#198 

I wish I could wind my age back by 50 years, and still have your videos. Learning would have been so much easier. Unfortunately, I was taught by people that felt the need to show how clever they were at maths, leaving me lost. But, you do awesome demonstrations, with brilliant explanations. Thank you.

In the world dominated by Java, ARM, ... your videos "back to the basics" are awesome! They are like shake off the dust from my analog soul. I love them and keep on going!

At 66 years old, I find it fascinating trying your circuits, I wish I'd kept with it when I was young, thank you.

Cool! I had never heard of this type of circuit. Thanks.

I love the way you explain! I've seen various videos on the subject and also about class AB amplifiers, but no one seems to think of playing a pure sine wave so that people can actually hear(12:20) how the distortion disappears with the bias change, and not just look at graphs.

Thanks again for great educational clip. I have seen this circuit on the push-pull Amps, but never understood it well. Now, I understand them well. I guess by extension we could do Vth Multipliers in MOSFETs. Thanks again for great Educational Clip.

Thanks. I actually watched this video quite a while back, but I couldn't follow it at all. Now it makes complete sense. Although I understand Calculus well, which is not the same as doing derivatives and integrals, which really doesn't matter as much as understanding what it means. I have trouble following the math. I really guess that's a little bit of boredom, but I'll pull that in after a little bit. It's important to do at some point. I'm 53 now and thrilled to be getting back into electronics again. I did it very very young age and without hardly any money. Now I can actually buy some decent equipment. I'm starting to be able to use it, too. I'd enjoy using some good textbooks, but only with a group of people. Technical learning is a bit boring as DIY. Practical applied learning is fun now. Finally. Thanks again!

Brilliant! Thank you. I know this video goes back a bit, but it is sincerely appreciated, a super clear explanation. I am researching Vbe mulipliers as I want to come up with an alternative to the multi-diode bias spreaders used in vintage hifi. The breadboard will be coming out very soon!

I have studied about this in amplifier design during my college days and seen in many transistor power amps… but after 29 years I am seeing working of this circuit in a scope. Awesome to see this ….. Thanks man… you rock.

I work with these "Push Pull" everyday service electron microscopes. All the scan circuits utilize a push-pull circuit. I remember learning about the PUSH-PULL circuit in college, but never fully understood how to compensate for the crossover distortion until NOW! Your videos/ instruction is "Priceless" and should be required viewing for any electrical engineer student!

Thank you. I have a clear headed understanding of it thanks so much. People like you change the lives of people like me. People like you empower and give confidence to people like me. Just thought you should know that.

I love how you go really deep into components analysis and let me discover some new feature every time. These are the best videos about electronics that can be found on youtube. And I always wish I was as smart as you are!

You put out a lot of really great videos that I am finally getting to go through. Thanks for all the great content!

Totally love your videos. They should be shown at universities. You logically develop the ideas and everything makes sense. P.S.: Watching this video again and seeing that I've already commented, so I will edit this one. You need to publish a book where you can fold the pages as you do in your notes. It was fun as a kid and would still be :)

Thank you for taking your time to publish these and showing off that BEAUTIFUL Tek MDO 3104.

Good demonstration. I understand the use of Vbe multiplies in amplifiers better

Great video! I hadn't seen this use of a transistor before. It looks very handy.

Where is the button for 100 thumbs ups? Like Mick Healey below, you have in 13 minutes explained something that I totally missed when I was getting my EE degree. Then again, the $36,000 oscilloscope is helpful! :)

You obviously put a significant amount of preparation into your videos and your command of the subject is obvious. The result is a professional and easy to understand lesson. . Much appreciated!

Very nice demo, thanks for making it. I always enjoy your tutorials, both the drawn circuits and then the demo on test equipment. Very real stuff. Thanks.

Thanks Alan, Excellent Video! You are a Superior teacher with impressive examples.

excellent video, Alan! cristal clear explanation, the use of the oscilloscope clarify and complement a lot the theoretical discussion. I have to say I am impressed by the clealiness of your written material. It should be published as a book a it is! congrats!

Very good lecture as always :) You can also use your beautiful oscilloscope (FFT function) to show how harmonic content changes with regulation and how it is connected with FFT function in our ears. Best Regards

Absolutely magnificient video and demo!

Thanks for a great video with the actual theory behind it.

Amazing video dude!!!! My first comment on RU-vid. Just can't help. SO CLEAR, better than my analog circuit professor lol :)

That was great! Push-pull amplifiers biased with two standard diodes really cant compare to this method when using discrete components, but that's always the standard text book example of how to reduce cross-over distortion and never works well in practice I've found.

Before watching this video, I was aware of Vbe multiplier circuits -- thanks to a coworker. However, I was NOT aware of the push-pull output application! That is brilliant!

This the best explanation about the VBE multiplayer ....... Thank you ..

The best 13:23 I`ve spent so far this year:)

+Nicolay pelov. The bulk of the current flows C-E. The B-E junction is only carrying base current, which is the collector current/beta.

Thumbs up. You obviously put a lot of care into your videos which are very helpful. Thanks, David Lee...

Cool. Very interesting. Thanks for explaining it so well.

Awesome, I just made the connection with this and a amplifier circuit I'm ( Trying ) studying !.....cheers.

Hola Alan! I finally subscribed to your channel. This last of yours, short and to the point, as usual. It allowed me to understand how it the multiplier works and what it is good for. You rank top in my list. Gracias.

I'm subscribed to many RU-vid channels but your is the one I like the most. Your explanations are straight to the point, very easy to follow as well as instructive. Keep the amazing work.

Thanks for yet another great video, Sir. Been following you for a while on here and always look forward to new content from you!

Very useful and very awesome indeed! The explanation and presentation are very clear and nicely interpretable, I like it! Awesome other videos on your channel aswell! You've earned yourself a new sub, keep up the work good man!

In my amplifier output stages I use to couple the transistor of the Vbe multiplier thermally with the output stage and I use a constant current source (f.i. E-103) instead of Rc. In this way you can get a very stable bias current through the output stage.

Great video! You didn't mention of a key point, I think... At least as far as the Class B/AB amplifier goes. If the Vbe multiplier is thermally coupled to the output transistors, then as they heat up and their Vbe drops, so does the that of Vbe of the Vbe multiplier transistor and the bias current through the output stage (and hence distortion) remains more or less constant through the operating temperature range. Also, it can help prevent thermal runaway...

Very clear, well illustrated and concise explanation. Top. Thank you.

Great vids been watching a lot since I found you! Love the 465B and the 485. Learning a lot from your stuff thank for putting in the time!

You're putting a lot of work and time to teach people interested in electronics Thank You.

Thanks for all of your videos! I am currently expanding my electronics knowledge by troubleshooting a Fender M80 bass amp, which has distortion at the output, and this sheds some light, hopefully.

Thank you for making EE videos to educate students and professionals And thank you for not doing old TV tear downs or how to use heat sink compound videos like the guy below the equator is doing.

Thanks a lot for sharing this, I enjoyed it. Another nice property of this circuit is its "build in" temperature compensation of the output stage bias current.

Really enjoyed this. Such a simple yet power circuit to have a adjustable voltage drop.

I never heard of this type of circuitry. Thanks for introducing and explaining it!

this is beautiful demonstration

Thanks again this is another super clear explanation of a useful circuit to have in the analog arsenal.

Perfect class! ..In French slang we say "La classe'"

Wow... I just read up on this and your video really helped piece everything together; Thank you!

Nice explanation, thanks. I've built a number of audio power amps over the years and they always used this circuit to set the O/P stage bias.

Thanks Alan - You explained that very well and I learned something new. Cheers!!

Just what I was looking for. Thank you very much.

Thank you very much, this is just what i needed!!!!

Thanks a lot, i realy love your videos, they are the best. You are realy good at explaning things so that i understand them. Greatings from Denmark

This is great - very clearly explained. Thanks.

Awesome video really helped clear alot of things up. I built the curve trace (octopus circuit) and followed along on my oscilloscope. works perfectly. really helpful.

I sure did hear the raspyness come and go! Very interesting...Thank You!

You continue to produce excellent videos. Good effort. Thank you.

Great explanation, thank you! Just what I was looking for. :)

Great video as always, i"ve learned this back as superdiode circuit .

Excellent video, attracting excellent crowd!

Very good and helpful explanation! Great stuff.

This is really awsome :). please makeup more of these videos with schematics and walkthrough like this. respekt for your work. Best on the Web. thanks

Excellent explanation. thank you!

Loved this, Alan! Thanks!

Info is great! App is golden! Thank You. Bill

Thank you for another excellecnt video and interesting subject.

Another great tutorial, thanks!

Nicely explained ... We are about with few students, every one understood clearly....

This was amazing. Love it.

Wow, nice educational material. Thanks Sir!

Great tutorial! It's probably an obvious point and not sure if it was mentioned, but the transistor shunts away enough current in order to maintain the Vx voltage drop. It will even maintain that drop when the supply voltage varies. That was another key, for me at least, in understanding how the Vbe multiplier works. Also, I think there is a required resistor between Vcc and the output otherwise the output will always be at Vcc.

Another fantastic video! Thank you.

Excellent presentation. Thank you so much.

Thanks for the tutorial!

Thank You for Your really informative and enlightening videos. I now have an understanding of Vbe Multipliers and also what cross-over distortion is. I see that another 'aka' for this circuit is a 'Rubber Diode' according to Wikipedia.

Fantastic video!

great video, thank you for sharing the info.

It's a wonderful video again. Thanks a lot.

Very clear as usual...thanks

Another gem! Thanks.

great as always!

Oh well... I was following along with the videos but this one lost me. Too much above my head so I'll come back to it when I learn more of the basics. Thanks for the video!

Ough snap! This was super-useful! Thanks a lot! ;)

I was just wondering how to improve the audio quality of a simple low power push-pull audio amplifier. Thanks for a great tutorial and demo!

another fantastic video

Great content!

10:00 Oh that's sneaky :) Using the Vbe multiplier here is pretty much the perfect application because of it's temperature coefficient.

Great job!!

Very cool, thx 4 sharing!

This will work out handy for a project I'm working on now: converting an 8mm film projector to high-power LED. I'd like to have a control circuit at 5V, and the original bulb was rated 30V at 86W, so I figured I could use the power tap for it. The power tap supplies about 38VRMS, so I expect to get around 40VDC or more at low currents. However, to use, say a 7805, I'd need a maximum input voltage of about 30V. This circuit will be an easy way to drop 20V or so to drive the 7805 for the low-current logic. I'll need to keep an eye on the temperature, though, as Vbe may drop as low as 400mV ... thankfully the current is quite low, but I'll probably use a relatively big transistor nonetheless.

I'm glad to come across your video on Vbe Multiplier. As I'm in the process of building a transistor stereo amp and in that, it uses a VBE Multiplier Power Regulator to regulate the power supply for the amp. I was wondering if there is a more up-to-date design to serve the same purpose or transistor amp should have transistor power regulator, thanks !

Great tutorial - sure wish RU-vid and teachers like you were around when I was learning electronics! I'll admit to skipping around a bit, so I might have missed this, but did you mention that another great thing about this circuit, particularly in the push-pull application, is that as Vbe changes with temperature, the multiplier's output will track the Vbe shift of the output transistors? So if you cancel the crossover distortion at one temp, it will stay cancelled as temp changes?

this looks like a very fundamental building block, that I have not seen before. I suspect it can replace zeners as well for introducing arbitrary voltage drops.

Good sir nice explanation

cool circuit 👍

***** God bless your good work. There is always so much to learn from your videos and they are so easy to follow, that even a beginner like myself can udnerstand.