That's actually the first really helpful video about differential amplifiers. No math needed at first, but a fundamental understanding of what it does. Great job...
The beauty of a Differential Amp is that it only amplifies the signal Difference between the two inputs i.e. anything else, signal (noise) between an input rail and B+ or B- (or ground on a single supply typology) will not be amplified, thus a useful low-noise tool is born. When we modify the circuit by sharing a common emitter resistor (and capacitor, in some cases), the "Long Tailed Pair" that is commonly used for Phase Inversion in a Class AB Amp is created. This structure is used for the input of every Op Amp. You can also see this method applied to many Push-Pull Audio Tube Amps ( look at the schematic for Fender Twin Reverb, as an example). Prior to this, it was common to use just a single tube or transistor for Phase Inversion; the signal would be applied to the base of a transistor or the grid of a tube, equal resistor values would be applied for the Plate and Cathode of a tube (say 56k), or the Collector and the Emitter of a Transistor (say 10k), thus making a somewhat balanced output signal for the positive and negative rail outputs. The problem with this typology, is that the positive signal is referenced to the B+ and the negative signal is referenced to the B- (or ground), so noise from those two sources creep their way into the signal chain; not so with the Differential Amp. Also worth noting... the Long Tailed Pair makes a much more pleasing music distortion, whereas the Cathode Style Phase Inverter does not. You have to also remember that tubes came before transistors, and the basic gain typologies have remained the same.
Excellent tutorial Rick! Clear and well explained as usual. As long as you focus so well on basics principles, basement knowledge becomes strong enough to support more on top! Thank you very much for your dedication preparing this learning material. Best Regards. Pablo
I wish I could put thousands of likes you touched a very powerful subject and the way you explained it it truely elevated my understanding and you deserve a big thank you.
Very nice explanation of how a differential amplifier works with very practical examples and experimental way of explaining how and what you can do out of it.thanks for the very tutorial lesson; I have learnt quite a lot.
Thanks DigiSDR The load resistors are always in the circuit when the signals are the same or different. And so are the emitter resistors, but their for biasing the bases. The most signal will be across the load resistors.
I like the way you explain this movie! Every single word I understood despite the fact that I know pronunciation of English words not very well. And this example with the music and the speech at the end - is just geniously! Thank you!
Thanks twirmd I don't know of any reason why MOSFETs could not be used in a differential amplifier. I bought some more MOSFETs for experimenting with making a flip-flop circuit, hopefully easier to build. I'll try a differential amplifier to, sounds like a good idea.
@AndyDaviesByTheSea Hey Andy, I don't remember if I have or not, it was an exercise and lesson in one of my Heath Kit courses. And yes with analog recordings this process is difficult. Today I would used digital recordings. Using my digital sound applications, I have sync-ed two sound sources, recorded by two different digital devices, of the same thing for over 10 minutes and they remained in perfect sync. I was amazed because I remember how difficult it was, now it is nothing. Regards Rick
Thanks jenko701 Sounds like it will work. Anything that is the same at both outputs is a null between the outputs. It should be greatly reduced or removed. This video is a simple example, there are chips that can do a much better job. I would Google the information.
@Serpico261 Yes. The output is not high. I ran the output from the transformer to an amplifier. At this point the output is low because it is the difference between the two transistor outputs. It is useful and it is easy to amplify. And the video is not fudged. what you see is what happened. The transistors are 2N2222.
@AndyDaviesByTheSea Hey Andy, I don't know how many Heath Kit courses I have done, well over fourteen. About the last one was building an helium neon laser in the Laser course. About the last lesson in this course was using the laser to make a sound interferometer. I could hear myself walking and cars passing by the house. I made a video on the interferometer using a laser pointer. In another video using the laser pointer I audio modulated it and the sound quality is very good. Regards, Rick
@CassetteMaster Sounds like it will work. Anything that is the same at both outputs is a null between the outputs. It should be greatly reduced or removed. This video is a simple example, there are chips that can do a much better job. I would Google the information.
Dear AllAmericanFive Radio I really appreciate your effort in putting this video with explanation. If you dont mind can you please provide the transistor type(model) used so that I can understand why those specific resistor and cap values used.
Thank you for the video. I would like to understand how this circuit works. How the volts are placed on the elements. Is it possible to show how it works ?
Transistor, How Does it Work in a Circuit, Demo ruclips.net/video/vs3zUHdlsYY/видео.html Transistor What does it do in a circuit Visual Demo ruclips.net/video/o1ygTZTHDnE/видео.html Transistor Amplifier for the Beginner, the basics ruclips.net/video/l-rfPfRgNJ8/видео.html Biasing an Audio Transistor ruclips.net/video/KtXE7s5DlcI/видео.html
@hmerrett If you have just the sound you want to remove recorded, it is possible to remove it, one channel at a time. I think there are sound applications that can do this all in the computer today.
It is very interesting... i want to make like this... can i know how or what kind of signal did you put in..and how? Is it alright? Ad please teach me how to put an audio transformer?
@AllAmericanFiveRadio Hi Rick, Yes, I guess if you can keep count of things it’s got to make it easier, never thought of that. You say ‘... in one of my Heath Kit courses...’ I don’t know that they did course but I imagine that they must have been hugely informative; I’ll have to look into that a bit more it sounds very interesting. Ps did you see my ‘Soldering tip’ video? Kind Regards ... Andy
If you had two radio stations and if one of the stations bled over on to the other, in thery you could remove that station with a diff amp buy taking a clean copy of one of the stations signal and the copy that had both, run them through a diff amp and you could get rid of the unwanted audio and just get the audio you wanted. what do you think.
How interesting. People said that there was a mistake in the movie Atomic Blonde, that when Loraine Broughton recorded David Percival and Aleksander Bremovych separately, and pieced the recordings together to play for MI6 that the recording would have had different background sounds because of parts of the conversations being recorded in bars and clubs playing music and having lots of background noises. However, if she wore a wire recording the conversations, music, and background noises, and had a wire in her coat recording just the music and background noises, that got hung up out of earshot each time she went to the venues, she could have taken the music and background noises recording and passed it through a differential amplifier with the recording of the conversations etc, and removed the music and background noises leaving just the conversations. So technically it wasn't a mistake because her spliced recording had no background sounds, just the conversations, and Eric Gray and Chief C were so intrigued with her story, and thinking Percival was Satchel, that it didn't occur to them that it was strange that the recording had no background sounds. Cool.
Oh yes this is a very useful circuit. I'm sure that there are now digital differential circuits that are even more amazing. I think I'll make a laser interferometer and bounce the laser off a window to hear the audio in that room.
Hi Rick, nice clean demo. Have you ever stripped a sound off a recording like that? I can see the possibility but I could imagine that you’d get some heterodyning unless you could maintain perfect in phase sync. Kind Regards ... Andy
Yes, if you where to have two inputs 180 degrees out of phase this circuit would add them together. To the limits of the circuit of course. If you over drive it you'll get distortion.
@dmottern1952 Thanks Doug, They are very interesting and useful too. Hope your class finds op and diff amps interesting. From the response I'm getting, a few RUclipsrs find them interesting also. Rick
I would expect the signal cancelling if the outputs had inverse phase (out 2 180 deg from out 1, for instance) Since here the circuit is the same at both sides, I guess there is no phase inversion, so, why they cancel eachother? I would expect both signals summing, not cancelling
Electrons flow from negative to positive in a circuit. If the red LED is lit that means electrons are moving from 1 up through the 1K resistor, but also through the red LED and up through the other on 1K resistor. If the green LED is lit that means electrons are moving from 2 up through the 1K resistor but also through green LED up through the other 1K resistor. If both the red and green LEDs are not lit, that means both inputs are the same.
Hi, a 1982 mosfet amplifier has a differential input stage ( pair of PNP's) and a current mirror on top ( a single PNP transistor with 24V Zener in parallel) . The two differential PNP's has their collectors connected to the base of two NPN drivers, where the first NPN driver has it's collector connected to the base on the upper PNP driver. ( 4 mosfet as output stage).....You see, the mosfet schematic had an error that showed the differential input transistors as NPN's (they should have been PNP's)......Could you show when to use PNP's and NPN's......and ...why not not use NPN's as input transistors? thanks for all your fine and useful videos...best regards Kim
Out of curiosity, why are BJTs more commonly used in differential amplifiers instead of MOSFETs? At least I'm assuming they do, because I can find plenty of resources that cover only amplifiers with BJTs but hardly anything is out there on MOSFET differential amplifiers.
FETs and BJTs are two very different things FETs are more like switches and BJTs amplify the current. To learn more you will have to ask someone much smarter than I.
Okay, so if you get a chance to respond to this comment, tell me something: I've been studying how tube amps work, lately, and am now curious about solid state amps. Say you were to put a phase inverter somewhere in the signal path on one side of that differential amp, and hook the outputs up to an audio output transformer, as you did, then short the inputs together in order to feed them the same input signal. Would that give you a double-ended, "push-pull" amplifier that would essentially double the amplitude of the output, rather than having the two output signals cancel eachother out? This is how it works in tube amps that have two output tubes, but I don't know if the same technique is used in solid state amps.
Transistor Amplifier for the Beginner, the basics ruclips.net/video/l-rfPfRgNJ8/видео.html Transistor Push Pull Amplifier, for the Beginner, no transformer, the basics ruclips.net/video/e_SE4KQjYR8/видео.html Transistor Push Pull Audio Output Amplifier ruclips.net/video/NU8Yk0bXlkk/видео.html Audio Phasing, Important and Useful ruclips.net/video/lgWLCG5vg5c/видео.html
Thanks for the reply, but...hmm...maybe I don't have my terminology straight, here. By my understanding of a push-pull, or double-ended amp, rather than the cascading mentioned in that video, the two transistors (or tubes) output to opposite ends of the primary winding of an output transformer, with one output being 180 degrees out of phase of the other. So when one end of the winding is getting a + impulse, the other end is getting an equal - impulse, and vise-versa, effectively doubling the amplification. Does push-pull mean something different in the solid-state world than it does in the vacuum tube world?
I can't find my reply, Google is doing such a great job. If you put in an inverter on one side it would act more like a Push-Pull but not optimum. Search my channel. This is a more efficient Push-Pull. Transistor Push Pull Amplifier, for the Beginner, no transformer, the basics ruclips.net/video/e_SE4KQjYR8/видео.html
That's actually the first really helpful video about differential amplifiers. No math needed at first, but a fundamental understanding of what it does. Great job...
Thank you.
The best explanation! Never though about differential amplifier as two A class amps together. My life is complete now. Thank you!
Amazing video! One of the clearest I've seen, thusfar.
Thank you, and your welcome.
Thank you for the very instructive video. Besides the valuable content the professionalism in the way it is explained deserves an A+
Thank you, and your welcome.
Many thanks for the video. it helped me understanding the differential amplifier so much. Many many thanks
Thanks and your welcome.
The beauty of a Differential Amp is that it only amplifies the signal Difference between the two inputs i.e. anything else, signal (noise) between an input rail and B+ or B- (or ground on a single supply typology) will not be amplified, thus a useful low-noise tool is born. When we modify the circuit by sharing a common emitter resistor (and capacitor, in some cases), the "Long Tailed Pair" that is commonly used for Phase Inversion in a Class AB Amp is created. This structure is used for the input of every Op Amp. You can also see this method applied to many Push-Pull Audio Tube Amps ( look at the schematic for Fender Twin Reverb, as an example). Prior to this, it was common to use just a single tube or transistor for Phase Inversion; the signal would be applied to the base of a transistor or the grid of a tube, equal resistor values would be applied for the Plate and Cathode of a tube (say 56k), or the Collector and the Emitter of a Transistor (say 10k), thus making a somewhat balanced output signal for the positive and negative rail outputs. The problem with this typology, is that the positive signal is referenced to the B+ and the negative signal is referenced to the B- (or ground), so noise from those two sources creep their way into the signal chain; not so with the Differential Amp. Also worth noting... the Long Tailed Pair makes a much more pleasing music distortion, whereas the Cathode Style Phase Inverter does not. You have to also remember that tubes came before transistors, and the basic gain typologies have remained the same.
Thanks.
Excellent tutorial Rick! Clear and well explained as usual.
As long as you focus so well on basics principles, basement knowledge becomes strong enough to support more on top!
Thank you very much for your dedication preparing this learning material.
Best Regards. Pablo
One of the best explanation. Thank you.
I'm starting to learn and understand more about amplifiers every day in your Channel. thank you so much.
Thanks and your welcome.
Glad the videos help.
I wish I could put thousands of likes you touched a very powerful subject and the way you explained it it truely elevated my understanding and you deserve a big thank you.
Very nice explanation of how a differential amplifier works with very practical examples and experimental way of explaining how and what you can do out of it.thanks for the very tutorial lesson; I have learnt quite a lot.
Thank you, and your welcome.
alot better than my teacher ever explained it to me. Very informative and clear! thanks!
Thanks
Thanks DigiSDR
The load resistors are always in the circuit when the signals are the same or different. And so are the emitter resistors, but their for biasing the bases. The most signal will be across the load resistors.
I like the way you explain this movie! Every single word I understood despite the fact that I know pronunciation of English words not very well. And this example with the music and the speech at the end - is just geniously! Thank you!
You always present great videos on RUclips. I look foward to your videos.
Thanks
Rick - outstanding video. Just finished the chapter on op amps with my students, where we talked about diff amps. Doug'
Very good job, Rick. Clear as glass. If I can understand it, anybody can.
Regards,
John
Men may come and men may go, but your legacy will life forever. Thank you.
Thank you and your welcome.
Nice video, keep it up, thanks for sharing it:)
Thank you.
Thanks twirmd
I don't know of any reason why MOSFETs could not be used in a differential amplifier. I bought some more MOSFETs for experimenting with making a flip-flop circuit, hopefully easier to build. I'll try a differential amplifier to, sounds like a good idea.
You explained it better than my lecturer! Thank you very much for the video! =)
@THEtechknight
You can control the sound quality with the second input.
great explanation, greetings from Venezuela! :)
Absolutely brilliantly explained and I was suffering to understand other videos here thank you sir
Thank you. hope this video helps.
@AndyDaviesByTheSea
Hey Andy,
I don't remember if I have or not, it was an exercise and lesson in one of my Heath Kit courses. And yes with analog recordings this process is difficult. Today I would used digital recordings. Using my digital sound applications, I have sync-ed two sound sources, recorded by two different digital devices, of the same thing for over 10 minutes and they remained in perfect sync. I was amazed because I remember how difficult it was, now it is nothing.
Regards
Rick
This was very Educational I enjoyed it . Thanks////// I look forward to your videos. Thanks again.
thanks alot for this video! great explanation like Vadim Harenco says.. I also never thought about two class A amps together!
Thanks
Great explanation, thanks for posting!
Excellent demonstration.
Thank you, and your welcome. Hope the video helps.
Thanks jenko701
Sounds like it will work. Anything that is the same at both outputs is a null between the outputs. It should be greatly reduced or removed. This video is a simple example, there are chips that can do a much better job. I would Google the information.
@Serpico261
Yes. The output is not high. I ran the output from the transformer to an amplifier. At this point the output is low because it is the difference between the two transistor outputs. It is useful and it is easy to amplify. And the video is not fudged. what you see is what happened. The transistors are 2N2222.
I absolutely love your teaching style. Thank you so much for this, friend.
Thanks and your welcome.
Can't believe what I just saw. That's quite an amazing experience.
Thanks, and your welcome.
Thanks!
Awesome video.
Very nice video. To follow along and get the same results you MUST have a matched pair of transistors and preferably even matched resistors, etc..
Thank you and your welcome.
@AndyDaviesByTheSea
Hey Andy,
I don't know how many Heath Kit courses I have done, well over fourteen. About the last one was building an helium neon laser in the Laser course. About the last lesson in this course was using the laser to make a sound interferometer. I could hear myself walking and cars passing by the house. I made a video on the interferometer using a laser pointer. In another video using the laser pointer I audio modulated it and the sound quality is very good.
Regards,
Rick
Great video and top explanation, thank you
gud to hv practical application with theory...luv the way u taught👍👌
Thanks
great explanation, much thanks,
@CassetteMaster
Sounds like it will work. Anything that is the same at both outputs is a null between the outputs. It should be greatly reduced or removed. This video is a simple example, there are chips that can do a much better job. I would Google the information.
Clear explanation. Thanks for making this video...
Thank you , that really helped clear things up for me.
Thank you, and your welcome.
Very well explained ! Thank you !
Thanks
This is a good demonstration
Thanks and your welcome.
Dear AllAmericanFive Radio I really appreciate your effort in putting this video with explanation.
If you dont mind can you please provide the transistor type(model) used so that I can understand why those specific resistor and cap values used.
Great as usual.
Please do some video about audio transformers, impedance transformes, etc.
THANKS.
Well that clears up a lot of confusion, thanks!
Thanks
Very useful video about differential amplifiers. Thanks
Thank you, and your welcome.
Nice and good information!
Thanks
AllAmericanFiveRadio You're wellcome. It's nice, that people do those videos. I have learn a lot just looking those videos and it is fun.
Wow amazing explanation. Thank you so much sir.
+Mohammed Said Thanks
super !! tks a lot for this perfect explaination
Thank you! And your welcome!
Thank you for the video.
I would like to understand how this circuit works. How the volts are placed on the elements. Is it possible to show how it works ?
Transistor, How Does it Work in a Circuit, Demo
ruclips.net/video/vs3zUHdlsYY/видео.html
Transistor What does it do in a circuit Visual Demo
ruclips.net/video/o1ygTZTHDnE/видео.html
Transistor Amplifier for the Beginner, the basics
ruclips.net/video/l-rfPfRgNJ8/видео.html
Biasing an Audio Transistor
ruclips.net/video/KtXE7s5DlcI/видео.html
Good video,great that you demonstrate it....:D
amazing explanation and demonstration. thank you
Thank you, and your welcome.
very good example,thank you
Thanks
Super video as always Rick
Excellent explanation. Thank you very much.
Thank you.
@hmerrett
If you have just the sound you want to remove recorded, it is possible to remove it, one channel at a time. I think there are sound applications that can do this all in the computer today.
VERY CLEAR! THANK YOU!
Thanks
HELL YEAH! Now am gonna change majors. haha
Best explanation
THANK YOU!
i hadnt seen this one,very well done.
Wow! That was very interesting , thank you.
Thanks and your welcome.
Thanks CassetteMaster
That would be interesting to try, to remove white noise. It is in the background. That just might work.
Great tutorial!
this is amazing!!!
Thank you, and your welcome.
@palotitoe
Thanks Pablo,
The basics are super important. Everything depends on that knowledge.
Regards
Rick
It is very interesting... i want to make like this... can i know how or what kind of signal did you put in..and how? Is it alright? Ad please teach me how to put an audio transformer?
@AllAmericanFiveRadio Hi Rick, Yes, I guess if you can keep count of things it’s got to make it easier, never thought of that.
You say ‘... in one of my Heath Kit courses...’ I don’t know that they did course but I imagine that they must have been hugely informative; I’ll have to look into that a bit more it sounds very interesting. Ps did you see my ‘Soldering tip’ video?
Kind Regards ... Andy
If you had two radio stations and if one of the stations bled over on to the other, in thery you could remove that station with a diff amp buy taking a clean copy of one of the stations signal and the copy that had both, run them through a diff amp and you could get rid of the unwanted audio and just get the audio you wanted. what do you think.
How interesting. People said that there was a mistake in the movie Atomic Blonde, that when Loraine Broughton recorded David Percival and Aleksander Bremovych separately, and pieced the recordings together to play for MI6 that the recording would have had different background sounds because of parts of the conversations being recorded in bars and clubs playing music and having lots of background noises. However, if she wore a wire recording the conversations, music, and background noises, and had a wire in her coat recording just the music and background noises, that got hung up out of earshot each time she went to the venues, she could have taken the music and background noises recording and passed it through a differential amplifier with the recording of the conversations etc, and removed the music and background noises leaving just the conversations. So technically it wasn't a mistake because her spliced recording had no background sounds, just the conversations, and Eric Gray and Chief C were so intrigued with her story, and thinking Percival was Satchel, that it didn't occur to them that it was strange that the recording had no background sounds. Cool.
Oh yes this is a very useful circuit. I'm sure that there are now digital differential circuits that are even more amazing. I think I'll make a laser interferometer and bounce the laser off a window to hear the audio in that room.
The transistor type is NPN. The transistor are two 2N2222.
thanks helped a lot !!!
I wonder if this could cancel out DC bias's background noise while playing back.
Excellent! thanks
Very good thx!
Great video thanks
Hi Rick, nice clean demo. Have you ever stripped a sound off a recording like that? I can see the possibility but I could imagine that you’d get some heterodyning unless you could maintain perfect in phase sync.
Kind Regards ... Andy
does this cancellation have to do with the phase of the 2 identical signals or am i overseeing sth very simple here..?
Yes, if you where to have two inputs 180 degrees out of phase this circuit would add them together. To the limits of the circuit of course. If you over drive it you'll get distortion.
VERY INSIGHTFUL
Thanks
I am so appreciated
+Weimin Leee Thanks
@dmottern1952
Thanks Doug,
They are very interesting and useful too. Hope your class finds op and diff amps interesting. From the response I'm getting, a few RUclipsrs find them interesting also.
Rick
Men like you are hard to find!
Thank you. Tell your friends!
I would expect the signal cancelling if the outputs had inverse phase (out 2 180 deg from out 1, for instance) Since here the circuit is the same at both sides, I guess there is no phase inversion, so, why they cancel eachother? I would expect both signals summing, not cancelling
If both signals are in phase at the output, there is no electron flow, no output.
When you hear voice like this one you know you learn something :D
Thank you, and your welcome.
Fabulous!
I have a question, why does the red led turns on with imput 1 and nor the green one, sorry if it is a dumb question
Electrons flow from negative to positive in a circuit. If the red LED is lit that means electrons are moving from 1 up through the 1K resistor, but also through the red LED and up through the other on 1K resistor. If the green LED is lit that means electrons are moving from 2 up through the 1K resistor but also through green LED up through the other 1K resistor. If both the red and green LEDs are not lit, that means both inputs are the same.
Killer explanation.
Thank you, and your welcome.
Thanks falcon02012
Yes, it seems like magic too.
Thank you.
THANK YOU!
Can this drive use to give the same sine wave to mosfet power inverter
You can use the output to drive MOSFETs if you want.
best explanation sir.
Thanks
Hi, a 1982 mosfet amplifier has a differential input stage ( pair of PNP's) and a current mirror on top ( a single PNP transistor with 24V Zener in parallel) . The two differential PNP's has their collectors connected to the base of two NPN drivers, where the first NPN driver has it's collector connected to the base on the upper PNP driver. ( 4 mosfet as output stage).....You see, the mosfet schematic had an error that showed the differential input transistors as NPN's (they should have been PNP's)......Could you show when to use PNP's and NPN's......and ...why not not use NPN's as input transistors? thanks for all your fine and useful videos...best regards Kim
Thank you Kim. I have copied your comment for a future video idea.
@@AllAmericanFiveRadio Thank you :-)) I was hoping you would say that...best rgds Kim
very good tutorial
Thanks
thank you!
super sir very nice explanation
Nice
Thank you, and your welcome.
Thanks!
Out of curiosity, why are BJTs more commonly used in differential amplifiers instead of MOSFETs? At least I'm assuming they do, because I can find plenty of resources that cover only amplifiers with BJTs but hardly anything is out there on MOSFET differential amplifiers.
FETs and BJTs are two very different things FETs are more like switches and BJTs amplify the current. To learn more you will have to ask someone much smarter than I.
Okay, so if you get a chance to respond to this comment, tell me something: I've been studying how tube amps work, lately, and am now curious about solid state amps. Say you were to put a phase inverter somewhere in the signal path on one side of that differential amp, and hook the outputs up to an audio output transformer, as you did, then short the inputs together in order to feed them the same input signal. Would that give you a double-ended, "push-pull" amplifier that would essentially double the amplitude of the output, rather than having the two output signals cancel eachother out? This is how it works in tube amps that have two output tubes, but I don't know if the same technique is used in solid state amps.
Transistor Amplifier for the Beginner, the basics
ruclips.net/video/l-rfPfRgNJ8/видео.html
Transistor Push Pull Amplifier, for the Beginner, no transformer, the basics
ruclips.net/video/e_SE4KQjYR8/видео.html
Transistor Push Pull Audio Output Amplifier
ruclips.net/video/NU8Yk0bXlkk/видео.html
Audio Phasing, Important and Useful
ruclips.net/video/lgWLCG5vg5c/видео.html
Thanks for the reply, but...hmm...maybe I don't have my terminology straight, here. By my understanding of a push-pull, or double-ended amp, rather than the cascading mentioned in that video, the two transistors (or tubes) output to opposite ends of the primary winding of an output transformer, with one output being 180 degrees out of phase of the other. So when one end of the winding is getting a + impulse, the other end is getting an equal - impulse, and vise-versa, effectively doubling the amplification. Does push-pull mean something different in the solid-state world than it does in the vacuum tube world?
I can't find my reply, Google is doing such a great job. If you put in an inverter on one side it would act more like a Push-Pull but not optimum. Search my channel. This is a more efficient Push-Pull.
Transistor Push Pull Amplifier, for the Beginner, no transformer, the basics
ruclips.net/video/e_SE4KQjYR8/видео.html