How Amplifiers Work: Rectifiers and Filter Capacitors

Подписаться 130 тыс.

Просмотров 164 тыс.

50% 1

This video is a continuation of my previously posted Two Sources of Amplifier Hum Video, and explains (in very basic language) the different methods of rectification used in amplifiers and how the filter capacitors function to eliminate the 120 cycle/sec ripple (hum) that remains after the 60 cycle/sec current is rectified. In addition a comparison of commonly used guitar amp rectifier tubes is presented, and different types of diode (solid state) rectification are discussed.
PLEASE NOTE: There is an error in the diagram for Half Wave Rectification. The output should be labelled "120VDC (169VDC RMS)" instead of 60VDC. With half-wave rectification, you get approximately the same voltage out of the single diode that you put in, but only half the current, since the negative portions of the waveform (i.e. half the current) are blocked.
If you enjoy videos featuring classic vintage amplifiers, jukeboxes, and related electronic devices, and you are curious about how they function, then please subscribe to my channel. You will gain immediate access to over 70 more videos, and you will be alerted each time a new video is posted.
Thanks for watching !!

Видеоклипы

Опубликовано:

3 окт 2024

Ссылка:

Скачать:

Готовим ссылку...

Добавить в:

Мой плейлист

Посмотреть позже

Комментарии : 582

@adw141 7 лет назад

I am a physician with absolutely no musical talent, but an endless thirst for knowledge on all fronts, including circuit design. I ended up here after searching for videos on how tube amps work. I've been up for hours watching your videos. Your patient and thorough explanations are incredible. Thank you for your time and effort in contributing these videos to the collective knowledge base that is the internet. The world is a better place because of them!

@UncleDoug 7 лет назад

Wow.....thanks so much for your very kind words, ADW. We sincerely appreciate them, and are glad to hear that the videos are helpful and informative.

@Sleepysidney 7 лет назад

Uncle Doug needs his own t.v. show, he is truly one of the best contributors on RU-vid. No doubt about that.

@UncleDoug 7 лет назад

Thanks, SS, but only if Rusty can be my Ed McMahon :)

@ryanfulldark2775 3 года назад

Oh absolutely! If you’re into vintage amplifiers this is like a technical education. So valuable. I know a younger fella here in New York that owns his own shop repairing and restoring these beautiful creations and cites Uncle Doug as his influence and inspiration. That’s how far this amazing work reaches!

@electronicsafrica 2 года назад

the smartest people explain things in the simplest terms - thanks!

@UncleDoug 2 года назад

Thanks. I hope our explanations are always clear and concise, EA.

@kiwar193 2 года назад

Thank you very much. I've tried so hard other the years to understand amplifiers and nothing stuck in my head. Your explanations just made it click for me somehow, very clear and concise. I feel like a complex subject finally fits inside my small brain 😁 I very much appreciate these videos. Subscribed. 👍

@UncleDoug 2 года назад

Glad to hear it, KW. Thanks for subscribing :)

@jeffharrison1090 Год назад

The absolutely best presentation I have found! The best parts are the LARGE simple drawings and the physical tubes and electronic components that mirrors, emphasis and tie everything together! Great work! Will continue to watch more of your series!!!

@UncleDoug Год назад

Thanks so much, Jeff. We're glad to hear that our videos are easy to understand.

@masonclay1857 3 года назад

I'm prepping for my General-class ham radio license and finally found someone who can explain this in a way that makes sense. THANK YOU UNCLE DOUG!

@UncleDoug 3 года назад

You're welcome, Mason. Good luck on your test.

@cnhueston6802 7 лет назад

High quality teaching Doug. Simple, well thought out lessons. Camera play and editing are straight. I dropped out 30 years ago because I could not visualize what circuits do. This is so plain to me now, thanks Doug for taking the time and effort. Time for me to build an amplifier...

@UncleDoug 7 лет назад

You're welcome, CN. Thanks for your very nice comments. Best of luck with future projects.

@cnhueston6802 7 лет назад

Actually, I have an odd question. I have a reason why for this train of thought other than purely electronic, so bear with me sir. I want an AC power supply at 108V @ 54Hz. Could I achieve that with an AC to AC transformer and/or some sort of oscillator? I have no idea except a circuit I presume changes 110V@60Hz to 230V@50Hz?, or is that a simple switch? Is this even do-able? Thanks for any input.

@UncleDoug 7 лет назад

You don't mention the current capacity of his power supply, CN, but it's an important factor. As far as the 108VAC, this would be easily achieved with good accuracy using a Variac. You can also use an inverter to convert DC into AC of varying frequency by altering the frequency of the oscillator withing the inverter. Here is an excellent source of info: electronics.stackexchange.com/questions/148023/how-to-change-the-frequency-of-ac-supply

@DonStrimbu 8 лет назад

+Uncle Doug, thank you. Best time I've spent on RU-vid lately. I learned more about tube amps from you in 2 hours than I did elsewhere in 10 years.

@UncleDoug 8 лет назад

You're welcome, Don. It's great to hear that the videos are an effective learning tool.

@anotherOneMore7 4 года назад

Agreed. I built a few amps in the early 2000s and due to life interference dropped it a few years later. There were forums to learn from, and I learned a lot back then, but having the visuals makes the learning process so much easier to comprehend. It is inspiring me to pick up some of my old unfinished projects.

@moses1202 3 года назад

I love to hear uncle Doug explain things even some very basic stuff.

@UncleDoug 3 года назад

We're glad you do, Moses. Thanks :)

@edwardhannigan6324 4 года назад

I know I'm popping all over your videos like the popcorn electrons on a cathode, but I was in a complete fog about rectification tubes etc. and their use of and filtering..! I spent the last 13 or so minutes with your video and the 'Fog' has cleared Doug. Fab explanation. Thanks..Ed U.K.

@UncleDoug 4 года назад

That's great news, Ed. Thanks for making our day :)

@microcosm6871 9 лет назад

I'm blown away by the wealth of information you provide on your channel. I'm just getting started learning about tube amplifiers and am very excited to start digging in here. Thank you SO MUCH for sharing, sir.

@UncleDoug 9 лет назад

microcosm You're quite welcome. Rusty and I are glad you're enjoying our videos and sincerely appreciate your very kind words. Thanks for watching :)

@that1personMan 8 лет назад

I love your videos. Simple, to the point, and informative. Perfect for learning new things at home

@UncleDoug 8 лет назад

Thanks so much, 1PM. We're glad you like them :)

@BandGeekRecords Год назад

I’ve been binge watching your videos. You use great analogies to explain the concepts, yet keep enough of technical aspects to have plenty of aha moments. Keep up the great work!

@UncleDoug Год назад

Thanks, BGR. Glad you enjoy our methods :)

@midwestside1969 7 лет назад

Wow, I have watched a few of your videos in this series. You have totally demystified many of the questions I didn't even know how to formulate to ask. You have a teaching gift, Sir!

@UncleDoug 7 лет назад

Thanks so much, John. Rusty and I really appreciate your kind words.

@RadioWerwolf 5 лет назад

I love your handwritten and hand sketched tutorials. Your drawings are very clean and to the purpose. I would only like to express that if you are using two-diode setup, your transformer will have 2×V output, whereas bridge rectification requires only V output from the transformer, V being the desired output voltage. Since 2×V capacity transformer will have double the secondary windings of a V capacity transformer, it contains more copper and therefore it tends to be more expensive than the latter. Very informative video as always and thank you very much for it.

@UncleDoug 5 лет назад

Thanks for the nice comments and info, LS.

@RadioWerwolf 5 лет назад

@@UncleDoug thank you uncle. One stupid question: do tube rectifiers have voltage drop characteristics like diodes have?

@UncleDoug 5 лет назад

Not stupid at all, LS. Yes, they do.....because rectifier tubes contain two diodes, so all the same rules apply.

@Blaydrnnnr 6 лет назад

I know this is an old video but....AWESOME video! MORE! MORE! I learned a ton so quickly....I am 56 years old, with 9 vintage tube amps, and have been wanting to apprentice at a repair shop for years to try to learn more about circuit analysis on tube amps. There just arent any shops within a few hundred miles of me, so I try to pick up what I can on here. Great explanation! Cant thank you enough and really want more. ALL my amps need attention, but shipping a 65 lb tube amp costs a small fortune. So I'm trying to learn more myself.

@UncleDoug 6 лет назад

Thanks for your very nice comments, B. You have the right attitude.....It's always better to pursue independent ability than it is to rely on others. Best of luck with your self-education.

@jlucasound 10 лет назад

Thank You, Uncle Doug and Rusty. I was thinking I needed to go through all your videos, several times, to "wrap my head around" "IT". I am finding once or twice is clearing up so much that I didn't exactly understand. You (and Rusty) are excellent teachers. I Thank You again, dear Sir.

@UncleDoug 10 лет назад

You are quite welcome, JL. We're glad to hear that the videos are helpful and easy to digest (Rusty's favorite word). Speaking of whom, Rusty is actually the "brains" of the operation, I am simply his servant and provider of ear scratching.....in fact, that's my official title in our partnership agreement :)

@selectMATT 10 лет назад

I'm a huge fan of this channel. You're like the teacher I never had. Great video!!

@UncleDoug 10 лет назад

Thanks so much, Matt. I sincerely hope my videos are helpful and informative.....thanks for watching!!!

@bing600 7 лет назад

Thank you for the effort . Your videos are very instructive for us who are just learning about the old amplifiers. Greetings from Croatia.

@UncleDoug 7 лет назад

You're welcome, Robert. It's great to hear from our international viewers. Best regards from Texas, USA :)

@neilzspam 11 лет назад

This is great. Clear, concise, and very helpful. You obviously have a lot of knowledge about tube amps and it shows in all your videos.

@UncleDoug 11 лет назад

Thank you, DN. Over the years, I've found most explanations of electronic theory to be utterly confusing and overly complex.....even though the principles themselves are actually rather simple. After struggling to learn about these topics, I am now trying to "translate" them into basic language and make them more accessible.

@jeffb6161 8 лет назад

finally I understand rectification, Uncle Doug your the BOMB!!! give rusty a treat for me!

@UncleDoug 8 лет назад

+jeff b Thanks, Jeff. Rusty and I are glad the videos were informative :)

@dneitzke 7 лет назад

Thanks Uncle Doug. your sharing is a gift, stay with it, Your production is straight forward and professional. many Thanks!

@UncleDoug 7 лет назад

You're welcome, DN, and thanks for your very nice comments :)

@dneitzke 7 лет назад

Hey, No charge, I should be paying you and the Carlson lab guy, words are nice ,but sharing the knowledge base that has taken you years to develope, and to point blank share it depicts great character, You are a valuable tech. and part of what makes America great, down the road I may ask you on certain test gear, I have more than whats needed for my analog world , and a newbie i Iz. many Thanks Uncle Doug!!! P.S. gotta brag on my latest find, Stopped in at a garage sale cuz traffic was at a stand still and noticed a very familiar looking brief case. a barley used Sencore MU-150 with all the original tags, power cord still factory wrapped. they wanted it gone, and $5 made it land on my bench. replacing all the electrolytics (ESR thru the roof), as I write this. be well.....

@UncleDoug 7 лет назад

Congratulations on a major score, DN. I guess traffic jams are good for something :)

@lionelhodges226 10 лет назад

I find this gentleman an excellent teacher, I have learnt more watching these videos than any book that I have read. I would like to see how to use an oscilloscope and what voltage you can put into the oscilloscope with out damaging the scope or my self. Please keep these splendid lectures up and thank you. Lionel (uk)

@UncleDoug 10 лет назад

You're quite welcome, Lionel. I appreciate your kind appraisal. I haven't made a video featuring the oscilloscope, mainly because I'm not sure how many viewers own one, but I will definitely consider your suggestion. Thanks for watching and commenting.

@Rodedog55 2 года назад

Uncle Doug, . . . your videos are so educational and clear. Thank you for sharing your knowledge. Great Deal for us All.

@UncleDoug 2 года назад

Thanks so much, RD :)

@michaelpukmel9175 7 лет назад

Whenever I learn something new, I realize just how far Id like to go, thanks!

@UncleDoug 7 лет назад

You're welcome, Michael.

@areyouavinalaff 7 лет назад

and then there's kirchoff's laws and quadratic equation. backin' up, backin' up.

@areyouavinalaff 7 лет назад

in another video you mention the 12ax7 tube being two tubes in one. is this why the 12ax7 is more gainy than others further down the list such as 12at, 12ay etc? and also the reason why it uses less current?

@georgeg85 5 лет назад

You are such a great teacher. I feel smarter after every video 🙏

@UncleDoug 5 лет назад

Thanks, George. That's great to hear.

@johnmiller9219 3 года назад

Thank you Professor Doug for this rectifier lesson.

@UncleDoug 3 года назад

It was a pleasure, John.

@JohnBrown-vn2qw 9 лет назад

uncle doug you kick ass. thanks!

@UncleDoug 9 лет назад

John Brown You're welcome, John :)

@jexsmx6608 7 лет назад

excellent explanation. especially appreciate your run-down on tube categories and models.

@UncleDoug 7 лет назад

Thanks, Jex.....glad you enjoyed the video.

@Nobody92421 5 лет назад

You are doing the world a diservice if you are not teaching electronics / electrical engineering at the college level. I've take course work that I didn't understand until finding your channel. Just becuase you can pass tests doesn't mean that you "get it". NOW, I get it... ; )

@UncleDoug 5 лет назад

Thanks so much, TJ. That's great news.

@jtNuwanda 7 лет назад

8:03 - those two really don't look happy... ;) Great clarification, as always, Doug! Thank you so much for all your work!

@UncleDoug 7 лет назад

Those cathodes are definitely displeased about something, JT :) You're welcome.

@arcarioandsons 3 года назад

You sir are an excellent teacher!

@UncleDoug 3 года назад

Thanks Ben :)

@brucechamberlin9666 5 лет назад

Wow, what a good teacher you are! I understood and you made it seem simple and easy as well as provide practical advice. Now when I see a board, I know what the parts do! Thanks!

@UncleDoug 5 лет назад

You're welcome, Bruce.

@EUC_Senior 4 года назад

Very good explanation of rectification.

@UncleDoug 4 года назад

Thanks, Mark.

@shaunsanders9164 7 лет назад

Thank you, Uncle Doug. Just...thank you. This stuff is the bomb. I'm learning a great deal because you're a great teacher - clear and direct. Lovin' it! Thanks to Rusty, too.

@UncleDoug 7 лет назад

You're welcome, Shaun....from all of us :)

@edwarddemedeiros3607 3 года назад

Wow. I'm amazed and informed with every video!

@UncleDoug 3 года назад

Glad to hear it, Ed :)

@barrydavison8705 8 лет назад

thanks Doug. your part 1 amp video explains it perfectly . I don't how I missed it!!

@UncleDoug 8 лет назад

+Barry Davison You're welcome, Barry. I'm glad the video was helpful.

@onemancarnage 10 лет назад

Thanks again Doug....fantastic video, and thorough explanation. And thank rusty as well.

@UncleDoug 10 лет назад

You're welcome, Bryan. Rusty and I send our regards and sincerely appreciate your time and interest :) ^. .^

@michaelthomas9992 5 лет назад

Best explanation I’ve ever seen. Bravo. Thank you!!!

@UncleDoug 5 лет назад

You're welcome, Michael. Thanks !!

@robertbarcus2008 6 лет назад

Thanks for all your time in the information we definitely appreciate it

@UncleDoug 6 лет назад

You're welcome, Robert

@SamarthGoel 3 года назад

Hey Doug! Love your vids, I know about these concepts and watching your vids just makes all my doubts go away!

@UncleDoug 3 года назад

Glad to hear it, Sam. Thanks !!

@kevincourtney5934 9 лет назад

very informative and appreciated, you are a good teacher. thank you

@UncleDoug 9 лет назад

Kevin Courtney Thanks, Kevin. I'm glad the videos are helpful.

@Getdead23 10 лет назад

Thanks so much. Explained so well!

@UncleDoug 10 лет назад

Thanks, Kevin. I'm glad the video was helpful.

@f22at12mm 3 года назад

Another great video. Great explaination and teaching style, thanks so much!

@UncleDoug 3 года назад

Thanks, Scott.

@alexthefakest1279 9 лет назад

Dirty uncle Doug! Thanks for the video. MY kx15 crate amp was buzzing really loud, and there was something loose inside.I resodered the loose part, but I forgot which wires went where... now trying to learn a lot.thanks again, peace

@UncleDoug 9 лет назад

+alex thefakest You're welcome, Alex. It's good that you are trying to learn as much as possible to enable the repair of your own amps. That's always the best place to start. Best of luck with your project :)

@silasfatchett7380 Год назад

Always take a photo before dismantling a circuit.

@AlexanderBrevig 9 лет назад

I just wanted to let you know that you answered all my questions about the inner workings of an amplifier - this is true after I read the "Inside Tube Amps" by Dan Torres. Thank you so much! I'm ready to put my amp together now (I've had the parts for about three years, but I hate to attempt things I don't fully understand.) PS: Don't worry, I've built PSUs before and know about safety measures for high voltage high current, and cap discharge etc. Thanks again, excellent videos in layman terminology.

@UncleDoug 9 лет назад

Alexander Brevig You're quite welcome, Alexander. It's great to hear that the videos are helpful. Best of luck with your amp project :)

@christophbruhn7471 10 лет назад

Such a beautiful explanation.

@UncleDoug 10 лет назад

Thanks, Christoph.....I really appreciate your kind assessment. I have several other technical videos that may be of interest. Please check my most recent posting on Output Tube Biasing.

@worldwide1376 3 года назад

Super explanation! Thank you for posting.

@UncleDoug 3 года назад

Glad you enjoyed it, WW :)

@TAURELLIAN 7 лет назад

This is a superb explanation! Really made everything simple and easy to understand : )

@UncleDoug 7 лет назад

Thanks, Zach.....glad it was helpful :)

@donsizemore8746 7 лет назад

Really great video. You made this very easy to understand.

@UncleDoug 7 лет назад

Thanks, Don :)

@davidportch8837 8 лет назад

Thanks Doug - useful insight here - never thought about how an indirect cathode on a rectifier gives a more gentle HT switch on to the rest of the valves (tubes!) in the circuit eg allows the heaters to get working first...clearly a better option than a direct one!

@UncleDoug 8 лет назад

You're welcome, David. The difference is quite evident when using an indirectly-heated rectifier vs a directly-heated one. The first time I used a GZ34, it took so long to come on that I initially thought that the amp circuit was faulty :)

@yagobolivar5691 9 лет назад

Way less rippled! Thanks a lot.

@UncleDoug 9 лет назад

Yago Bolívar You're welcome, Yago :)

@gerryroberts662 6 лет назад

I've watched this before..its Good to refresh my memory..

@UncleDoug 6 лет назад

Repetition is good for recall. Thanks for watching.....twice :)

@robvaldivia9711 9 лет назад

Thanks Uncle Doug! You have a eliminated so much of my ripple lol GREAT VIDEO LESSON!!! (I will be watching this repeatedly)

@UncleDoug 9 лет назад

Rob Valdivia You're welcome, Rob. I'm glad that Rusty and I could smooth out your B+ :) Thanks for the kind words and best of luck.

@jameskeough4620 4 года назад

I always knew what filter caps did, now I know how they do it!

@UncleDoug 4 года назад

I'm glad the video was informative, James.

@jonmu8140 10 лет назад

Thanks for posting this. I've always enjoyed the sound of tube amps, and tinkering with electronics. Recently, I've been itching to building my own tube amp (but I don't play guitar ... weird, I know). Before I pull out the soldering iron, I want to understand more about what is actually happening inside the amp. It looks like I'll be spending a bit of time on your channel in the coming days.

@UncleDoug 10 лет назад

You're welcome, Jon. Hopefully the videos I have posted will give you a basic understanding of amplifier circuitry. Best of luck with your pursuit of knowledge.....and your project.

@baulaucheung1598 3 года назад

Uncle Doug, I have a few questions for you and please explain them : 1. What is 169VDC RMS !!!!? 2. What is pulsating D.C.? 3. If I need +270VDC, using a two-diode full-wave rectifier, how many volts should the transformer secondary be? 4. What is the P.I.V. of a diode? 5. What is 120Hz hum!!!!? 6. Why is a computer power supply so special that deserves a mention? Looking forward to hearing from you, Uncle Doug. Paul Cheung

@UncleDoug 3 года назад

I started to answer all of these, but realized that the answers are all readily available either in my videos or via internet searches. Good luck.

@GregsGarage 10 лет назад

I'm working my way through all your videos UD&R. You are hitting on all the topics I have questions about. It's like you're reading my mind. I understand the electronics from a numbers side, but never understood why "filter caps" were in audio circuits. This video filled in some big gaps for me. THANKS!

@UncleDoug 10 лет назад

You're welcome, Greg. I try to cover all the topics that puzzled me when I started out with tube amps.....and, apparently these topics coincide with other people's areas of uncertainty. Rusty and I are glad the videos are helpful :)

@kyugreywolf6801 7 лет назад

Absolutely brilliant explanation, thanks for the video!

@UncleDoug 7 лет назад

You're welcome, WW. Thanks for the nice comment :)

@PhuketMyMac 3 года назад

What a great YT channel

@UncleDoug 3 года назад

Thanks, P.

@bullet0657 11 лет назад

keep it up Doug. I am learning so much .Thank You.

@UncleDoug 11 лет назад

I will, Edwin. Thanks for watching !!!

@nelsonmedley4349 5 лет назад

Very Good explanation. Tank you very much.

@UncleDoug 5 лет назад

You're welcome, Nelson.

@bullthrush 11 лет назад

A very thorough explanation, thank you. After running some simulations in LTSpice, I completely understand your preference for the soft start of the GZ34.

@UncleDoug 11 лет назад

Thanks so much, BT. I'm glad that the GZ34 distinguished itself.....it's a great rectifier.

@foibster666 10 лет назад

Great work Uncle Doug!! Best subscription I've done EVER in YT! I'm hungry for knowledge, keep those awesome vids coming! Greetings from Greece!

@UncleDoug 10 лет назад

Wow....Thanks, Foibster. Rusty and I really appreciate your kind words of support, and hope that all is well in Greece !! :) ^. .^

@farmerwayne1404 4 года назад

Great explanation Uncle Doug! Thanks.... And as I like to joke abit, back in the day I had a bad bottle of "Ripple" and the next morning my head had a very large hum!! Ok, ok. I'll stop! Seriously though, Ive learned alot from you and greatly appreciated it!!🎼🎛

@UncleDoug 4 года назад

Ripple was the nectar of the gods back in the old hippy 60's, Wayne. I downed many a bottle of it while listening to Iron Butterfly and Vanilla Fudge albums ;)

@farmerwayne1404 4 года назад

@@UncleDoug Remember it well!!! Matuse White...

@PaulDonnaErik 6 лет назад

Thanks Doug! Your videos are excellent

@UncleDoug 6 лет назад

You're welcome, PDE.

@joepublic4069 5 лет назад

Awesome. Excellent presentation. Thank you.

@UncleDoug 5 лет назад

You're welcome, Joe.

@jamescarter4175 5 лет назад

Another great video. Thanks!

@UncleDoug 5 лет назад

You're welcome, James.

@AliKiani7887 4 года назад

very cool video, thanks uncle

@stephenward2777 10 лет назад

Great teaching!

@UncleDoug 10 лет назад

Thanks, Stephen :)

@maddoxinc1642 7 лет назад

Doug, this is a great explanation, best I've seen yet. If you get a chance to make another video, could you please go further into depth on tube rectifiers and how is it that we get the B+ off of the cathode. Also, how does the current flow through the anodes since it appears to be a seemingly open circuit. I'm assuming the anodes don't touch.

@UncleDoug 7 лет назад

Please check our more recent videos on rectification and power supplies, Maddox. They contain the information you seek.

@maddoxinc1642 7 лет назад

Thank you Sir, don't stop doing the good work you do!

@lornespry 3 месяца назад

Excellent - helped me a lot!

@UncleDoug 3 месяца назад

Thanks, Lorne. I'm glad :)

@rudynyc1 10 лет назад

Great video, very concise. Thank you so much Uncle Doug for posting. Subscribed.

@UncleDoug 10 лет назад

You're welcome, Rudy, and thanks for the kind words. Welcome aboard :)

@BoomerBends 3 месяца назад

Very well done!

@UncleDoug 3 месяца назад

Thanks, BB :)

@danielwelsh Год назад

Thank you….I kinda chuckled at the end….”I haven’t come across any old amps yet” …..haha, i bet you can’t say that now Uncle Doug

@UncleDoug Год назад

No, I've come across quite a few since this video.

@tronics666 6 лет назад

Thanks Uncle Doug! Well done!

@UncleDoug 6 лет назад

You're welcome, T :)

@michaelmartinez364 8 лет назад

This is a great video! Thank you for your explanation.

@UncleDoug 8 лет назад

+Michael Martinez Thanks, Michael. I'm glad you liked it :)

@VelezBiH 6 лет назад

Uncle Doug great lesson!

@UncleDoug 6 лет назад

Glad you liked it, V :)

@jeffb6161 8 лет назад

that 5u4 looks just like my 5z3p- cool, man i am hooked, long live the tube!!!!

@UncleDoug 8 лет назад

+jeff b The two tubes are quite similar in design, but have different numbers of pins and different pin-to-component internal connections, Jeff. The 5Z3 was a popular rectifier with early jukebox amplifiers.

@jeffb6161 8 лет назад

cool, did not know that, using the 5z3p in the Hifi with 2- 6N9P'S and 2-EL34-B'S, going to correct all my mistakes after watching some more of your videos 2 or 3 more times as to absorb all the info, happy holidays to you and rusty- sorry forgot your cat's name him too, take care

@UncleDoug 8 лет назад

Happy holidays to you too, Jeff, and best of luck with all your projects in the new year :)

@jeffb6161 8 лет назад

thank you, you are a class act my friend

@UncleDoug 8 лет назад

You're welcome :)

@ANWEsuigeneris 7 лет назад

Great video.

@UncleDoug 7 лет назад

Thanks :)

@stephenrioux6821 4 года назад

Hi, Unclr Doug, here's a good one. I'm rebuilding a Newcomb AV-7 phonograph with a Widow Maker circuit. It has a a 12av6, with dual diode and a triode in the same glass envelope. The diodes are connected in a half-wave configuration, and a solid state diode is connected in the heater section. I've seen a similar circuit using a single diode tube, and a SS diode in the heater section.

@UncleDoug 4 года назад

I tend to avoid the series-filament circuits, Stephen, but this one sounds rather unusual. Thanks for sharing it with us.

@stephenrioux6821 3 года назад

@@UncleDoug Thanks for all of the Videos, and for your reply. After weeks of study, and searching for an isolation transformer that never existed, I tend to concur. Current draw on a 'Widow Maker' is enormous. But it was a great case study in archaic engineering (and finding obsolete parts), and I did find an excellent source for schematics: ''Practical Amplifier Diagrams'' (Robin & Lippman, 1947). You, and your fan base, can download a PDF copy for free.

@MrTysonjharris 8 лет назад

Great video, thanks for posting!

@UncleDoug 8 лет назад

You're welcome, Tyson :)

@ScarTubeAmps 10 лет назад

Very nice video Uncle Doug.

@UncleDoug 10 лет назад

Thank you, ST. I really appreciate your favorable input.

@lanwanx 6 лет назад

very informative, thanks!

@UncleDoug 6 лет назад

You're welcome, LW :)

@francisking5164 7 лет назад

there are many great videos here that help tremendously. But what about repairs and identifying distortion and other enomolies in existing new and vintage amps?

@UncleDoug 7 лет назад

I have posted quite a few videos demonstrating diagnostic and repair techniques, Francis. Please check out my video list.

@elcochipit 6 лет назад

very usefull video! thanks Uncle Doug

@UncleDoug 6 лет назад

You're welcome, El :)

@jimmydavidson8174 6 лет назад

Great video!!

@UncleDoug 6 лет назад

Thanks, Jimmy

@matthewbrown5677 5 лет назад

Learnt something ...reliving on audiokarma. AKAI AA1175

@williamolsen20 6 лет назад

You are so cool Uncle Doug!

@UncleDoug 6 лет назад

You are so kind to say so, William. Thanks :)

@deltadada 8 лет назад

Great video, learned a lot!

@UncleDoug 8 лет назад

That's great to hear, DD. Glad you liked it :)

@timothyb1559 3 года назад

In videos I've watched the value of the filter caps is often greater than the original spec. Can I assume the value just needs to be enough to always have enough capacity to fill the ripple? Would substituting, say, 100uf cap instead of a called for 8uf be fine to use aside from being overkill and expensive? Thank you, Uncle Doug!

@UncleDoug 3 года назад

You need adequate capacitance to fill the ripple, as you said, but going too high will stress the rectifier tube on start-up, since big caps draw a lot of current to initially charge up.

@willstillill9591 2 месяца назад

thank you

@MSStateBulldawg83 8 лет назад

Uncle Doug, I very much enjoy your RU-vid videos on Vacuum Tube Design. Would you do a video that explains how a Tube is sized? Specifically, how is a grid sized to actually amplify & repeat a guitar signal?

@UncleDoug 8 лет назад

+Bulldogs#1 Thanks, Bulldog. To be honest, the size of the grid is really not an issue. The amplification is a result of current flow within the tube as moderated by the grid, but not due to the grid's size.

@user-rf9me7xm1w 3 года назад

Great explanation as usual but won’t an input voltage of 120v result in a peak voltage of 169 volts peak value ? It’s this value which should be shown on the diagram for both half and full wave rectification. Best regards.

@UncleDoug 3 года назад

Yes, but that opens the door for additional complexity, i.e. the concept of RMS vs peak voltage. To keep these basic instructional videos easy to follow, I have to include certain concepts and exclude others. The RMS vs peak voltage issue is covered fully in a different video.

@dachikhutsi2793 9 лет назад

thank you made it much easier for me !

@UncleDoug 9 лет назад

+Duche Khutsishvilii That's good news, Duche. We're glad the video was helpful :)

@JoelLaviolette 4 года назад

Thanks so much for these videos Uncle Doug. I'm hoping to get a better understanding of how to select the capacitance of the Filter caps when using rectifier tubes. Is there any chance you have any videos that talk about that? I've been told that you need to be concerned about the in-rush current because the Rectifier tubes can't handle too high and that's why the capacitance needs to be low. I can't say that I understand why higher capacitance would increase that current (but I am just learning).

@UncleDoug 4 года назад

When an amp circuit is first energized, the filter caps have to charge up, so for a second or two, they are like a dead short....the higher the capacitance, the longer the short lasts. The maximum value for 1st filter cap is given for each rectifier tube in tube handbook(s).

@JoelLaviolette 4 года назад

@@UncleDoug That makes sense. Thank you. I'm reading Megantz's book and he mentions that the final stage of filtering is the preamp section and that is because you want to filter it more. So is there a reason that we usually see all low capacitance caps in a row? Why not just the first cap low and then all the rest higher?

@noseonscent1935 4 года назад

great stuff!

@UncleDoug 4 года назад

Thanks, Steven :)

@Jako4460 6 лет назад

Thanks Uncle Doug!

@UncleDoug 6 лет назад

You're welcome, Jakob :)

@tub8r 4 года назад

Very informative. Thank you. I was actually watching this to find out more about chokes. I got Fender Greta and it has a choke the size of output transformer. Presumably, this choke after rectification works in conjunction with and complements the filter caps.

@UncleDoug 4 года назад

Thanks. Yes, filter chokes very effectively reduce the ripple in rectified DC.