Tube Audio Amplifier Troubleshoot Repair and Modification
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- เผยแพร่เมื่อ 5 ก.ย. 2024
- See a very thorough, in-depth repair and modification of an old Thordarson T20W40 tube amplifier. This includes the "thought behind" the modifications, and schematics as well. There is a description behind the troubleshooting process as well as another description for the failure points.
Check out the Wayward Hearts here:
• The Wayward Hearts - A...
*HEY! Check out their new Album, this is their TH-cam Channel:* th-cam.com/channels/RfzHcNCRwDC_dlRGKOUZEw.html This amplifier is "heavily" used in it: *To purchase their music, and support their band, go here:* itunes.apple.com/ca/album/high-impedance/id1222351741
Mr Carlson's Lab You are the GOLD STANDARD for this type of TH-cam channel. Period. Mic drop.
BobEckert56 I agrees entirely. Extremely informative, dense but not overwhelming, and very entertaining... gets me through those days I can't hit the lab, Mr Carlson keep up the great work!!!
Nice video. Im hapy here from Norway. Thanks
Not sure how to use “reply”
Someday I hope to understand all this stuff you are talking about. So extensive. So in depth and thorough.
Dr. Carlson is amazing. The knowledge he has amassed qualifies him for an honorary doctorate
Completely agree! Wish that were how it works! lol
He teaches the masters
I'm a child of the 50's and my dad was a radio technician among other things. Our funky, detached wood garage was his lab and it was filled with oscilloscopes on shelves just like your lab, Carlson. Dad's long gone, but your videos have brought a big part of that back to me. I am overwhelmed at your knowledge and expertise and your very clear explanations. Thank you.
How does one keep equipment like this stored in a detached building with no heating / humidity control? Do you have any tips, or is your local particularly favoring to this type of thing?
I am just awestruck by your attention to detail... right down to the added jack; handmade, hand painted, and stamped. Looks exactly period correct. You'd never know that it wasn't a factory original part! I just didn't think such workmanship and care existed in today's world. And don't get me started on your capacitor bank! Every. single. detail... perfect. Those soldering joints!!!! I've been soldering for 40 years, and thought I was a dab hand. Yet I could never make such consistently gorgeous joints! Mr. Carlson, your work is just jaw dropping. I really hope that someday you'll take on an apprentice to pass your skills on to another generation.
This is a "repair" which strains the definition of "repair!" It is the application of modern theory and common sense to a lovely old amp which had seen hard times. It will now be the centerpiece of a modern group in a different world... and will represent its age extremely well. Hats of to Paul again on an excellent set of values applied to a difficult job.
1959 1962 I took electronics at George Westinghouse Voca Tech HS Brooklyn NY--We studied Theory and built an
vacuum tube Volt meter, vacumm tube HiFi AMP, AM/FM radio, troubleshoot and repaired TV s------Teacher name Mr . Wellman
You did more instructions on theory and troubleshooting in this session than I was able to learn in those 3 lovable
years. I Love you man ---Budweiser for you.
Hi Robert. I'm an alumni of same high school 5 years later. The teachings there took me though a life of seeing and not fearing circuitry in it's mixed forms and through playing with automotive electronics as well as computers. Bless those teachers sharing their knowledge and their tolerance to teenage pranksters. And Mr. P Carlson of your invaluable knowledge, many thanks !!
It's refreshing to see a true master at work, it's very rare in this world these days.
Well i don"t need anything fixed 'yet'...lol.. but i wanted to compliment you on these projects..I am not only impressed, but I'm amazed at your knowledge base on all this work... I'm only an electronics enthusiast but I love listening to your explanations, diagnoses..and repairs on these jobs... and honestly I'm even amazed that you know everything that you do because you look so young to have such an excellent command of the educational teachings and video production aspects of everything on your channel ....not to mention your organizational skills of everything . ... I've had much fun here and look forward to more videos from you ...Great job..thank you
Glad your enjoying the video's, and thanks for the kind comment!
Mr Carlson's Lab it was a little difficult for me to follow because sometimes you speak very quickly for me as a foreign language. I enjoyed it a lor, anyway
@@MrCarlsonsLab , As a teacher, I must say you speak well... except for the things which almost everyone slips on... the "dead" use of adverbs. The "ly" is left off of almost everything these days. Also, a few extra words are added which don't make things any more clear. All in all, your grade of A+ is well deserved!
Mr Carlson the tube amplifier from the 30s is cool
I'm a young EE, I am a tube enthusiast and I must say I you have taught me some of the most professional work habits I now use day to day.
I've just watched this presentation for the second time, (two years later) , and I'm still in ore of your skill, knowledge and artistry Paul.. At least this time round I had a better understanding of your methods and analytic style. I know I'll never be in the electronic comfort zone that you have found, but your example will inspire perfection in the next generation of electronic engineers.
I know absolutely nothing about Electronics especially engineer electronics and I am hooked to this channel you are fantastic
While a ground floor education in Electronics is always great..for those (like myself) that don't have a formal education and am going in a 'round-about' way to learn @1:55 .... your method is the most valuable I have found and you're the person I promote to young people I know. A major bonus is you're not trying to 'appeal' to anyone with pop culture garbage wedged in to 'keep attention' spans. This amplifer was a real rare gem to see thanks so much. Human invention is quite the impressive thing when it's a true open market.
Thanks for your kind comment!
Another good video. I'm a retired Electronic Design Eng., and at 75 years of age, guess what, I'm still learning. Great work...
Wow great video! That old amp probably sounds better now than the day it left the factory. The protection circuit that you designed and built is a real stroke of genius. Your care and attention to every little detail is very impressive and not likely to be equalled by others. Great job!!
+Dave Mckim Thanks for the kind words Dave!
This is the most sophisticated analog tube start and protection circuit on the earth. Ingenious.
Very professional arrangement for the big caps - nice
Your skills are beyond planet Earth !
Thank you for such an in depth video.
+Hendrik Hendrikson
Thanks for the kind words Hendrik!
@@MrCarlsonsLab they"re right"'
now how"bout building a ribbon tube mic,, i"m only kiddin" Thanks,,
@@torreslarry6837 Not at all - Good idea! " Many a true word spoken in jest!"
I learn more electronics here than in college... You are one of best electronic guru's out there with videos that i never get tired of watching. Thanks for posting :D
Thanks Rene!
This is what makes an engineer an artist !!!
Your knowledge is unmatched. You forgot more about electronics than I will ever know
Wow a 30W class-A amp from the thirties! Impressive! Mr Carlson, as being a retired teacher with 40 years of
teaching experience, I would say that your teaching style is very attractive! I love the way that you mix good old
analog equipment with modern digital ones. The "push one knob" measuring that you can do using today's
oscilloscopes puts the student in a situation where they really don't understand whats going on. The old analog
scopes are harder to use, but you really know what you are doing! In the video you measure the power output
from the amp delivered to an 8 ohm load. The power measurements was carried out by some kind of HP-meter. If you do
the same in in another video, a discussion of measuring the power delivered by a sinusoidal shaped signal compared
to a nearly square wave shaped signal would be nice as I know that my students had problems doing the math for the
two signals. (I mean in the video, the computer in the HP-meter was doing the math!).
Thanks for your comment and input Ulf!
Impeccable Paul. I do the exact same thing before applying ANY power. On the machine I work with (2" quad video tape machine) I usually unplug the various power supplies, pull ALL the Modules from the machine. Video head assembly and remove anything I can remove! I Make inventory of all circuit cards and label them with paper tags amd carefully place them in a special box. I get my air compressor and blow out years of old tape oxide, tobacco ashes and other misc dirt. I then begin all the bench work, checking/replacing caps. I made a jig to bench check the various power supplies. Once they are operational. I check the wiring harness, and backplane for any PS issues. And ok and on it goes. It takes months to restore son I can afford to be meticulous like you.
I am so glad to see a person who also slows down, take time and safely!!
from beginning to the end the pace and content is totally absorbing. I personally have no interest in audio equipment but that did nothing to spoil my enjoyment of the video. I love your attention to details that most would never even consider. keep up the fantastic work and looking forward to many more videos in the future.. Karl
+Karl Fell Thanks for the kind word Karl! Many more video's to come :^)
+Karl Fell Bro. That is exactly what I was thinking. I understand very little of what is being said but I couldn't stop watching. Haha
Agreed. I was captivated the entire two hours!
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That was a very good refurbishment. I think a lot of people would have given up and said it was too far gone. You actually not only restored it you made it batter than factory. Nice job.
Thanks Andrew! The Fella that owns it is a great guy, I'm just glad it has a good home.
What an impressive perfectionism combined with explanations which are state of the art even for laymen like me! I'm mainly interested in boatbuilding but your channel Mr Carlson is an outright enrichment for the whole YT community.
Thank You for your kind comment Oskar!
Where did you learn all this? You must have a natural talent for this, you speak very fluidly and are comfortable with electricity. You should do a video covering your history and how you became so talented in this.
It is fascinating to see you work. Everything makes sense. Why is there only one of you out there?! Thanks so much for enlightening us all,
I would love to see you give it back to the customer. If somebody went above and beyond on a machine of mine like you always do, I would be in tears.
Thanks Nicholas!
Another great repair video!! And this time you scared me a little when you "rebuked" the amplifier! I noticed it quit throwing surprises right away. Perhaps you could start all repairs with a finger wag and rebuke. Thanks again for the excellent and thorough repair and circuit protection device.
For a musician to meet a guy like Mr. Carlson is a dream come true. I cant imagine letting anybody else repair my equipment.
2 hours well spent watching this, many thanks Mr Carlson. Great job.
+Rubus Roo Thanks for stopping by! Glad you enjoyed.
One of the smartest guys in TH-cam hands down. And without a doubt my favorite person to watch diagnose radios and amplifiers. Sheer brilliance
I love your systematic procedure and well structured explanations in your videos. I would very much like to see some kind of "trouble shooting manual"-video from you, as you mentioned in the beginning.
+Róbert Valdimarsson I will do that troubleshooting series soon Robert. Thanks for your comment!
You are so right. Alot of people go about both repair and construction in a very obtuse manner. It's almost like they want to make things look super complicated so that they can look very intelligent to people who don't understand what they are doing.
Mr. Carlson, what a fantastic video. Start to finish. It had everything. If there are people that want to learn electronics this is the channel they need to be watching. Also this video really helped me understand what you do for a living. Your website does a good job of that as well, but this is like having a window into your workshop and getting a guided tour. It's a real treat. Keep up the great work! I'm floored. Also you do fantastic work! Beautiful what you did here. I can't imagine your time and services are inexpensive, but I would say you are worth every cent and in reality are probably a steal. You go the extra mile and that's not a common thing. Now I'm like, "what video do I watch next?" Caps in backwards, FT-1000MP repair... ugh, it's a good problem to have. :)
Thanks for your kind words William!
Did yo use a laser printer for the protection board I heard you mention using a heated acid to remove the excess copper, I never heated the acid good idea. If you did use a laser printer on glossy thick card stock, what did you use to get the ink off? I may have missed this part. I noticed how clean job was so I know you didn't use abrasives did you?
Its so easy, this life saving procedure. Just touch all the capacitor connections. If you wake up on the other side of the room, you know that the one you touched was charged. Leave the amp for a month so for the capacitor discharge before you work on it again. :D :D :D
Totally agree William. I'm zactly the same.
why he is just fixing amps why don't he make and designee them he would make so much more money
I'm relatively 'old school' electronics.. (ex Radio Officer) And 40 years after my college and sea time, have got a tad rusty on my valve theory. You Paul Carlson, have taught me more and reminded me more of what I learned than any other reference. Your explanations and language are perfect for this discipline. You are one of my favourite haunts.
I am currently designing my own guitar valve amp, with a sort of hybrid equalisation/filter stage and multiple output amp, giving me 3,15, 30 watt option.
But what a beautiful amp this is. This is very close to my design cabinet, the loping front and control layout is how I envisage my completed design. Shudder to think how much all those trannies cost, if one had to replace them.
LOVE THE CAPACITOR BLOCK MODULE ! Ditto for the 'Soft Start' / overvolt protection circuit !
.
PS.Your videos (and those of Guitologist) have been priceless. Also your tutorials on the lab gear have reawakened parts of my brain, I thought would forever remain asleep. GREAT WORK MATE. But remember we have 240vac line voltage in the UK and 220vac in Europe... So some reference there would be helpful. Otherwise, keep up the fantastic tutorials.
Thanks for your kind comment, and input as well!
A NEW CARLSONS LAB! I saw you posted a comment on an EEVBLOG teardown video a few days ago and it made wonder when youd put another one out. Ive missed the refreshingly intense attention to detail your videos always contain. This was FASCINATING. Thanks!
+Cole Knapek Glad you enjoyed Cole!
Mr. Carlson’s
Your Channel is the BEST of all of the videos that I been watching for the past two years. I was trining to figure out who can restore my Vintage HH Scott LK 150 Amp, LC 21 Preamp and LT 110 Tunner That i own since 1975 and everyone that i asked they told me that they were too busy. I thought that Blueglow Electronics was the best but after watching this video you are on top by making you’re own circuit boards and fixing all of the other things that some one else did, and making it wright for the customer you are worth every penny that you charge.
What a fantastic video! Especially loved the part where you measured the frequency response, absolutely brilliant! You are a master of your craft!
+alex martin Thanks for the kind words Alex!
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Electronics guy for decades here but your videos impress the heck out of me. Thanks much for sharing your knowledge with us. The melding of old and new technology, wow.
+plantopguy5 Great to hear! Glad your enjoying the video's, and thanks for the kind words.
"Listen here amplifier...." "......No more surprises......."
Gave me a good chuckle..
Me too. I still play through this beautiful amplifier often - one of my favourites.
I wish I could give more 'thumbs ups' for this video! What a trove of information Paul gives about tube amplifier design and implementation as it was done in this wonderful old late 1930s Thordarson T20W40 amplifier. He then goes through a step-by-step modification process to bring it up to modern reliability standards so the the owner can take it on the road knowing that it will perform perfectly every time he uses it -- all that without damaging its look, function or old-time esthetics. This is the third time I viewed the entire two hour long video and each time I learned so much more that I didn't quite pick up on or understand before. Paul really packs in the electronics knowledge here and you can't get it anywhere else.
Another outstanding repair and video. The capacitor block just takes the cake. Looking forward to the troubleshooting series. Thank you for sharing all this knowledge!
+pithandmoment Glad your enjoying the video's! Thanks for stopping by.
Hello, Mr. Carlson! Please more TUBE AMP videos or especially best practices for HUM mitigation considering component/transformer selection, star grounding, ground loops, component placement. when shielding is necessary or useful, etc. I am a guitar player that loves tube amplifiers, whom for which, the confluence of those facts, and having no money, has had the consequence of forming me into becoming an amateur technician, and learning all i can get my hands on. Such a rarity are instructional videos that delve into any level of instruction that could surpass any kind of a novice level that your videos have become like gold to me. In fact, they have come to be so useful in my instruction, that the guilt induced by the advantage I have gained thus far has compelled me to donate a few dollars to your Patreon. I shall do more when i can. THANK YOU! I implore all of those who have benefited like I have to please do the same!
You are so gracious in providing to us in your videos, the same level of meticulous care and attention in your videos that you give to your projects, and you, as much as any musician i have ever met, are an ARTIST, except dressed in Wizard's robes. All of your videos, and especially this one, have inspired me through an affirmation of my initial suspicions that the same level of focus, attention to detail and ruthless meticulousness that helped me grow my skills as a musician, would be the same types of methods that would allow me to grow as a technician as well. And it is your professionally clean and robust work habits that i have adopted as my standard.
In this video, your thorough explanation of the addition of the complimentary protection circuits, and your explanation of the role of each component in your design unlocked more understanding for me about circuits than the last 3 books I have read about electronics, combined. Invaluable were the details you included when you had made answer for any potential rebuttals that you considered might come questioning the rational in your designs, and your responses in kind.
Ive written too much. Again, please, more TUBE AMP WIZARDRY! Perhaps conversion of old PA heads, Organ amps, or tube radios into Guitar heads, or a video especially about best HUM mitigation practices in tube amps.
2 minutes into the video and I subscribed !!!! I just love your videos !! This was sooo cool to watch. Any chance of doing more of these tube amp troubleshooting and repair vids? Keep up the good work. I'm telling all my tech / gear head friends about your channel...
+Joe Strabley
Thanks Joe!
I dont want to make your head swell Paul, but you really are the master of electrical engineering
This video is pure gold. I wish to thank you for your meticulous work and amazingly thorough explanations. Sincerely, your new subscriber.
your videos never age. I honestly thought this video was from the last few months, but it's back in 2015. that's crazy.
Elegant soft-start and protection circuit, I can say! Young man, for me you are Arnold Schwartzenegger of electronics! 👏👏👏
I have watched this video numerous times over the years and am just amazed at the simplicity and complexity married together in the soft star over voltage. Also after watching all of your videos I have a feeling that whiteboard was only drawn on once haha. I am wishing that I had someone like you and I was younger to apprentice under
Outstanding job Mr Carlson.
+Bobby Tectalabyss Thanks Bobby!
Superb teaching style Mr. Carlson. Been an educator >25 years, prof at Columbia University and several European universities - and having taught countless lectures - your presentation style got me re-inspired to notch up my teaching and go back to spend some more time in my own electronics lab. Thank you!.
+Admir Hadzic
Thanks for the nice comment Admir! It's great to read that I inspired you.... Comments like this make these video's worth the trouble.
+Mr Carlson's Lab DO YOU TEACH PRIVATE COURSES?
If you were a doctor all of your patients would be healed!
J J , AND.... not only would they be healthy, but would probably live to 125 years of age with no "leakage." LOL
cyberfloater That’s right I think. That you can precent substances to the body that makes the body fight the sickness. I try to keep my body alcaline and not acidic. Cancer loves an acidic body. Some cancer Don’t grow as fast or stops growing in a alcaline body some doctors have proven .
cyberfloater Why is it a great sin to be a alt doctor? Alfred “Dr Sabi” Bowman, Stanislaw Burzynski... I saw parts of a trial with witnesses saying that Dr Burzynski’s treatment were successful. But Wiki starts with this: “The Burzynski Clinic is a controversial clinic offering an unproven cancer treatment.” Not right. Wikipedia should not be biased. Who owns Wikipedia?
Rarely I can handle to watch 2 hr. movie or video from start to finish, but I was nailed at my seat and finished watching your video non stop, thanks for really, really interesting content of this fantastic informative video.
It took 2 minutes to get me to subscribe.
+derbigpr500
Glad your enjoying! Thanks for your comment.
me2
I have absolutely no idea what you are talking about but I watch anyway. Your expertise is incredible, that much I can understand.
I watch these long after they’ve been recorded and they never seem old. That’s a good trick 🙂
what a wonderful video. very thourough and interesting content, your knowledge always impresses me. Hats off!!
Awesome/ clear/ easy - relaxed- “common sense “to “? Confidence understood & unadulterated “
“Usuabld Valuable “-...
“INFOmation”?!....Thankyou, Dj Campbell Jr.
Is it just me, or can anyone else smell this room? Nothing like the smell of scopes and soldering stations early in the morning! Classic equipment there! Go Tektronix! Kudos on the Icom 746 making a cameo appearance! 73 de AK4FM!
Very clear...very detailed....a great tour in trouble shooting......Great narration.....as if a walk through the jungle with an expert guide....thanks...... I'm subscribing.....; )
+William Earney
Thanks William! Glad you enjoyed the video.
+Mr Carlson's Lab This is precisely the reason why I don't stuff cans or do what that other tech did because they do need to vent and I would have used a dual 50uf 500v or a dual 32uf at 500v or even a dual 100uf and then add the 3rd cap somewhere else that is electrically the same point.I realize the cap failed from over voltage but I still believe in being cautious..Excellent video as usual.
Happened on this video by chance and you drew me right in. I have a couple high-end vacuum tube audio components that utilize soft start in the power up and protection circuitry. Thanks for explanation.
I am about to do a total capacitor replacement on a 1965 era shortwave radio and then realign the IF and oscillator circuit. Next come the trimmer caps and tuning coils. I owned this radio from new in my high school years and putting back in service.
I like the way you problem solve, analize repair action and implement corrections. Your attention to detail is the sign of a great engineer.
What a cool old amp and you really did it justice in this video. I liked that you designed protection for it so it should live to play for generations
By the way: Hister-ee-sis :)
+Michael Lloyd LOL, I will practice the word :^) Thanks for the nice comment!
After Mr. Carlson finished restoring it, I told him it would be an heirloom - and it surely will be! What a beautiful and amazing sounding 80 year old amp. I'll enjoy playing it for many years to come!
Just to say thank you Mr Carlson for taking the time to put these video's together, its much appreciated.
+AyFrame Thanks for watching!
That is a beautiful amp. I would love to copy its cabinet and lay out to build a 'close to original' ground up replica of that.
+shortwave It definitely is unique.
Mr. Carlson you never miss anything in your description of the unit or the problem.
Wow, electronic engineer. Complex puzzles. Exceptions to this rule and that rule, and then exceptions to the exceptions..... Man You don't have to worry about dementia (Good memory). You got me Soldered from start to finish on this video. Very descriptive, concise and comprehensive. Some people charge money for your knowledge. Subscribe.
+Mcbeth2pl
Thanks for your kind comment!
I grew up playing with tube stuff back in the 1960s. Your warnings are just common sense to me but well justified. I've suffered more than a few ouch moments that could have been much worse.
Interesting circuit there for voltage limiting !
Those two big 'scopes on the upper right sure brought back some good memories. Those plug in modules gave them so much more capability than many believed when they first came out. It saved having to have so many different scopes around doing different things. I miss those days but that was decades ago for me.
372 likes and no dislikes. Great job!
I am a computer programmer. I really enjoy how you plan for even low-probability problems by adding zeners and caps in critical points if something unexpected happens. In programming, the biggest problem is not making the program do what you want, it is making sure IT DOES NOTHING ELSE!! In software, this can be really difficult, since the number of unexpected inputs in a really complex program can be well nigh infinite, hence the success of hacking. You are a REAL PRO.
YOU have so perfect experience and an excelent job god bless you
You lost me at Hello! Almost the same as in the movie but not quite :). I've been watching for about 5 hours now, can't stop. No kidding, you're a freaking Genius! I have very little understanding of what you say, but I have picked up a few things. The knowledge and understanding you have; the command you have of the lingo; and the way you demonstrate everything, I'm blown away. You should be working for NASA. Your obvious love for electronics and your expertise is one thing. However in stead of being arrogant you are very humble, and even kind. When you could have trashed the tech that first "got into" the Thordarson T20W40 tube amplifier, you handled it very professionally and as a gentleman. The fact that you so willingly spend a huge amount of time doing this for us, at no cost speaks volumes as to the kind of person you are. Actually, you could probably RUN NASA, but I think your true calling is indeed that of a teacher.
I've been trying to find help with a little 5 Watt Bugera amp that I messed up and that's how I came across your videos. Wow, what intelligence and passion. I'll keep coming back just to try to learn a speck of what you know. Thank you and be well.
+J. Mack
Thanks for your very kind comment J.Mack! Glad you enjoyed the video.
As always great video Paul! Can't wait for the next one! Take care
+TRXBench Thanks Peter! Holidays are over, now we want video's! LOL! hope your holidays were great!
+Mr Carlson's Lab LOL yeah videos are already in production and coming soon. Holidays were great.
Great! I look forward to your next video.
Great to know there's people out there that still understand this stuff. I don't - yet still enjoyed the video.
+Will Rich
Thanks for the kind words Rich.
You are one smart young fella. Like your videos greatly. :-)
+David Okanagan Thanks for the kind words David! More video's like this to come.
I’m transfixed every time I watch your videos, Mr. Carlson. My hat goes off to you!
Who the hell gave this vid a thumbs down ?!?
Very jealous ppl
Some very jealous people. This guy is truly amazing!!
+Mirror rorriM
Thanks for the kind words!
Mr. Carlson's like:dislike ratio is incredible, I am almost positive it's the highest of any channel I've seen, and across all his videos too. I still find it strange that even a few people can bring themselves to click the dislike button.
You know I come here for several reason's. First, because after watching so many of your videos and talking back and forth via the comment section, I have come to think of you as a friend, one who I would happily shake hands with, even with this virus scare. Second, I come here to be entertained, because your video's are that and more, they keep my mind active, even though I am loosing the ability to concentrate because of age and debility. Third, I come to learn. I have been very interested in the magic in the moving electron ever since the incident I alluded to below, having the electrons coursing through a young healthy heart and soul does something to the mind that draws it to conquer that witch it fears the greatest, and that plug in the wall became a fascination and a fear at the same time. That said, I can learn more from one of your videos, about the operation of circuits, how to build them for my own purposes and the reasoning behind the operation of them then I can by reading all the books in the library dealing with electronics. So thank you for keeping an aging mind active, for your friendship over the web, and for being such a wonderful teacher. May you be safe from that horror that now inhabits our every thought across the planet, and join me on the other side of the pandemic as still my greatest teacher. May God Bless. KE0JBL
In the UK it's 'hiss-ter-REE-sis'.
+Silas Fatchett
LOL thanks!
The musician who owns this amplifier is so very lucky to have you as a electrical engineering resource. It is hard to believe you know so much about electronics. Very informational, and entertaining for the layman. It's only my guess, but I am going to say your services much be in such great demand. I can't imagine anyone who needed something electrical fixed, wanting anyone else but you to work on their equipment.
"I'm Bad at the one word, 'Hysteresis' - perhaps the only thing Mr. Carlson is not good at is pronouncing that word. :P
hiss-tur-EEEE-siss
David Mckee , And as a teacher, I never said a WORD! LOL Some words refuse to be pronounced correctly, possibly because so few people know what they mean. Paul uses the word knowledgeably because he may not SAY all the things he knows but knows what they mean!
I restore vintage electronics (mostly tube amps and Tube radios). Your understanding of the electronics is amazing considering your young age. I love your videos and set through them beginning to end. They are very educational and I have picked up some great tips from you. Also, love your lab!
Thanks Chris, glad your enjoying!
Wow, You're so clever ! Huh ?. : P
Mr. Carlson, I only recently stumbled across your channel. I love watching your restoration of old radios, but this amp project caught my eye because I play in a band. I was excited to see your soft-start circuit power up, but I was not expecting a full test of your protection circuit, and I got a little nervous as you dialed up the line voltage past 120V. When the B+ got to 500V and the protection cut it off, I actually stood up and cheered! Thank you for an excellent and informative video.
This is not the first time I've watched this video. As someone that is self-learning electronics, the portion of the content you devoted to the soft start circuit is incredibly instructional. My interests are in audio amps and linear power supplies, so your channel is gold to me.
Nice to listen to someone who knows what he is talking about. Very good.
That cap bank arrangement you have devised gave me a warm fuzzy feeling, like everything is right with the world. Beautiful job 👍
Thanks!
WOW in your opening, you have explained to me what probably happened to me some 60 years ago. We had just moved from "the home place" which was built in 1908 and had no electric power to a nearby farm that dad rented, while placing our old place in the Soil Bank. We attended a farm auction right after the move and dad bought us a beautiful Airline floor model radio, my what care that machine had received, that farm wife must have dusted it daily and waxed it regularly, it still glowed like it was in the showroom. That radio had the cylinder tuner indicator with all the names of the radio stations and shortwave cites, as well as police channels on it. Being about 8 at the time, I wanted to hear those stations. So when mom and dad were out in the barn doing chores and my sisters were off collecting eggs and such, I began to play with that radio! The push-button that I though should bring me the joy of dragnet, or spies from Russia was stuck, or so I figured as when I pushed it, nothing happened. I had watched dad for years repairing our old battery pack tube set on the home place so I knew you started wiggling tubes to figure out what was wrong, so I pulled the set out and began wiggling tubes, and reaching around to find that magic button. Well I hit on something magic, I saw blue arch's and stars were all around me. I physically flew backward against that farm house wall so hard that it took weeks for the bruises to subside. I suddenly had a new respect but deepening interest in the power of electricity. I still have that to this very day, perhaps because of that shocking experience. When I told dad about it, it resulted in a trip to the wood shed where he kept an old razor strop hanging, that strop was put to use against my bare ass more times then I could count, and this, I believe even re-enforced my strong interest in electricity and the work it does for man. Bet I hit the top of one of those tube.
I cannot believe this extremely high quality EE video is available to us for free! I watched the whole thing twice, so great thanks!!!
+Tennisplayer21Kim
Your welcome Kim!
That old amp is truly beautiful when all together. Great craftsmanship and design. Now that you have added a modern dose of craftsmanship and care it will continue to deliver its beauty to the world. Like an old car restored and being driven daily. Thanks for sharing.
always nice to see someone who takes pride in their work.
+irateyourvideo2
That I do! Thanks!
Excellent work been working on big tube amps since I was 14 , I'm 63 now , very nice to have a good exclamation of work done and how detective work on the units repair history Harry .
+Harry Conover
Thanks Harry!
Like the way you have respectfully worked with the design and the past repairs as a point in time. The design is what it is, then you put your own science and desgin.
Nice work
Thanks Michael!
I'd love to see you design a stereo amplifier to the best of your ability because you are so incredibly talented
Waves through the quantum (electron) field... The radio is full of moving parts.... It amazes me to no end...thanks so much, prof Carlson
I love how you take every facet into consideration when you modify and enhance these devices. Every time I think of a "what if", it seems like you're reading my mind and answer it directly! Your attention to detail is simply unworldly!! Keep up the great work!
+Shawn Walsh
Thanks for the very kind words Shawn!
I'm just getting started and have a rudimentary understanding of the components and how they function in a circuit. I watched the entire video knowing in the future this information will impact me. What I do know is that in your solutions and design is that I have seen where art and science intersect. Thank you!
+Harold Hayes III
Thanks for your kind words Harold. Glad your enjoying the video's.
Checking resistance from the rectifier filiment points to ground.. Might damage the DVM if there is a charged filter capacitor in there somewhere. Might be best to touch a jumper to chassis to the filiment pins first before checking that resistance...still a great piece of kit... I've been tinkering with tube gear most of my life.. I've learned a few lessons the "hard" way, over the years... Major thanks to my late father for my interest in all this.
Excellent service tutorial! The amount of detail that you dive into has to be greatly appreciated. There is no other channel in TH-cam that gives this much information for any single product. Really appreciate your effort and dedication when making these videos. Keep going.
Thanks for your kind words Sangeeth!
My knowledge of electronics is limited. However, I've always enjoyed your videos, even though most of it is over my head. What I do know, you really go the extra mile to provide the best service possible.