All You Need To Know About AMPLIFIERS To Fix Stuff - A Beginners Guide To Audio Amplifier Repair

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NOTE TO BEGINNERS This video is suitable for anyone with at least a basic knowledge of electronic components, particularly Transistors. If I covers topics here that you are not familiar with I strongly recommend you watch my other videos in the 'All You Need To Know About'.. series first. In particular 'All You Need To Know About Transistors To Fix Stuff'
You will find the other videos in this series here:
• The ALL YOU NEED TO KN...
Mentioned in this video - No oscilloscope? No problem!
You can use a pair of amplified PC speakers or similar to aid in fault finding amplifiers
• How to test GPU / CPU ...
(Northern Soul) Music in this video
David And The Giants - Ten Miles High
Hill Audio DX3000 Schematic and Service Manual
www.badcaps.net/forum/showthr...
CHAPTERS
00:00:00 Introduction
00:08:10 Amplifier Classes
00:10:33 Class A Amplifiers
00:17:34 Class B Amplifiers
00:24:52 Class A/B Amplifiers
00:29:47 Class G & Class H Amplifiers
00:42:10 Bridge Mode
00:45:40 Class D Amplifiers
00:50:21 Test Equipment
1:04:38 What Goes Wrong
01:24:09 Practical Example
01:43:33 Epilogue
Learn Electronics Repair #236
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Retro Upgrade - / @retroupgrade (Carlos)
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Equipment used in my videos. These are affiliate links, you pay the normal price and I make a small commission.
TEST METERS
Aneng AN8009
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MESR-100 ESR METER
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XC6013L CAPACITOR METER
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TM-902C TEMPERATURE METER
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PCI POST ANALYZER
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TL460S Plus PCI_E ANALYZER
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MULTIMETER PROBE KIT KET05
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OSCILLOSCOPES
FNIRSI 1014D
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FNIRSI DSO-TC3
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FNIRSI DPOX180H
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BENCH PSU
NPS3010W
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SOLDERING
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PROS'KIT SS-331H
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THERMAL CAMERA
Infiray P2 Pro
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MICROSCOPES
Amscope Optical Microscope (copy)
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ANDONSTAR AD407
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EEPROM Programming
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CH341A
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Thank you
Richard

Опубликовано:

24 июл 2024

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Комментарии : 368

@LearnElectronicsRepair 2 года назад

A couple of points: As a few people noticed I mixed up the terms peak voltage and peak-to-peak voltage a few times in this video. I do know the difference it was just me having a bad day 🤐. If you noticed the mistakes then I hope you can skip over that and relax in the knowledge that you are correct 😉 Another topic that I did not mention, because I was looking at a PA amplifier, but is very relevant to Amplifier repair especially when it comes to the 'home stereo' type amplifiers from the 80s and 90s (but other decades too). If you have one or more these symptoms: * an amplifier with the voltage rails present but no sound output on one or both channels * intermittent audio on one channel or both *it works on some audio sources but not others * one channel lower volume than the other (or changing volume by itself) *crackling, popping or other (often intermittent) noise on one channel or both Then the most likely cause is the input select, mute and/or speaker select switches that are causing the problem. Usually these are multi pole rotary or push button type switches and the internal contact become tarnished with age. In my experience the only way to fix this (reliably) is to remove the switches from the PCB, carefully dismantle them, and clean the contacts. Usually replacements are not an available option and this becomes more a restoration job than a repair job.

@twobob 2 года назад

yeah I noticed but w/e it easily corrected in our heads. Are you sure it wasn't a secret test ? hehehe. Thanks

@ScottGrammer 2 года назад

It happens. Don't sweat it.

@searchin4music Год назад

I´m strongly with Scott Grammer on this: We all make mistakes man. But there aren´t many people in the world who can do what you can. Be proud of your skills, try to learn from mistakes - the only real mistake is to never even have tried, be gentle with yourself.

@BigRedGevo Год назад

I believe you're able to add corrections on videos with on-screen text input.. just food for thought, although it then just becomes a tedious task to satisfy the needy and greedy folks that feel their balls tickled with a feather anytime they hear such horrendous inaccuracies and MUST ASK FOR THE MANAGER lol just messing

@anthonydallarosa8314 9 месяцев назад

@@BigRedGevo😂 too true

@wildchildjd2 Год назад

I have been repairing audio equipment for 30 years in a shop and at home and I feel like you did a great job on the explanation in your video and think it's amazing that you're passing that skill on to other people

@Padraigp 8 месяцев назад

Where have all your kind gone youre impossible to find. I have ten things need fixed and just going to have to learn how on the weekends cos nobody in ireland seems to do it any more. No harm to earn we will all need a ham radio when the apocalypse really gets into swing.

@Steven9675 5 месяцев назад

Zombies don’t use radios, so ….. little use.😊

@johnprescott6614 2 года назад

I really don't think you can find a better guide to audio amplifier repair on RU-vid.

@LearnElectronicsRepair 2 года назад

Thank You! 😀

@jeanious2009 Год назад

Agree, I subbed immediately!

@puresoulg Год назад

Indeed 👏🏾💯

@andrepretorius4702 Год назад

3 years of EE studies and then one hour on RU-vid

@Kushalien51_nv Год назад

Uncle doug joined since 2010 check him out

@seeithappen1 2 года назад

We love the way how you approach electronics repair - no fluff but direct to the core of it. Another great video - thanks for uploading.

@LearnElectronicsRepair 2 года назад

Cheers 😀

@yousufsait Год назад

Excellent. The effort that this man is putting into his videos is excellent. In today's world time is the best thing that you can donate and this man with all his experience and knowledge has given us exactly that. Let's all appreciate that. Thank you, sir, you made my day (or days).

@magnustorque5528 2 года назад

Absolutely brilliant video. You have managed to clearly describe how all of these amplifiers work in such a way that anyone with a little concentration and some basic familiarity with electronic components can grasp it all. Many thanks !

@dalexdba1 2 года назад

I have learned so much from this! Thanks for taking the time and effort with the various classes of amps and operating principles into something I could follow. You are an absolute star my friend!

@Transistorfanatic 2 года назад

What a great teacher a great sense of humor as well you explain theory trouble shooting technics what to look for and how to go about it OUT-Standing

@Phantom4416 2 года назад

You are indeed an amazing teacher. I applaude and thank you for the great deal of effort and dedication you put into producing these valuable videos. Thank you so much

@repairfreak Год назад

What a great video, been repairing electronics for 30+ years. I always appreciate anyone that can explain the difference between the different classes of amps. There is just so much to learn when repairing audio amps. Even after 30 years I’m still learning. To all you newbies.. never give up and learn all you can! Peace out.

@robt7785 Год назад

I repair 50 to 100 amps a year and I still picked up a handy tip or two. Thanks! Subscribed!

@davesdigitaldomain 2 года назад

excellent video Richard, it really helps when you explain how the circuit works. When you know how it works you can fix it. This truly is the best channel on RU-vid for learning electronic repairs, because most channels are just watch me repair type videos. I've learnt so much from you Richard a big thank you for sharing your knowledge and experience.

@MikeSims70 Год назад

You are a talented teacher! This was a great video and I especially loved how you went through the design differences between the different classes of amplifiers. I learned a lot in terms of troubleshooting that I didn't know before and understanding how the different classes are designed I can see is essential to being able to troubleshoot effectively. Well done! Excellent video, and THANK YOU!

@gordthor5351 2 года назад

Thanks for taking the time to explain in detail how these amps work.

@romancharak3675 2 года назад

Your explanation along with your hand-drawn circuits opened my eyes. Thank you for your time and knowledge.

@LearnElectronicsRepair 2 года назад

You are welcome

@davidharvey4803 5 месяцев назад

Thank you so much. I have been in electronics repair for 45 years. DC coupled circuits are sometimes very difficult to repair. This video is very good for anyone who is just starting to get into audio amplifier repair and a good refresher course for us old timers as well.

@whkiess 3 месяца назад

Thank you for this most detailed description of the various classes of amplifiers, how they work and common faults. Amps have been a mystery to me for decades. I used to be in various bands and built some of our own equipment. This helped me in understanding & diagnosing an old Playmaster 300W Subwoofer amplifier from Electronics Australia Magazine May 1995. It exhibited the symptoms you described precisely. It's a pity these videos were not available at that time, they could have helped me fix it then rather than buying/building another one. I think the transformer used in the video to invert the audio signal is a stroke of genius. It could probably have been done using op amps/ transistors, but I'm sure they had their reasons for going down this path.

@magnuslilleberg1941 2 года назад

If my electronics teacher back in the days was anything like you, I might have actually finished the semester! I really enjoy how you go about this in a most practical manner - Of course, knowing the inner workings of semiconductors down to the atomic level can be interesting and all, but at the end of the day does little to nothing to help you breathe life back into some dead/crippled apparatus. Keep up the good work!

@alexandrunicolaepascu9958 Год назад

Top

@DaddyPsyMonn Год назад

I've been a similar situation, Back in 93 I wanted a HAM Radio License, but the guy teaching the course preparing you for the Exam, made it unbearable, I learned nothing, didn't get the license, cost a small fortune.

@k9er233 Год назад

@@DaddyPsyMonn Many people have loads of technical knowledge but are clueless about how to teach it to others. Unfortunately, many become "teachers" and "professors". This gentleman is very adept at passing on his knowledge. I am very happy to have found his channel.

@fredlindberg Год назад

Brilliant! Thank you for doing this! Theory + live exercise all in one video. Learned and thoroughly enjoyed!

@Jonathan_Doe_ 8 месяцев назад

Ended up answering my own question from my comment yesterday, the topology Peavey used in mkiii’s/mkiv’s etc is “quasi-complimentary”, and they did it due to high power NPN’s being better/more reliable at the time. A video on how these work would be a great addition to this series! Thanks for all the amazing videos btw!

@chriss.8379 2 года назад

This video and explanation really came in at the right time for me. It just happened that I have an amplifier on the bench to repair. No audio out on the speaker terminals. The power rail is good. I have schematics but was a bit of researching without realling knowing where to look at. With your video I'll probably diagnose it in a more structured way. By the way, it is an AKAI AA-1135, back from 1980.

@LearnElectronicsRepair 2 года назад

Hi Chris. good luck with your repair, I hope this video helps you. I had a quick look at the service manual. With an amplifier of that vintage, bad contacts in the front panel input/signal selector switches is a very very common problem so keep that in mind 😉

@djsherz Год назад

What a great channel! I've been repairing kit like this for decades, but this video has reminded me that every day is still a school day - some handy tips there, thankyou! Talking of a belt & braces approach to testing, I like to stick a voltmeter across the speaker outputs of an unknown amp before connecting the speakers, just in case there's a full 70V just waiting to fry my test speaker! ;)

@dladelle 2 года назад

Nice video. I have been in the repair biz for many years and learned a lot from this presentation. Thank you.

@SH-vv7zq 2 года назад

Thank-you for spending a large investment of your time producing this video. I've watched it all and have learned a massive amount from it. I love tinkering with 'dead' amps from the 80's / 90's and your tutorage is just spot on! Thanks again :)

@LearnElectronicsRepair 2 года назад

It is true that my more recent videos are taking more time to make (and I also think they are of better quality and certainly more ambitious) but as it so happens I really enjoy making them, it's more like a hobby than a job to me so just sit back and enjoy 😉

@chuckbenedict7235 2 года назад

Outstanding content regarding amplifier topology and then fault finding using that knowledge in one video. A master class, really, in a "short" 1hr 45min. I have a blown guitar amp and now feel like I know how to approach fixing it. Thanks!

@LearnElectronicsRepair 2 года назад

Oh for sure I know how to make 'short' videos LOL. Great to see you enjoyed it 😁Good luck with your repair, let us know how it goes. Also can I suggest the LER discord server - it is a great place to post and discuss your own repair jobs with others Learn Electronics Repair is now on Discord! Come and join the fun, it's free. discord.gg/vam6YC8vwU

@HawkFest Год назад

I'm not into electronics, but I'm currently shopping for a new system, and this was quite enlightening! Thank you very much, sir.

@briansilcox5720 Год назад

Great job... subscribed. Just starting my 1st solid state amp project, learned a good deal of what I need to get started. Thank you!

@RingZero Год назад

My favorite topic. I used to build custom amps in the 80's using 2N3055 transistors. Philips was a tried and tested circuit at the time.

@Fanan67 2 года назад

Once again, every minute of watching this video was worth it. Now I know the working principles of amplifiers. Thank you for dedication on teaching very clearly.

@LearnElectronicsRepair 2 года назад

Thank you - I hope you can now start repairing them 🙂

@fabiomalhao5230 2 года назад

Thank you so much for your master class. Would it be possible to have a video about matching transistors and HFE? I think that calibration and gain in amplifiers would also be interesting. You are an amazing teacher!

@marekwaczynski3894 11 месяцев назад

I have to say I've never got so perfect lesson about amps philosophy in 1,5 hour. This was invaluable. You should write a books - you maybe would be rich person. I am just renovating DENON 525R amp from 80-ies. And this gave me nice basics to understand what I am doing now and for what I should look for. Thanks a lot and now I have listen next movie. Perfect lesson. Thx. Marek/Poland

@christianskogsrd6222 2 года назад

Great basic guide. Looking for something like this for 2+ years......explaned everything i have been trying to understand about how amplifyers work and how to fix them... Thank you sir.....👏👌

@LearnElectronicsRepair 2 года назад

You are welcome

@andyjackson3891 2 года назад

Another wonderfully clear and concise video, Richard. Thank you so much for making and posting these. I thoroughly enjoyed that one.

@LearnElectronicsRepair 2 года назад

Hey that's great to see you enjoyed it 🙂 Of course I only do concise at 1hr 45 mins LOL

@davematthews414 2 года назад

Awesome video, great information, really well presented. Just another day in the shop for you, Gold standard education for us! Thank you

@DavidBeaver2112 Год назад

Thank you. That cleared up a few grey areas for me. Interesting amplifier for sure, especially with the TDA20XX series pre-amp ICs.

@joerenton8499 Год назад

Your a very clever man, years working on the bench and knowledge all makes a great teacher. Cheers mate

@EVILUTION9 Год назад

This Guy is a fecking legend! I have a basic grasp with electronics, but the amount of useful info I have taken in just by watching 3 of his videos is crazy.

@MrZerohour1967 2 года назад

Thank you, so good to hear the wealth of information you have. Love the explanation of the various classes.

@bramcoteelectrical1088 Год назад

I used to run a hill dx3000 was an absolute beast!! Hill audio sounded lovely and used old skool mofets. Lovely warm sound 😊

@DaveFulmer22 Месяц назад

been looking for a video just like this for weeks now, this is amazing. You explain everything in a way that makes understanding it intuitive. Thank you legend.

@malcolmboyley2334 2 года назад

Thank you Richard for an excellent presentation. I thoroughly enjoyed the learning experience.

@gwcoolduude 2 года назад

IMAGINE , I watched this vid with a larger some kitkats and a packet of cheese an onion crisps (Tesco multi packs) for an hour and 25minutes ,then saw you SEE the fault , sort it out and then play a Dave and the giants number ...... I enjoyed every bloody minute of it . you legend you!!!!!

@surreygraham6714 Год назад

Just watched this from end to end. Absolutely fantastic explanation. Thank you for sharing.

@garrettgiuffre7710 Год назад

Somehow I fell asleep for 12 hrs with this video on repeat. I can't help the overwhelming sensation of wanting to disassemble broken amps and do things I didn't know were possible yesterday.

@spudpud-T67 3 месяца назад

subliminal amping

@Poppinwheeeeellllllieeeeez 7 месяцев назад

Thank you for producing this video and series. Excellent presentation of the types of amplifiers.

@RCook-iy4xk 2 года назад

You covered a lot of material and I think it's the best video ever about and the repair of amplifiers. I like your video's very much.

@LearnElectronicsRepair 2 года назад

Wow thank you! There is some stiff competition from some very good creators out there in YT land. 😊

@slugtheslayer Год назад

Thanks Richard for expanding my electronic knowledge, my brain 🧠is a bit fuller now, cheers.

@kennyrmurray 9 месяцев назад

What a great job you do explaining these things. Thank you! Like I said on one of your other videos is you should try to explain how to build a VFD from single to 3 phase electric for us Americans with only single. I think that video would do great!

@JK-pv6tu 2 года назад

Wow I watched your psu video this morning and now came back to see if you have any amplifier vids, low and behold you just posted one!

@LearnElectronicsRepair 2 года назад

I like to listen to subscribers and several asked for it since the 'AYNTK about Transistors' video few days ago, so I took the first opportunity I could. I hope you enjoyed it. 🙂

@aa-fo5ou Год назад

Me lad I thank you for doing a super job on how the different class of amps are designed 👍 Only if my teacher in class was like you I would have been a better tech and would have made my electronic career much easier over all My hat goes off to you You are the best keep up the super work. Ot takes time to do these videos I thank you from the bottom of my heart ❤ Thank you again . Cheers 🍻

@entoletao Год назад

You are fantastic. Love your video. I usually get bored and never watch them till the end but your video was so entertaining with practical information that I watch it till the end. Please post more videos. thanks!

@davidhollfelder9940 Год назад

Back in to 70s, we built what’s now known as “bridge” amps, and called them “reverse phase double push pull”. For the class D amps, we called the sampling “quantizing, or A/D and D/A, and or “codecs/processing” .. very common now with digital communications in use today.

@davidshertzer900 6 месяцев назад

Thank you so much for this very informative video! I learned more from this video than some classes I've taken.

@tyronearendse1722 2 года назад

Hi friend thanks for the informative video and this is the best layout for amplifier classes I have seen so far. Thanks for taking the time to do all the videos, it is much appreciated

@SS-mj2mq 2 года назад

Thank you for taking the time to share 🤗💖💯👏👏👏👏👏

@kiklop2715 2 года назад

the best electronics channel without question. looking forward to all you need to know about mosfet video

@LearnElectronicsRepair 2 года назад

Oh, it's coming.. you won't have to wait too long 😉

@matthewbrown5677 2 года назад

My son has vintage Akai gear . AA1175 dual Mono amp. Very nice video

@ThomasBock-pm5ll Год назад

Just found your channel. Great video! Looking forward to learning more about diagnostics and repair.

@pronga510 Год назад

Thanks a lot for putting together this video and going so much into all the details - I learned things and it was very pleasant to watch! :)

@simonmavity180 Год назад

Top notch mate! I may go back to try repairing again thanks to you!!❤

@franciscorompana2985 Год назад

I wonder how I came to this side of the internet? Actually learning a bunch. Congratulations from Portugal 🇵🇹

@ruimvp 2 года назад

Great video. What a class. Subscribed 3 videos ago. This is the kind of information that I seat and watch until the end.

@LearnElectronicsRepair 2 года назад

Welcome aboard Rui 😀

@ruimvp 2 года назад

@@LearnElectronicsRepair pleased to know you

@paulf.5261 10 месяцев назад

Thanks🙏 I have recently found a old Technics amp at my local op shop. Got it home and it didn’t work.... I opened it up and looked for anything obvious and saw a blown fuse. Got the new fuse, and soon as I turned it on there was a flash of green light and a newly blown fuse. Unfortunately I don’t have the skills or the tools to go any further😞 I find it sad that no one fixes audio gear anymore.... certainly no one where I live in W.Australia. I also have a Cambridge Audio unit....I think called One🤔 anyway that one I was given because it was broken. I discovered that although it turned on and appeared to function I couldn’t get any sound out the speakers🤔 In a flash of inspiration I connected my headphones and was surprised to find the sound was coming through them just fine. I’m sure one day I’ll ask someone that can help me get them working😉🙏

@WindellChapman-kf4wr Год назад

Thank you sir ...this stuff is GREAT . Certainly helps clear the cobwebs from this old noggin !!!

@tasoscyra2785 2 года назад

Thank you so much!!! Thanks for sharing your big knowlege with so simple way!

@cavanmccann2134 2 года назад

You are a great teacher. Enjoyed this a lot!

@forogonya-howcometoyou5727 8 месяцев назад

Very practically oriented video, liked the way you imparted knowledge.

@B.Wildered 4 месяца назад

Cannot thank you enough for this generous gift of time and knowledge.

@davidotto7666 5 месяцев назад

Hey bud how you doing I just want to say that's pretty cool to see you work on a real real amplifier that's when they made an amplifier like the one you're working on it is such a pleasure to see something like that thank you

@jonhoyles714 2 года назад

great video just what i needed for my RF project leaned alot from this video very helpful. question i have regarding components and cheap china transistors there not as good as some of the originals can be quite tricky finding the good ones like 2n4427 and 2sc1974 any clues weres best to buy from ?

@chikaBurton Год назад

Great video, with great explanation. Now, a question: when it comes to designing an AB class amplifier, is it better to do a traditional complementary pair or to do what those guys did? I think it would be easier to find matching transistors of same type (NPN or N-channel MOSFETs), than match complementary pair by gain and base bias, at the cost of a little bit of added complexity (which should not be a problem with opamp preamp stage nowadays), but I'd like to hear your opinion(s).

@codebeat4192 5 месяцев назад

Nice video, you explained it very well. At the Class D topic I think it is a little different, it is not PWM (Pulse Width) but PHM (Pulse Height), following the height at a fixed frequency. I my understanding the amplification operation is closer to AM than FM. Amplitude Modulation instead Frequency Modulation. PWM is Frequency Modulation/Modifcation, it changes the time between pulses of the same height to reduce the voltage by reducing the on or off in length of time. That is not what you want if you want to reproduce an audio signal because otherwise it will change the frequency of the audio (or other artifacts). You can compare it with switching, a carrier wave, constant samples taken from the audio at a fixed frequency (for example 260khz, far above hearing limit). Because of the (carrier wave) frequency, the output is not constantly on like 100% and that are the savings. This is not PWM, the width of on/off is constant, this is switching/oscillating at a frequency, like a microcontroller or CPU do with use of a crystal (that is why D is classified by some people as Digital). With use of switching it follows the height and lows of the incomming amplitude like other amps do but only a fixed periods of time. That is the difference. At the end of stage it uses a low pass filter to filter the the switching noise/carrier wave.

@FireandFrostHVAC 2 года назад

That is one big assed amplifier... thanks for sharing your wealth of knowledge and the great video. 😀

@assistantto007 Год назад

Thanks, your videos are great. If you happen to see this, can you recommend an effective but relatively affordable way to test the values and esr of capacitors while in circuit? I'm led to understand that testing capacitors in circuit requires rather expensive devices..

@alexandrefernandes6286 11 месяцев назад

Sir, what a great video. I've learned tremendously from it. I'm now a subscriber. Thank you sooo much for sharing your knowledge.

@mahmoodsaraf1 2 года назад

Excellent video , thank you and God bless you....

@bombastic6575 Год назад

I watched entarily video like a good movie. You did the great job explaining everything. The light bulb method is simple and genius in the same way. Now I know how to properly diagnose and repair the amplifier. Thank you very much for sharing your knowledge ❤

@ampuh214 2 года назад

Wow. A great video. Thanks for your work, i have a amplifier to repair. Congrats for 23k subs btw

@stevenverhaegen8729 2 года назад

Excellent and clear, these class distinctions ! 😀👍😎

@ferencszabo3504 Год назад

The best AMP explanation EVER !

@nitroboy2 Год назад

very good teacher , i didnt get everything the first time , but ill watch the vid again in couple days .

@timbrown9305 Год назад

We have the worst instructors (teachers) in the United States. We spend more than any other country and our children are more ignorant than ever. THIS guy has just schooled every teacher out there. Amazing presentation... and how you anticipate the questions while I am formulating them is absolutely amazing.

@thefloop2813 4 месяца назад

We have teachers that like to make things seem complex to fuel their own ego's. It's a hugely rampant problem in the American public education system. It doesn't pay good, so it tends to attract people who never had the power they wanted over other kids when they were in school, and it attracts people who are addicted to making themselves feel intelligent. Very rarely anymore does it attract anyone who actually wants to help a child learn something. Most high school teachers hate the children they teach because by the time theyre that age, thanks to all the other crappy teachers, and the crappy parents, they are unteachable overly aggressive baboons anymore. Every single teacher i had growing up that wasn't garbage got out already, and aren't going back.

@markuren442 Год назад

Fantastic video. Well presented and very informative.👍🏻

@floydloonie4880 2 года назад

Thank.You.for.sharing.your.troubleshooting.skills.with.us!

@sadunnakipoglu9471 2 месяца назад

Congratulations, Thank you and appreciate your effort. Greetings to you from Turkey .

@barrylavanway-cutler6129 9 месяцев назад

I've said this before but I feel it is worth saying again. I've gotten more from your series in real world electronics than I've gotten from the AOE

@kittyhawk9886 2 года назад

Excellent work. Thank you.

@keithdownes2554 Год назад

Hi Richard, good videos. I am just getting into electronics amp repair. The mains input is ac goes through a rectifier to dc. So does the pre amp of a channel run on dc power with an ac input (guitar). The power amp on dc but the output amp on ac power. I have just retierd and won't to get into repair but need to understand before I start probing with my meter..thanks for the videos..keith...

@Dutch_off_grid_homesteading Год назад

Heya as I'm a beginner elektronics repairs I didn't even noticed it that's how many I still have to learn but your explanation is great I still understand it all the rest of the circuit you didn't explane is still darkmatter I really have to watch more video's from you to learn more but that is a matter of time

@PabloA64 2 года назад

Great video! It get me veeery much years ago in memory!:)

@LeeAudioAddictz 4 месяца назад

wow this is the best explanation of this ive seen in any video , Thank you very much i have learnt a lot from this ... and you have gained a new subscriber .. much appreciated

@lookoutleo 2 года назад

Very interesting, always wondered what the difference between class A and class b was,

@Arkasai 2 года назад

You're my favorite professor on youtube university.

@stephenbarlin2314 Год назад

Very good explanation and demonstration

@MrFujack103 Год назад

Great videos as always. I have a question. I have a brand new Bluetooth speaker that plays but has a crack/static noise that you hear like someone is touching a live to the speaker wire for less then a second at a time but it happens ever like 5 seconds? Any ideas I was going to use a thermal camera but it’s not when it heats up it does it right away??