms, and then not enough outputs are there and it will eventually blow if pushed a little too much.
one pair of 3055s on a complex 4 ohms load is asking for trouble.
pushing the rails above 35V is also pushing the limits as well, unless the 3055s are the most recent made, then they may stand up to some more Vce, but it would be wise to test them for secondary breakdown before using them on rails above 35V
Damir Popovich says
Hi Lancy, will you please send me those PCB designs? My email is
dpopovich@sio.midco.net .Thank you.
Dowe says
Hello. I am trying to simulate this circuit on microcap and it seems nothing is working. Output is just some nonsense, I think I’m making a mistake that I cant figure out by myself. It really bothers me, Also tried it on Altium. If anybody could help me with that I would be really grateful.
Just write my an email if you decide to help. dowe892@gmail.com
Swagatam says
Hello, please try the one which is shown at the end of the post…the design has been practically tested with awesome results.
rjegadeesan says
fine circuit. can u send pcb diagram .thank u
Swagatam says
thanks, If possible I’ll try to upload them soon…
rjegadeesan says
thank u swag.i am very u very much interested of the nice circuit.can u explain why u have included two stage of differential pre amplifying with 547 etc .will one stage pre amplification not it be sufficient adding more stages complicates the circuit .will u give some explanatory note of significance of different pre amplifier transistor ,thus it will provide full understanding of amp circuit working.
Swagatam says
thanks Jegadeesan, however I will not be able to explain the details in-depth because amplifiers are difficult to simulate in mind.
Basically the T5/T6 section becomes the constant current source along T1/T2 which supplies the required power to the driver stage T7—T10, while the remaining stage comprising of T11–T15 forms the power amplifier output stage….:)
Unknown says
Can u send the soft copy to my mail id shijuc1921@gmail.com pls
Japi Roño says
Can this circuit can be inserted with a USB slot?
Swagatam says
if the USB slot is able to produce the required minimum level of soundsignal input then the amplifier will work with this input source
lima toshi says
Hello Swagatam, i love to try this amp out because i have four 2N3055 just laying around doing nothing(: but sadly this transistors "BC546, BC556, BC557B, BC547B, BC556B, BC546B" are no where to be found on Indian e-commerce sites, so can you please give me an equivalent replacement for the transistors.
Thank you.
Regards.
Swagatam says
Hi Lima, The BC546, BC556, BC557B, BC547B, BC556B, BC546B transistors are one one of the common types of transistors that one can find in any market….it's surprising that you could not find them anywhere….in my place these can be procured in bulk.
anyway you can use any 100mA or 200mA rated transistor having a 100V as the max V rating in place of these BJTs.
Biman Mandal says
I don't remember the specification of these transistor.
but the circuit was +22 0 -22 volt dual supply (with 18 0 18 CT 3Amp transformer) Can I use 2N3055-MJ2955 ?
Swagatam says
you can try it but 2N3055-MJ2955 look overrated, you can try TIP31/TIP32 instead
Biman Mandal says
I was Constructed a 30W+30W Cassette Deck very long ago, using N055 & P055 Transistor in Golden PCB (Gemini Radio, Chadni Chawk). I get the Circuit diagram from a book of Debashis Bandhopadhyay (ERC publication). Recently all Transistors are burnt out but, I want to repair the Amplifier. I have lost the book. I did not find the Transistor or Circuit Diagram in Gemini Radio. Please give me the circuit diagram of the amplifier of N055-P055. And suggest me where can I find the Transistor or it’s substitute.
Thanks in advance.
Swagatam says
Please provide the approximate number of transistors and their sizes (package) used in your design, this will help me to identify a similar kind of circuit for you:
Biman Mandal says
There are total 8 Nos of Transistor in a single side. 3 Nos BC548, 3 Nos SL100/sk100 and Two power transistor one N055 and one P055 (N055 and P055 are like 2N3055 package TO-3)
Swagatam says
It would be difficult to find the exact equivalent of your version, nevertheless you can try the following design
/blog/2017/01/simple-300-watt-power-amplifier-circuit-using-transistors.html
you can use only one pair of transistors at the output stage instead of the shown 3 stages.
Biman Mandal says
Can you please suggest me equivalent/ substitute of N055 and P055
Swagatam says
please tell me the voltage and current specifications of these transistors, because these are obsolete parts now and no info is present anywhere.
Gurbakhshish Singh Saini says
This amplifier is the modified version of the original 40+40w amplifier circuit by MD Hull a pioneer designer for Philips nv Netherlands. The circuit has very good bass and treble at very low volumes. I built this amplifier completely as per instructions ( book was published by Norman Brothers in India) in 1990 and is working perfectly to date. I had used only with modification of bd182 with 2n3055. The bass and treble control and the preamp were build and used as were given in book. The bass is far better than the now days used driver driven subwoofers. I had used 0-54v transformer 3A (guru make), dome tweeters*4 of Philips, mid range of 80w and woofers of 10 inch Bolton make with cross over. This whole audio system cost me around 8230rs in 1990's. But believe me even Bose or marantaz or sonos does not compete with it any way in any frequency levels. The bass and treble is very good.
n
By
Swagatam says
Thank you for this interesting update!!
Ivan Vukic says
Whats the max input(audio) RMS voltage?
Swagatam says
you mean minimum, it's 100mV
Ivan Vukic says
No, i mean how much is needed to achive the max power
Swagatam says
anything between 100mV and 500mV will be enough to get maximum output power
Bob says
how about these sanjeev…C2073 and A940.
arheem aly says
i have question please it can work on 12 v dc ?
lan says
Tip 3055.
SANJEEV FRANK BROWNE says
2N3773 IS better to use
Mr. SANJEEV FRANK BROWNE says
Dear BOB
For driver stage transistors BD139/140 can be replaced by 2SC2073 and 2SA940 but it better to use MJE350 and MJE340
Ivan Vukic says
I have made this apm on a protoboard…and for the love of God i cant make it work…the input just gose to the speaker with no amplification and the amp draws 2A, i have used the undmodified circut…i have used bc557c and bc447c insted of the b version, is that a problem?Suplly is +-25V
Swagatam says
BC447 is not the problem unles it's faulty…the circuit is huge and the fault could anywhere in the design.
the quiescent current consumption of the circuit without load should be first set to 50mA
this is done by shorting R1/C1 junction of the amp to ground, speaker connections open, ammeter connected in series with the ground line, and P1 adjusted until the meter reads 50mA
Ivan Vukic says
i'll try it on a proper PCB, then we'll see if it works..
Rafael Cordano(1BC UTU) says
Hi,
could you upload the pcb layout o send it to me to
Thanks
Bruno Ausmann says
Hi, can you tell me the brand model of this circuit please ? , thank you
Bruno Ausmann says
Hi, I saw this circuit a long time ago, but didnt had the time to actually do it, my question , is the schematic good ? ( i read here that the 2nd photo has some drawing mistakes ) and whats the name/model of the Amplifier, i heard it's crescendo. I have a couple of 2n3055 made in 88" ( i think they are better then the new ones ) also , its the 2n3772 " better " or at least can be used instead of the 2n3055 in this circuit ?, Thank you, sir !
Swagatam says
Hi Bruno, The circuits are perfect! and will work no matter which one you build.
2n3772 is good, and can be used instead of 2N3055
lan says
Hi Gautam Kumar Goswami.
Sorry for the delay. PCB softcopy diagrams posted dude. Enjoy.
Lancy Felix.
Gautam Kumar Goswami says
Please send me the soft copy of the PCB layout to my email: geotek_co@yahoo.com
Christian Beltrami says
good evening beautiful project . it would be possible to have the technical data of the amplifier ? is it possible to have the PCB soft at chri3399beltrami@gmail.com?
thanks christian
Swagatam says
thanks, you can refer t the following pdf for more details:
raylectronics.nl/pdfs/Crescendo_Millennium_en.pdf
Rajiv Telang says
Hello sir. I am constructing this amplifier. Please send me the pcb layout at telangrajiv@gmail.com
Rajiv
Gautam Kumar Goswami says
Hi Lancy Felix, my name is Gautam Kumar Goswami & I am a Hi Fi Buff. I want to build this 2N 3055 based 100W power amp. Kindly send the PCB diagram soft copies to my email id : geotek_co@yahoo.com
Thanking you in advance,
G.K.Goswami
Gautam Kumar Goswami says
Dear Mr. Swagatam Majumdar, I want to build this amp & for this I need help from you. One is the PCB in soft. Can you please send it to my email id ? I also need a suitable preamp & tone control unit suitable to its specification. My email id is : geotek_co@yahoo.com
Swagatam says
Dear Gautam Kumar Goswami, you can find all the details in the following article:
http://www.eeweb.com/project/circuit_projects/300-watt-mosfet-real-hi-fi-power-amplifier
Gautam Kumar Goswami says
Dear Mr. Majumdar, I requested for the output 2 x 2N3055 based 100W amplifier PCB in soft & its current upto dated circuitry. Please help. My email is : geotek_co@yahoo.com. Thanking you in advance,
Swagatam says
oh..sorry, it's not available with me at the moment…
Gautam Kumar Goswami says
Please send me the PCB diagram. My email is : geotek_co@yahoo.com
Marigold Myka Lawas says
Is this a 2.1 amplifier? Or just mono?
Swagatam says
It's a mono amp…you'll need of these to get a stereo output
Gautam Kumar Goswami says
I am an audio buff. Can you please send me the soft copy of its pcb to geotek_co@yahoo.com ? Please help.
Abinash Das says
Please Swagatam Sir, Kindly upload corrected diagram for error free and last long daily use of this project.
Swagatam says
Hi Abinash, who said the diagrams were not correct?…both the diagrams are perfect, however the last one has been tested by me…so you can try that.
Abinash Das says
Thank you Swagatam Sir, for your quick reply. Please give your email id for share some valuable information with picture about this project. I will expect support like that from you in future also.
Swagatam says
Abinash, commenting in the my website is the best way to get in touch with me without fail….for image presentation you can submit it to:
admin @ http://www.homemade-circuits.com
Abinash Das says
Good Evening Swagatam Sir,
If possible, can you please upload a video in youtube of 2N3055 amplifier you have already made in the year 2000. So we can able to hear sound quality of this Class A amplifier.
Swagatam says
Good morning Abinash, sorry that won't be possible because it was built and used by me a long time ago, and was later dismantled for some other purpose
Gautam Kumar Goswami says
Hi Khushin Makim, please send me the sof copy of 100 2N3055 PCB. My email id : geotek_co@yahoo.com
Thanking you,
Gautam Kumar Goswami
Anwar Saeed says
please send me the above pcb diagram at anwar621@gmail.com
Aaronz Paul says
Hi thanks for the info,actually my aim is to build a HI-FI 5.1 home theater system (100 watts in each channel if possible) with tweeter + mid range speakers in 4 of the channels and the rest would be center and sub.So pls advise me what circuit would be the best for this….thanks in advance.
Swagatam says
You can try the following simpler design, it also has been tested by me:
https://www.homemade-circuits.com/2012/04/how-to-make-simplest-100-watt-mosfet.html
Aaronz Paul says
Hi, I would like to know if this circuit is used for creating 5.1 channel amp then how many transformer is needed……in other words how do u power this amp
Swagatam says
Hi, you could use the above circuit along with the following one for getting a proper 5.1 implementation
https://www.homemade-circuits.com/2012/08/exploring-ic-tda-7560-4-x-45w-quad.html
Swagatam says
the amp is powered from the shown power supply design and the signal input is acquired from any music system headphone out
joseph aliman says
good day can i use a 18-0-18v, 6amp transformer for this amplifier, thanks
Swagatam says
yes will do…
dch says
Can I build this without any printed circuit board? Or is printed circuitry required?
It is suggested to stick to diagram layout yet two pairs of transistors are suggested to be glued together. They are in widely different parts of the diagram. How to do this? 'Fold' the circuitry up? Or have long leads to the transistors, putting them above the rest of the circuitry.
This will be a first project ever for me.
🙂
Swagatam says
yes you can do it, because I myself built it on a dot matrix PCB and succeeded in the first attempt…refer to the diagram that's given in the bottom of the article, I think the transistor glueing info may not be correct so don't do it, I'll check and update the correct data soon.
Swagatam says
OK..the transistor glueing instructions is relevant to the last diagram…I hope you won't have to fold the PCB now:)
Evo Khyn says
okey sir. thanks a lot. ill notify you for an update.
Evo Khyn says
sorry sir but im new to potentiometers. should I use the center terminal and one outer terminal?
Swagatam says
the center lead is the important one, the other one could be any one of the outer two leads.
Evo Khyn says
and lastly sir, this is the schematic diagram which my classmates used. is this the same?
http://www.brighthubengineering.com/diy-electronics-devices/94189-make-a-100-watt-transistor-amplifier-circuit/
Swagatam says
yes it's the same circuit
Evo Khyn says
we are also using 100ohm preset trimmer with the middle pin connected to one of the front pins.
Swagatam says
that's fine…
Evo Khyn says
Good day sir. We already made the amp but without the inductor first because we didnt have the chance to buy today. We have a little problem. the sound was too low. like there was no amplification. but we used a mono jack to connect to our cellphones. maybe it was the problem. or is it something else? we are so close to finishing this project. is there something we can do? we will try to use a 3 pin stereo jack tomorow and short the left and right. will it be okay? thank you sir.
Swagatam says
Good day Evo,
do not connect any music at the input just touch it with your finger, it must produce a very loud buzz in the speaker, and a small hisss when the finger touch is removed…..if this is not happening surely there's something terribly wrong with your circuit assembly.
I built the second design in the year 2000 when I was quite new to electronics, yet I succeeded to get the best response from it at the first attempt….i had used a general purpose board…not even a PCB
Swagatam says
mono or stereo input is not the problem…the problem is surely in the amplifier circuit itself….
Swagatam says
by the way make sure to set the quiescent current with the help of the given preset in the amp….otherwise the circuit will waste a lot of power unnecessarily.
Evo Khyn says
yes sir. i can hear a buzzing sound but not that loud. and i can also hear a little hiss when i turn the amp on. but the sound is not that loud.
Evo Khyn says
and can the V+ and ground terminals of the P1 interchangeable?
Swagatam says
it should be very loud, the vibration on the speaker cone should be very high and visible to eyes…something may be not correctly done or the components may be faulty
check and set quiescent current as explained in the article.
Swagatam says
presets do not have polarities, just use the center lead and any of the outer leads of the preset for the connections….. anyway round…the other outer lead can be left open or unconnected
Evo Khyn says
Okay sir. Thanks a lot. I'll notify you as soon as the amp is done.
Evo Khyn says
i think the line is an excess sir. thank you very for your help.
Swagatam says
the extension from R12 ground towards left is a drawing mistake, rest everything is correct in the first diagram.
Evo Khyn says
Good day sir. I already decided to make the original version and currently building it. My only concern is that my transformer is only around 21-0-21 and after the rectification it goes up to 28-0-28. It would be good to the new amp design but in the original it indicates around 30 to 35v input. Im a little under voltage. Will this be a problem?
Swagatam says
Good day evo, there won't be any technical problem if the voltage is decreased, the wattage of the amp will decrease proportionately…. that's all .
Evo Khyn says
thank you very much for your help sir.
I would also like to inform you that my classmates had a problem with the new version of the design. the LED on the upper part wont turn on, T13 explodes and C7 is connected on the wrong terminal. The first time they turned it on, C7 exploded. I think its because the positive terminal of the capacitor is connected to the negative of the power supply.
That's why I decided to make the original version. I'll also update as soon as I finish this project. Thank you very much sir Swagatam.
Evo Khyn says
One last thing sir, in the original design, there are C3, C4 and C5 connected in parallel with 820nF each. We have a difficulty in resources here so I cant find an 820nF. But when the three are added, they will have a sum of 2.46uF. The nearest capacitance I can buy is 3.3uF. And I have no choice but to change the three capacitors with one 3.3uF. Im just not sure if this is still okay. I apologize sir but I'm new to this. You've been a great help.
Swagatam says
Evo, the new version is also correct except C7 which needs to be reversed and R12 ground side short, except these two drawing mistakes all seems right in the diagram.
connecting 3 in parallel will have other benefits but you can also try a 3.3uF instead it would do any harm.
Evo Khyn says
Good day sir. I used 4 capacitors for the parallel connection with 560nF. their result will be closer to the sum of 3 capacitors of 820nF. I havent tried it yet coz I have a difficulty having the result of 4-6uH for the inductor and my potentiometer broke. thank you for your help sir.
Swagatam says
Yes it will do…
for the inductor simply wind any moderately thick magnet wire over the resistor itself….wind 20 turns.
Evo Khyn says
do you mean i'll put the inductor on top of the resistor? or wrap the resistor? sorry sir coz im a little confused. then connect their legs in parallel. thank you sir. I still have to wait until monday to resume making the amp. thank you very much sir for your non stop help.
Swagatam says
yes that's right, wind the copper wire directly over the resistor and then solder the leads (resistor and the coil) together across the given PCB holes.
Evo Khyn says
this part sir, at the picture. the horizontal line.
http://www.4shared.com/photo/D7dy-2CJba/amplifier-100-watts.html
thank you for the response.
Swagatam says
Evo, please go with the following diagram, it's the original one and is more correct:
4.bp.blogspot.com/-6H3usY45JAM/UThb0mHH85I/AAAAAAAADdU/wNpmxml3ph8/s1600/100+watt+amplifier+circuit.jpg
Evo Khyn says
good day sir. I am currently making this circuit. I just have a question. At the bottom left, is there really a connection under R12? I just notice that there was an excessive line going to the left and it is not like the one on the top left. I am just confused because if they are really connected, then the non-connected lines between R14 and R19 are useless. Can you please clarify sir? I will wait for your response to be able to continue the build. Thank you.
Swagatam says
good day Evo, i can't see any extra line anywhere, R12 and R11 rails seem exactly symmetrical…did you click the image to enlarge?? please click it to enlarge.
R14 and R19 are wide apart, they have no link at all…I hope there's some confusion in reading the diagram from your side…enlarging it will clarify it
Evo Khyn says
Good day sir. Could you please send me a copy of the PCB layout. Thank you very much.
evokhyn@gmail.com
Evo Khyn says
And I also noticed the power supply circuit. Is the output going to be 25V/5A? Coz I can see a 30V on the bottom left. thank you sir.
Swagatam says
power supply outputs will be +25 0 -25V dual supply but after rectification it could well become +32 0 -32v
Bhupender Dhawan says
Hi Swagatam sir
please send me the above pcb diagrams.
my email id: bhudha@gmail.com
Admin says
can we use tip or mje 3055 in place of 2n 3055 and which will be better
Swagatam says
will require too many modifications,…
Admin says
Is it possible to convert a existing 2n3055 based amplifier into a mosfet one.
Admin says
can we use MIC 6A4 diode in power supply.
panzac5 says
Hi from Athens, could you please send me the PCB layout for this amplifier.
My email is panzac5@gmail.com
Thank you very much
Swagatam says
sorry, PCB layout is not available…….
kanagaraj kanagu says
sir i need regulator power supply for luxion 1watt led i want to connect 8 led's input voltage 24v
Swagatam says
use the following circuit
https://www.homemade-circuits.com/2013/06/universal-high-watt-led-current-limiter.html
kanagaraj kanagu says
thank you sir
Jannick Svejstrup says
I adjusted the P1 with an multimeter in series with (+) to the power supply, but no matter how much I djusted the 100Ohms preset, it only showed around 3-5mA
Swagatam says
there's something not correct in your circuit, check all the connections many times you should be able to locate the fault…I built this circuit some 10 years ago and succeeded at the first attempt.
Jannick Svejstrup says
Hi again
I have built the amplifier, and i am getting an amplified signal out of the speaker, but it is very quiet, and a bit distorted. I tested the voltage over all the tranistors, and its at approximately 35 volts, except the T7+T8 – they are only showing between 0,1 – 1V. What could I be doing wrong?
Swagatam says
No, there's definitely something hugely wrong with your connections or the parts.
Once built and set the output should provide a large amplification, even without any input music you should be able to hear a big Hiss on the speaker.
did you adjust the quiescent current as suggested in the article??
bmx64x says
hi Lancy Felix
is it possible for you to send me a pcb layout for this amplifier?
my email address is ttararo@gmail.com
much appreciated.
lan says
posted dude.
bmx64x says
Hi guys, could you please send me the PCB layout for this "Crescendo" amplifier. My email is ttararo@gmail.com.
THank you in advance..
Jannick Svejstrup says
So, ff I measure between;
+ & 0 = 25V
– & 0 = 25V
+ & – = 50V
Correct? 🙂
Swagatam says
correct!
Jannick Svejstrup says
Okay, thanks again 🙂
Jannick Svejstrup says
This looks like a very nice amplifier, thanks for the detailed schematic and items list! I have just ordered the components and I'm excited to get started!
I have one questin though – I can't seem to figure out the recommended power suppy voltage/current. I'm confused with the shchematic sayin "Tr1, 2 x 25" Do I need a dual transformer, or?
If I only need one, will 30 Volts at 5 Ampere be suficient? Can less do it?
Im planning on winding my own transformer, so no need for "standard values" 🙂
Swagatam says
Thank you!
The transformer needs to be a center tap transformer, that is with two sets of winding on the secondary, rated as 24-0-24V at 2amps or more.
you can use a transformer rated at 30-0-30V/2amps also.
Jannick Svejstrup says
Thank you very much. If I want to make 2 of these amplifiers, one for each channel, can i just make two identical amps and ground them to the same "0" on the transformer (offcourse with twice the current), or do I need 2 seperate center-tapped windings with their own respective "ground/0"
Swagatam says
separate power supplies won't be required, you can use the same supply, just by making the grounds common…
Swagatam says
(+) ans (-) supply lines will also need to be joined as common rails for both the units….
Pramod Manuja Wickramasinghe says
how can i contact you for a personal matter immediatly pleaseeeeeeeeeeee
Pramod Manuja Wickramasinghe says
in our city there was a young man. he makes subwoofers in home and sell them. but i dont have money to buy that. he has many types of subwoofers. like 5.1 , 2.1 , 7.1. now he is not here. but i want to make one. quality bass sound subwoofer circuit diagram. thats what i need. if you have that send me. i will give my email. thankz
Swagatam says
presently i do not have it, i'll try to post in soon and let you know.
Pramod Manuja Wickramasinghe says
ow do you have above amplifire pcb diagrame?
Swagatam says
sorry, presently the pcb design is not there with me…
Swagatam says
I have seen your link, yes you can use it with the above circuit
Swagatam says
…and please do not include external links, i'll just keep deleting them.
Pramod Manuja Wickramasinghe says
do you have is there any subwoofer circuit schematic. if you have please send me. Because i want a good bass. thats what i like
Swagatam says
I'll try to include it soon in this blog and give you the link….
pramod anuja Wickramasinghe says
what is the correct swg for the L1 coil
Swagatam says
20SWG
pramod anuja Wickramasinghe says
is there a good quality bass in this amplifire.
pramod anuja Wickramasinghe says
please tell me
Swagatam says
No, it does not include bass control, you will have to add it externally
Pramod Manuja Wickramasinghe says
no no I mean the sound. can i get a good bass sound from this
Swagatam says
you can get god bass only after including a bass/treble circuit at the above amplifier input
pramod anuja Wickramasinghe says
i00.i.aliimg.com/photo/v0/309836240/TIP3055_Power_NPN_Transistors_ST.jpg
img.bhs4.com/fa/d/fadf150f65b8acbacfb586f7ab802d0a80dced83_large.jpg
checkout this links and tell me the witch transistor is good for this circuit. please some one send me the PCB soft copy. upload that and give me the download link.
Swagatam says
as mentioned in my previous comment, both the transistors are good and rated almost equally, it depends which one you prefer as per your convenience.
pramod anuja Wickramasinghe says
i00.i.aliimg.com/photo/v0/309836240/TIP3055_Power_NPN_Transistors_ST.jpg
then can I use this transister
Swagatam says
yes you can use them, be sure to add large finned heatsinks to them
Swagatam says
The value of L1 has been updated in the parts list.
Pramod Manuja Wickramasinghe says
please some one send me the PCB soft copy. my email- manujamicro1@gmail.com
Pramod Manuja Wickramasinghe says
can you send PCB soft copy to my mail:- manujamicro1@gmail.com
Pramod Manuja Wickramasinghe says
can you post a completed circuit with all parts
Pramod Manuja Wickramasinghe says
there are 2 types of 3055 transistor. first one is 2N3055 and other one is TIP3055. TIP3055 is a big transistor. 2N3055 is like a normal transistor. which one is good for this amplifier. I cant understand the L1 . How can i make it in home. I'm stuck in this plese reply me soon.
Swagatam says
Both the transistor types are almost identical with their specifications, only the package is different.
You can use any of these as per your convenience….I have updated L1 data in the parts list.
sagar rathi says
Would it be okay if i use all the smd component instead of through hole component ,can my circuit behave diffrently under smd components ????
Please answer ……
Swagatam says
yes you can use SMD, the circuit will work perfectly with them too, no issues.
Swagatam says
That's great support Lancy, Thanks very much.
Swagatam says
Don't use passive filters, use active filters as it will enhance the effects rather than deteriorating.
You can use the circuit IC2A/B section of the circuit shown in this link, use it in between your amp and music input:
https://www.homemade-circuits.com/2012/01/how-to-make-your-own-active.html
kanagaraj kanagu says
what is the different between digital ground and analog ground and how to joint these two grounds
Swagatam says
it's a big explanation, cannot provide it here….these grounds are intended for providing discrete paths for analogue and digital signals, they should not be joined.
kanagaraj kanagu says
sir i want buffercircuit & bass boost circuit using op amp
kanagaraj kanagu says
sir hoe to cut below 80HZ in low pass filter circuit
Swagatam says
By carefully adjusting the 22k presets.
Swagatam says
Hi Kanagaraj, You can make this circuit:
https://www.homemade-circuits.com/2012/02/how-to-build-automatic-6-volt-12-volt.html
replace the feedback 1K resistor with 100k pot and remove the series 1N4148 diode.
kanagaraj kanagu says
sir i want one automatic battery charging circuit (12v) i want that circuit automatically sence low battery and start charging and cut the charging when the battery is full
kanagaraj kanagu says
sir hoe to increase left right bass depth without using tone controles (only using pre amplifier) if you have any circuit like that give me
Swagatam says
You can replace the preamplifier with this circuit, it will work as both preamp and low pass filter:
https://www.homemade-circuits.com/2013/06/make-this-low-pass-filter-circuit-for.html
kanagaraj kanagu says
do you have any sub woofer pre amplifier circuit for this power amp if you have mean's wiil you please send me (kanagarajbe114@gmail.com)
Swagatam says
You can use the following circuit, just add a low pass filter at the input of the amp:
https://www.homemade-circuits.com/2012/04/how-to-make-simplest-100-watt-mosfet.html
kanagaraj kanagu says
Thank you sir,and i want single supply transistor power amplifier circuit I have o-24 transformer 5amps
Swagatam says
I am sorry kanagaraj, I do not have any such circuit presently in my blog, I will try to update it if possible soon.
Swagatam says
Thanks for the help Lancy, keep it up mate:)
sudesh singh says
Sir,
I want to made this audio amplifier circuit. But in the amplifier circuit you show the 25V supply and in power supply circuit there is 30V.
What is co-relation between them. secondly, I want to known the rating of center tap transformer you have used.
Sudesh
Swagatam says
After rectification the voltage may rise upto 30V, but it won't be a problem because the amplifier can handle upto 40V