I have been watching youtube videos on electronics for years, but I have never seen anyone explain the operation of amplifiers as clearly as you. For the first time I actually understand how an audio amp works. Well done and thank you.
Ive tried to understand how these amplifiers work for awhile now and usually shut a video off shortly after starting because I'm lost. Your video has been the best and I finally have a clear understanding of how class A, AB, and B work!
I am sure that you are a treasure for me in the science of electronics, because no one can explain like you. The only obstacle is that I do not understand English, but thank God this video is translated into Arabic. I hope that all your videos will be like this. Thank you very much, creator of electronics. Thank you very much.
Beautiful video ! In addition to the technical content, I would add that your clear way of expressing yourself and your slow pronunciation is of vital importance to me, since I am Italian. Well done !
No doubt the best explanation on the net. Most are too superficial, you do a great class, white board and then actual build and test. Keep at it, making videos is tough, subject matter tricky. Awesome work. Thanks
Brother Your explanation is the best about amplification of these 3 classes across the youtube perhaps in globe too..I became a fan of you by watching your video and subscribed channel ... love from India ❤❤❤...
Seriously, I am not an engineer or anything just like audio stuff and can do only do minor repair to vintage stuff with a 50/50 success rate. But this really allowed me to understand very basic concepts in a much more concrete way. Just the right amount of detail. I feel much more confident adjusting and checking bias on old equipment and understanding how to use a ‘scope for it. Now if I can only figure out why two resistors just went up in smoke on my old turntable…
I like the way you built the prototypes. Could you go over some techniques for building circuits using one side copper boards (as a suggestion for a new video, if you haven’t done it already)? Thank you!
May I ask a question? At 24:11 you say that it'd have 0,7v across each resistor but the total voltage would be 1,2V. Why? Wouldn't it be 1,4v? And after when you consider the trimoot with 2k ohms, it is 0,7v , 1,4v and the results would be 2,3v? Why? Why not 2.1v?
15:53, I am a little confused because I always thought that class A was a single NPN transistor (one active device) configured as an emitter follower, yet you are showing a two transistor configuration.
Class A is any configuration wheres the transistor conduction isn't cut!! It is commonly shown with a single transistor, but it's not related to the topology!
@@Enigma758 It *is* a common misconception; that exact misconception led me to find this video! I read something about Class A push-pull and I thought "Wait. How can class A be push pull?" and here it is, explained. I believe what you and I previously understood is single-ended class A.
@@AllElectronicsChannel Well then, "electronics-tutorials" must be incorrect then... "Class A Amplifiers are the most common type of amplifier topology as they use just one output switching transistor (Bipolar, FET, IGBT, etc) within their amplifier design. This single output transistor is biased around the Q-point within the middle of its load line and so is never driven into its cut-off or saturation regions thus allowing it to conduct current over the full 360 degrees of the input cycle. Then the output transistor of a class-A topology never turns “OFF” which is one of its main disadvantages."
It is not a physical correct way o saying, but it helps to understand circuits. I call a high impedance signal, the one the comes from a high impedance source. These are signals "weak", represented by high voltages with low current capacity. Low impedance signals are signals "strong", the comes from low impedance sources.
Great video Gregory! How does one go about calculating the value to be used for the Emitter resistors when building out a push pull amplifier? You mentioned you used a 3.9 ohm for each transistor, but I'd like to know how you determined that please.
Hello man! In the example I used 3.9 because it was what I had around. The resistance needs to be calculated based on the bias voltage and the bias current needed, and it needs to compensate the Vbe temperature coeficient.
👋Hello Gregory I am from India you explained very great using oscilloscope this video will help the people who are interesting in designing of complimentary symmetry amplifier. Please upload one video of push pull amplifier using high voltage mosfet like IRF 150, IRF 250 And so on
When you touch the water you create waves. When you tap it with two fingers you get resonance in different forms called amplifier. It all depends on number of holes in the lattice.
Beautiful explanation, couldn't we also use an opamp with feedback going from output to the inverting terminal and the signal coming into the non inverting terminal of the opamp
It would be interesting to see (both theoretically and in practice) how such a push-pull pair operates given a load that includes reactive components. The reason is that it's the current which matters when deciding which transistor is open, but its phase is not the same as of the voltage.
Awesome explination thank you! I am just a little confused on how the biasing network works when you use a diode to achieve your biasing. Why does the transistor also recieve a 0.7V when the boasing diode has the same. Will you please be able to explain this in a beginner way showing the cutrent flow of this system. Thank you!!
This video is just fantastic! Had to watch it a few times to absorb all of it (and probably still missing some insights). I have one question. At @30:16, what are those little current spikes (red trace) when the signal enters in cross-over? They seem to remain there also when we move to AB class.
Thank you!! Good question! It seems more like current spikes from the junctions capacitance, responding for the transients between the positive and negative cycle. Would be nice to investigate it more!
This is the best explanation I found. Thanks. I have two questions: 1) has the capacitors to be polarity dependent(electrolytic)? In such case, how we can connect the capacitor in series to the load?(is the positive pole on the load or between the two Re?) 2) are the two identical resistors in series with Vbe multiplier used to maintain reverse polarity of collector base of BJTs so that they are in active region? If so, how can we choose their values?
1) for lower frequencies, probably you will use high value electrolytic capacitors. In this situation, you connect the positive side to the transistor bridge. 2) You can calculate as a voltage divider. The bottom resistor will always have constant 0,65V, so you calculate the upper one to get the desired output voltage.
@@AllElectronicsChannel I tried the circuit. Re must be greater (10 Ohms) and transistors heats up too much after some time. With Re=3,9Ohms the transistors was damaged. I will try with bigger transistors
Hi Gregory ... Thank you very much for going by English language in this channel and your explanation on Class A , B , AB was very clear to understand the topology of these classes... But I would to ask if you can rename your channel to have " ( ENGLISH ) " word so it will be much easier for viewers to know than your original Portuguese one , you may add a link to your original channel in the DESCRIPTION for Portuguese speakers if they may be here !.... Also, Can you please correct your LOCATION country in the ABOUT page to be BRAZIL than USA ?
Hello! I`m retiring from the brazillian TH-cam as I had some legal problems and will focus only on English markets. This is now my main channel. Over time my english will improve. Thank you!
Hi again ... Even with your planning to retire your Portuguese channel , you still have to rename your new channel with good name like to mark it as " ( ENGLISH ) " and specify the location as from BRAZIL as I could not find any other electronic material channel from Brazil at all except yours and WR Kits since 3-4 years of surfing all over the world of TH-cam ... Also , I forgot to say , please put all your communication contact links in the ABOUT page with the most priority of Website URL and Email address... Great thanks for improving your channel content....
Excellent explanation Gregory! Thank you for sharing. Can you demonstrate the diode solution as a method of compensation instead of using a transistor?
Hello, thank you! I don't have any video about it now. Basically using a diode to generate the DC offset will automatically compensate for the junction voltage to temperature relationship. You need to put the diode VERY close to the transistor (in the same heatsink and side by side) so any increase in temperature of the transistor will be coupled to the diode.
Do you know how to explain op ampe 741 in internal circuit transistors working by using wave forms like you explain this..more students are waiting..please if u can
Nice Video.Could you make a video about noname toroid core's calculations values. I mean .Calculation of Al value to permability to other values and measuring effective working frequency and loses .Could you make this kind video?
I got mind-fucked! Only now I know what the heck 'distortion' and 'crossover' are in this context. I read and heard a lot about them but I do not think there is anyone else explaining them. Few of them even mention use small resistor as the bigger resistor is the more noise will be amplified. To a noob like me, it sounds magical not knowing how come resistor has noise. I am sure those 'tutorials' are meant for noobs, otherwise they will not be bothered with the babyish explanation.
@@AllElectronicsChannel The pleasure is mine! By the way, Gregory, have you any video on how to choose the 'right' values of resistor? I was understood to always choose the smallest resistor to prevent internal noise (I guess it is inherent stray capacitance and inductance. Same story with capacitor, choose the smallest capacitance possible). But again, only one person (The AudioPhool. TH-camr) I found explaining how to calculate the values, sadly he goes too fast and only transistor that he uses as the example. I mean, I would like to know how to choose resistors for an operational amplifier as well because nowadays one small chip can do a lot more, saves much more space, and prevents so much more trouble than messing with discrete devices. About noise, integrated circuits these days have extremely low noise due to everything is in close proximity and internal resistors are microscopic.
Hey guys! Don't forget to subscribe to channel to help me grow it 😁
Support the channel being a Patron
www.patreon.com/allelectronics
00
I have been watching youtube videos on electronics for years, but I have never seen anyone explain the operation of amplifiers as clearly as you. For the first time I actually understand how an audio amp works. Well done and thank you.
Glad you liked it!
Probably the clearest explanation I've ever seen. Excellent presentation
Thank you, man! 😄😄
I’ve seen this explained about a million times, but this video highlighted some subtleties that I never considered before. Well done!
This is the best explanation of class a, ab, and b that I have ever seen. Excellent! Thank you,
Glad it was helpful!
Ive tried to understand how these amplifiers work for awhile now and usually shut a video off shortly after starting because I'm lost. Your video has been the best and I finally have a clear understanding of how class A, AB, and B work!
That is great! Welcome to the channel!
Excellent teaching! Where many videos explain too little and others over complicate things, your explanations are perfectly clear. Thanks very much!
You're a natural teacher Gregory. Keep up the great work!
I am sure that you are a treasure for me in the science of electronics, because no one can explain like you. The only obstacle is that I do not understand English, but thank God this video is translated into Arabic. I hope that all your videos will be like this. Thank you very much, creator of electronics. Thank you very much.
First time on your channel. I'm amazed by the amount of devices you've got here. Outstanding!
Thanks and welcome!
Beautiful video ! In addition to the technical content, I would add that your clear way of expressing yourself and your slow pronunciation is of vital importance to me, since I am Italian.
Well done !
Thank you!! Greetings from Brazil
2 years latter, thanks for this very clear explanation, the best yet of a push-pull configuration
Thank you Edgar! Welcome to the channel
No doubt the best explanation on the net. Most are too superficial, you do a great class, white board and then actual build and test. Keep at it, making videos is tough, subject matter tricky. Awesome work. Thanks
Thanks man!!
Excelent. The most clear explanation I've ever seen about amplifiers
It's one of the best videos on TH-cam. Thanks.
Glad you think so!
Very nice explanation and example. Well done!
Thank you Gregory, I think your English is quite good. Thank you for explaining the topic so well.
Thank you !! I will be posting every week something new. Thanks for your support
Excellent explanation of push-pull amplifiers. You would make an excellent electrical engineering professor. Thanks for sharing your expertise!
Thank you!
you can not disagree with your perfection! keep teaching !
Thanks! Welcome
Brother Your explanation is the best about amplification of these 3 classes across the youtube perhaps in globe too..I became a fan of you by watching your video and subscribed channel
... love from India ❤❤❤...
Thanks and welcome
Please keep doing such great videos, your explanation was way simple and clearer than that of my professor
Thank you! What other topics would be interesting?
@@AllElectronicsChannel How about AC analysis of a BJT and Mosfet?
@@sabih1677 Really nice!! We will do it! Thanksss
Most valuable information related to understanding operating of hi fi amplifier. Great upload,,thanks a lot sir...
Thank you.
One of the best explanations ever - excellent for beginners!!!
Thank you!!
Fantastic explanation and demonstration!
Many thanks!
That was an excellent explanation and excellent demonstration.
Glad you enjoyed it!
Thanks!
Welcome!
This is so clear. Great explanation that I finally get what class AB bias vs class A nice 😊
Seriously, I am not an engineer or anything just like audio stuff and can do only do minor repair to vintage stuff with a 50/50 success rate. But this really allowed me to understand very basic concepts in a much more concrete way. Just the right amount of detail. I feel much more confident adjusting and checking bias on old equipment and understanding how to use a ‘scope for it.
Now if I can only figure out why two resistors just went up in smoke on my old turntable…
Very well explained, great job.
🙏🙏
Superb explanation. Every word was valuable. Thank you so much for this!
Thank you!!
Very good explanation. Congrats. Keep up the good work!
Thanks Tiago!
I like the way you built the prototypes. Could you go over some techniques for building circuits using one side copper boards (as a suggestion for a new video, if you haven’t done it already)? Thank you!
Thank you for this precise lecture /presentation. You have a subscriber.
Beautifully explained! Thank you so much!
this is the best push pull video , thank you
Glad you liked it!
Perfect didactic, Greg! Thank you!!!
Thanks man!
You are the BEST!!!! 😀😀😀👍👍👍🙏🙏🙏.Can you have some class talk about feedback circuits?
Did a great job in explaining.
May I ask a question? At 24:11 you say that it'd have 0,7v across each resistor but the total voltage would be 1,2V. Why? Wouldn't it be 1,4v? And after when you consider the trimoot with 2k ohms, it is 0,7v , 1,4v and the results would be 2,3v? Why? Why not 2.1v?
I think I got confused.. some times I use 0,7 and some times 0,6 as the base voltage
Absolutely incredible video thank you so much!!
Thank you! Welcome to the channel
15:53, I am a little confused because I always thought that class A was a single NPN transistor (one active device) configured as an emitter follower, yet you are showing a two transistor configuration.
Class A is any configuration wheres the transistor conduction isn't cut!! It is commonly shown with a single transistor, but it's not related to the topology!
@@AllElectronicsChannel I didn't know that, I'll bet it's a common misconception. Thank you!
@@Enigma758 It *is* a common misconception; that exact misconception led me to find this video! I read something about Class A push-pull and I thought "Wait. How can class A be push pull?" and here it is, explained. I believe what you and I previously understood is single-ended class A.
@@toadroller Nice to know I'm not the only one who thought that. Thanks for your comment! :)
@@AllElectronicsChannel Well then, "electronics-tutorials" must be incorrect then...
"Class A Amplifiers are the most common type of amplifier topology as they use just one output switching transistor (Bipolar, FET, IGBT, etc) within their amplifier design. This single output transistor is biased around the Q-point within the middle of its load line and so is never driven into its cut-off or saturation regions thus allowing it to conduct current over the full 360 degrees of the input cycle. Then the output transistor of a class-A topology never turns “OFF” which is one of its main disadvantages."
Superb, good learning. Thanks
You are welcome!
Great explanation!
Glad you think so!
More info on how to setup the scope for differential mode and why you used the mode and where you use it would help.
Superb explanation bro❤😊
Thank you so much 🙂
Thanks A Lot.This Is A Clear Explanation .
Thank you man. Great explanation! 👍
Thank you!
A video I understand clearly thank you.
You are welcome!
But on the NPN why does the positive swing go through the emitter leg? Isn't that the negative leg of the npn and the collector is the positive leg?
Read about emitter follower !
does rf Amplifier Use Class D Amp if yes than its circuit should be much faster than processing Frequency right ?
Great video!
Glad you enjoyed it
A melhor explicação! The best explanation!
Thanks !!
Can someone explain what a high and low impedance signal is?
It is not a physical correct way o saying, but it helps to understand circuits.
I call a high impedance signal, the one the comes from a high impedance source.
These are signals "weak", represented by high voltages with low current capacity.
Low impedance signals are signals "strong", the comes from low impedance sources.
Excellent!!
Great video Gregory! How does one go about calculating the value to be used for the Emitter resistors when building out a push pull amplifier? You mentioned you used a 3.9 ohm for each transistor, but I'd like to know how you determined that please.
Hello man!
In the example I used 3.9 because it was what I had around.
The resistance needs to be calculated based on the bias voltage and the bias current needed, and it needs to compensate the Vbe temperature coeficient.
Excellent explanation thank you
Thanks!
👋Hello Gregory I am from India you explained very great using oscilloscope this video will help the people who are interesting in designing of complimentary symmetry amplifier. Please upload one video of push pull amplifier using high voltage mosfet like IRF 150, IRF 250 And so on
When you touch the water you create waves. When you tap it with two fingers you get resonance in different forms called amplifier. It all depends on number of holes in the lattice.
At 6'30''' the 0.3V output voltage will be split between the emitter R and the load if current is flowing, which it will be as the Q is on.
great explanation, thanks
Thanks!
Which transistor can be used for 700 KHz switching speed
2n2369?
Great job. Subbed and rang the bell. Thanks!
Welcome to the channel!!
does the push pull pair invert the input signal?
No!
Beautiful explanation, couldn't we also use an opamp with feedback going from output to the inverting terminal and the signal coming into the non inverting terminal of the opamp
It would be interesting to see (both theoretically and in practice) how such a push-pull pair operates given a load that includes reactive components. The reason is that it's the current which matters when deciding which transistor is open, but its phase is not the same as of the voltage.
I wish my teacher at university had explain it like this
Awesome explination thank you! I am just a little confused on how the biasing network works when you use a diode to achieve your biasing. Why does the transistor also recieve a 0.7V when the boasing diode has the same. Will you please be able to explain this in a beginner way showing the cutrent flow of this system. Thank you!!
The diode is in parallel with the base !!
Hello sir u r perfect teacher
Thank you man!! Please show the channel to your friends to help me grow it!! 😀
So, theoretically it would be best (most thermally stable) to mount the biasing transistors on the same heatsink as the output transistors.
Yep!!
This video is just fantastic! Had to watch it a few times to absorb all of it (and probably still missing some insights).
I have one question. At @30:16, what are those little current spikes (red trace) when the signal enters in cross-over? They seem to remain there also when we move to AB class.
Thank you!!
Good question! It seems more like current spikes from the junctions capacitance, responding for the transients between the positive and negative cycle.
Would be nice to investigate it more!
This is the best explanation I found. Thanks.
I have two questions:
1) has the capacitors to be polarity dependent(electrolytic)? In such case, how we can connect the capacitor in series to the load?(is the positive pole on the load or between the two Re?)
2) are the two identical resistors in series with Vbe multiplier used to maintain reverse polarity of collector base of BJTs so that they are in active region? If so, how can we choose their values?
1) for lower frequencies, probably you will use high value electrolytic capacitors. In this situation, you connect the positive side to the transistor bridge.
2) You can calculate as a voltage divider. The bottom resistor will always have constant 0,65V, so you calculate the upper one to get the desired output voltage.
@@AllElectronicsChannel I tried the circuit. Re must be greater (10 Ohms) and transistors heats up too much after some time. With Re=3,9Ohms the transistors was damaged. I will try with bigger transistors
good work !
Thanks!!
What is the "chewing" of active device? Can't get it.
How do I know the amplifier is class A, B, AB
so interesting video. can u please teach me how to design amplifier push pull with 80W minima outgoing
Excellent..!!
well done!
Thanks!
Hi Gregory ... Thank you very much for going by English language in this channel and your explanation on Class A , B , AB was very clear to understand the topology of these classes... But I would to ask if you can rename your channel to have " ( ENGLISH ) " word so it will be much easier for viewers to know than your original Portuguese one , you may add a link to your original channel in the DESCRIPTION for Portuguese speakers if they may be here !.... Also, Can you please correct your LOCATION country in the ABOUT page to be BRAZIL than USA ?
Hello! I`m retiring from the brazillian TH-cam as I had some legal problems and will focus only on English markets. This is now my main channel. Over time my english will improve. Thank you!
Hi again ... Even with your planning to retire your Portuguese channel , you still have to rename your new channel with good name like to mark it as " ( ENGLISH ) " and specify the location as from BRAZIL as I could not find any other electronic material channel from Brazil at all except yours and WR Kits since 3-4 years of surfing all over the world of TH-cam ... Also , I forgot to say , please put all your communication contact links in the ABOUT page with the most priority of Website URL and Email address... Great thanks for improving your channel content....
One u have to consider about emitter resistors is u dont want to have voltage drop more than the reverse bias emitter base voltage
True!
Please Make a video on "How we can improve the linearity of class c RF amplifier ? "
Excellent explanation Gregory! Thank you for sharing. Can you demonstrate the diode solution as a method of compensation instead of using a transistor?
Hello, thank you!
I don't have any video about it now.
Basically using a diode to generate the DC offset will automatically compensate for the junction voltage to temperature relationship.
You need to put the diode VERY close to the transistor (in the same heatsink and side by side) so any increase in temperature of the transistor will be coupled to the diode.
Each class of amplifier depend on bias voltage upon base on the same of amplifier circuit.
Do you know how to explain op ampe 741 in internal circuit transistors working by using wave forms like you explain this..more students are waiting..please if u can
Nice one!! I will try to make a video about it
Nice Video.Could you make a video about noname toroid core's calculations values. I mean .Calculation of Al value to permability to other values and measuring effective working frequency and loses .Could you make this kind video?
Thanks! I can try, core calculations always seems difficult for me also hahaha
Now I understand this Amp from its root
Excellent method of explanation.
Many thanks!
Thank u sir
are you Brazillian?
What?
@@AllElectronicsChannel you sounds like a brazillian
Xselent teacher
Why do you use 1Mhz signal? not 1Khz? Cheer
We like to play with higher frequencies !
Look like store of instruments😯
Hahahahha
Transmitter am sw 2km +
th-cam.com/video/B5F0R1agTx0/w-d-xo.html
I got mind-fucked! Only now I know what the heck 'distortion' and 'crossover' are in this context. I read and heard a lot about them but I do not think there is anyone else explaining them.
Few of them even mention use small resistor as the bigger resistor is the more noise will be amplified. To a noob like me, it sounds magical not knowing how come resistor has noise. I am sure those 'tutorials' are meant for noobs, otherwise they will not be bothered with the babyish explanation.
Thank you man!
@@AllElectronicsChannel The pleasure is mine!
By the way, Gregory, have you any video on how to choose the 'right' values of resistor? I was understood to always choose the smallest resistor to prevent internal noise (I guess it is inherent stray capacitance and inductance. Same story with capacitor, choose the smallest capacitance possible). But again, only one person (The AudioPhool. TH-camr) I found explaining how to calculate the values, sadly he goes too fast and only transistor that he uses as the example.
I mean, I would like to know how to choose resistors for an operational amplifier as well because nowadays one small chip can do a lot more, saves much more space, and prevents so much more trouble than messing with discrete devices. About noise, integrated circuits these days have extremely low noise due to everything is in close proximity and internal resistors are microscopic.
Your accent is so cute.
😄😄😄
damn bro save some silly scopes for the rest of us
Ic4580
crackk