I cannot get enough of your videos -- just the right tempo, and very thorough explanation -- you must have been a professor somewhere -- I taught math for 15+ years and know how tempting it is to just go ahead full speed -- you explain things thoroughly and also anticipate the questions that would come up...and Rusty is still deciphering the milk-bones,...Hang in there Rusty -- you'll figure it out..Thanks for these good videos..
You're quite welcome, Bill. I too was a math teacher for 17 years, and probably developed my video approach as a result of what I found to be a successful teaching strategy.
Uncle Doug, you are an awesome teacher! Sometimes I have to go over your material several times to get it, but you explain things very well. I have run into a hand full of people in my life that I consider true teachers, you are right at the top of the list.I have been intrigued by capacitors since I began learning how guitar amps work. But I admit, some of it has been pretty much over my head. This series on caps has really opened my eyes to what's actually happening during operation. Thank you! You really are awesome man...
You're welcome, KV, and thanks for your extremely nice comments. Supportive words such as yours really make our YT channel a worthwhile and rewarding experience for both Rusty and me.
Best mini-series on capacitors I've seen. 3D-animations? Fancy visuals? Nope, that's not necessary! All it needs is someone with profound knowledge and an unsurpassed talent to explain! ... oh, and 2 trustworthy sidekicks like Rusty and Jack. Gotta love the pet-interludes :D Great work, thanks muchly!
I'm probably repeating myself, but your videos are really great. That goes for all three parts in this capacitor series, and all other of you videos I've seen so far. I don't know a better teacher in this field. You explain not just "how" but also "why" in an excellent way. I have got so much use of the knowledge you share. Thanks, Uncle Doug!
Uncle Doug, I was schooled on tube and associated electronics while being trained as an electronic tech to work on the HAWK Air Defense Missile System while in the Army in 1966. With my recent interest in tube amps I was frustrated by my failure to remember after 50+ years. Lol. Watching your instruction has taken me back. Thanks for helping me to begin my journey back. You are a top notch teacher and much appreciated.
Hey Uncle Doug, Ich simply wanted to extend my huge thanks to you for keeping up your quest in explaining the functions of amplifiers to the simple-minded like myself. I recently finished my third amplifier build, a complete scratch build of an Orange Super Bass from the late 70ies, after starting out with a Marshall 18Watt Kit and converting an old Siemens Radio into a Vox style Amp with two 6BQ5 tubes, a 12AX7 and an EF86. All that would not have been possibly, without your work, so tahnks a lot and keep 'em conversions and scratch builds coming! Greetings from Germany, Phil
After watching this series, I then went back thru them again to take notes. I write really small, I took 10 pages of notes. Now I see why you didnt recommend a book on this subject.. You are "The Book..." lol So much knowledge you hold and I'm blessed to be able to learn from you. Thank you Uncle Doug. I will become a Patron member and show you much support as this virus stuff winds down. Now off to the Resistors 101 class you have.. stay safe and God Bless.
I really like your approach to teaching, factual and clear explanations how things happen within components.........the speed at which you move forward and length of lesson is spot on. Those of you from the "Electronics Generation" have an amazing ability to explain things in High detail, yet simply..........please please please keep doing this sort of thing, or the true skill of the Electronics Tech will be lost in this generation.........the age of the IC has taken away the basic principals of how things work in the "Engine Room" of electronics. I am going to refer new players to both your and Elpaso's channels for learning aids.......Bringing your wonderful old dog and cat into these is a brilliant way to wake people up and refresh them into paying attention.....plus its great fun......you are a master educator , and I thank you for taking the time to pass your knowledge on.
Thanks so much for your very nice comments, HE. Rusty, Jack, and I really appreciate the fact that you appreciate what we do. In return, we wish you the very best in all your endeavors.
These videos are extraordinary. I have a much more fundamental understanding now than previously. I always had a bit of a mental block with electronics because nobody was able to explain the fundamentals as well as you. I hope you understand how valuable all these videos are. Thanks.
I've been working with electronics for years, and could never fully grasp a lot of the concepts I "learned" in EP courses-- until your videos. Thank you so much for these. I got my interest in electronics from modifying my (brother's) guitar, but ran into some speed bumps while taking traditional EP courses in the Air Force. I think the key for me is your practical approach in explaining amps, etc. Keep it up!
Congratulations mr. Doug. I am a teacher of electricity and electronics and, like you, I lived the age of tubes and I love this world, and I make this world my weekend hobby. I often refer to your videos, and I watch your videos for inspiration and find ways to teach my students in a simpler and more efficient way. Thank you for sharing your knowledge.
Hi, uncle Doug and helpers.! Your comment about charging up a cap. And giving it to a pest.!, reminded me of a time many years ago when I was an electrician in a factory. An office member who had an easy job not doing much, would wonder into the electrical shop to waste a bit of time., he would mess about and pick things up to look at.we charged a capacitor up that had two screw terminals on the top with a discharge resistor across which we had disconnected and left on the bench. Sure enough in he walked picking things up getting in the way, suddenly there was a Yelp! And dropping said capacitor he disappeared without a word. He didn't come in very much after that ...cheers from England. Hugs to assistant rusty. Love all your easy to watch informative videos on valve amps. my old 1963 vox AC30. Is in For service as we speak. Cheers Rob.
Greetings, Rob, and thanks for your very nice comments. I guess the joke might be on us if our intended victim touched each of the cap leads with a separate hand and was electrocuted.....but until that fateful day (and prosecution), the old "charged cap" trick definitely rids the work environment of unwanted pests :)
I definitely have to send your videos to my college professors, so they can learn how to explain complex subjects easily and passionate the way you do! I just love your videos, full of information + a very easy english to listen and understand. Greetings from Brazil!
I'm very flattered that you feel that way, AM. Thanks. Like you, throughout my formal education, I had some really good teachers......and some really lousy ones.
Well I'm speechless. You gave all ampoholics a chance to build their own tube amp. You and Rusty made a remarkable job. You play with electrons just the way you play with nature's instincts. Thanks UD!
Finally, I have read so many books on this subject and just cannot get my around it, but now with your excellent teaching I finally understand Capacitors, Thank you so much
Thank you for all of your time, knowledge, and willingness to teach us the things you know, Uncle Doug! Your videos are the best teachings i have found on TH-cam... Easy to grasp the concepts, yet still very deep. Bless you sir!
Hello Mr. Uncle Doug. I find your video's to be very informative and well explained. I'm new to these things, being a musician/guitarteacher all my life (55 now). I finally get to understand the working of tube amps which reduces costs on simple maintenance. The cat and dog intermissions always bring a smile on my face :-) Greetings from the Netherlands.
Hi Doug from wales UK, I enjoyed the series so much I was sorry when it ended. I can only Agree with every one else and say thanks for taking the time to teach us all . Really great series .Thanks again. Oh and thanks to Rusty and Jack too.
Uncloe Doug, thank you so much for your videos. I'm starting my journey in electronics , so far I build small guitar preamp (with lots of satisfactions) and I watch your videos one by one discovering it all. Your approach to explain is not too shallow nor too deep , just perfect. Thanks !
As always, the very best series on capacitors I've seen. Even if, like in my case, you are a seasoned tube jock, the clear and simple view of a subject, can provide a higher level of understanding which will help in design and repair of the many circuits in a guitar tube amp and other audio circuits. You are the master of teaching through sharing your vast knowledge of electronics. Thank you so much for these wonderful videos, which will be preserved "for all mankind". I know I am long in the tooth, but some times, when you have some thing to say you just have to say it. Thankz
Uncle Doug deserves a medal of honor! Always professional in depth of things explained.🎖 Also I stuck into some thing called vintage "dual can capacitors". A high voltage elektrolytic can cap with multi capicity tags in in case I got dry out one in circuit I want to replace this thing. The last thing I want to do is ask some stupid question. I doubt in what way it opperates in the circuit. The diagram shows... power transformer(secundair 320VAC>rectifier>Capacitor 16+16+16uF(MFD) 400VDC (outher can is negative) The 3. 16uF tags are connected with resistors and each tag has a different lead for function. I wondering is this thing parallel or series inside constructed? I ordered 3 separated axial capacitors with equal vallue (3x 16uf/400VDC) with the purpose of replacement. So series or parallel is to essential to choose. Hope Uncle knows because he knows best. I can show diagram if required 😊👍🏼greetings
The three capacitors are separate within the can.....just like the three separate capacitors you bought. They are not wired in series or in parallel. Each one connects a different point in the power supply to ground......just like it shows in the schematic.
Uncle Doug Thank you so much Uncle Doug allways much appreciated. I think I was thinking too complicated. When the 3 positive lugs of that old can cap connect with each other with a 2.2k resistor from lug A(feeding VDC)>B followed by 4.7k to lug B>C. I was a bit confused.. i meassure a doubler in capacitance and its old, its dangerous, certainly working with high voltage capacitor. Better ask before harm or die 😊 👍🏼thanks and greetings from Netherlands
Thanks Doug - the 'fog' is now beginning to clear (especially on electrolytics !)...I once diagnosed a fault on a computer clock circuit (1974 vintage) without really understanding why. It was a little tantalum electrolytic that was wrongly polarised. The power station only had one working clock board and seven non-working. A little investigation revealed all non-working ones were also reverse polarised - I had a small promotion as a result !
Hi Uncle Doug, Rusty & Jack, A most excellent series with great explanations, graphic's and appearances by Rusty & Jack. Seems Rusty is teaching new tricks to Jack. You are a really good teacher, Thankyou. I hope all is good. Take care, C.
I really enjoyed this series on capacitors. I'm an old electronics buff but was in IT for quite a while during my career, so I've enjoyed the refresher. But I mostly enjoyed your videos of Jack and Rusty. Loved your comments especially the CAT scan one. 🤣
Excellent. Enjoyable. When I was 13 I thought I was extra dumb because this was so hard for me to understand. Now 55 years later, I know for certain that I am dumb but it's comforting to know I understand. I was an electron in my former life and now have a love affair with physics. Thank you Rusty, Jack and your human.
Hi Doug. I know this is old (so am I ), but I had to chuckle when I heard your cap charging story. Many years ago when I was taking electronics in the Air Force, they had plugin boards to teach building of various types of circuits with plugable components to accomplish each. There was always some smartass who would come around and mess with what you were doing, so I did the same with the DC power supply charging a few caps and leaving them on the bench. After a bit of fondling my stuff the smartass would inevitably come across one of the charged caps and the instructor would inquire about the noise usually a bit of profanity, and the smartass would depart the area. That brought back some old memories.
It's a great way to get rid of annoying visitors, HT. It would be unfortunate if a victim had a heart attack......but I guess you could just put the cap back in the drawer and call 911 ;)
I have learned a great deal from these three videos. Finally I understand why caps are used in tone circuits. Very many thanks. I really enjoyed the biscuit test too. Thanks very much.
Love your videos.....I'm actually writing down the notes on your capacitor videos cause there so well explained and informative. I'm slowly learning electronics to help me restore my tape decks and amplifiers. Thank you
I’m in love with your explanations! You are one of the greatest teacher I have herd ever! Thank you very much. Just a couple of yours videos and I will be ready to start with my first tub amp! Just keep going, stay safe! With all my best regards, Ainis from Latvia
Thanks for the excellent Video series on capacitor applications in audio circuits Uncle Doug. It is informative; comprehensive; concise; and optimally organized !! You are a great teacher! And obviously an accomplished animal trainer. Jack has an uncanny ability to detect bad caps !!
You're welcome, Donald, and thanks for your very nice comments. Jack and Rusty come by their prodigious skills by heredity rather than education. They were both born to sniff :)
Muchas gracias por toda la data, tus videos son sumamente claros! estoy viendolos uno tras otro. Incluso siendo en ingles se entienden perfectamente, saludos desde Argentina!!
De nada. Estamos contentos de que disfrutar de nuestros videos. Aunque somos de diferentes países, compartimos un interés común en la electrónica de tubo. Los mejores deseos de Rusty, Jack y tío Doug.
For whatever reason, I guess it is just "my time" to watch all these videos. I have not fooled much with electronics in many years. Some of this information was taught to me years ago. However, I am at a point where I can really absorb it. REALLY appreciate this stuff!
P.S. Jack and Rusty are a wonderful addition to what some would say is a deep and scary subject. You are so lucky to have them both and they are lucky to have you as a life companion! Thankz
Great video series! Will there be some other series like this in future? So informative and clear and your drawing skills are so good! Great job, as always. Honor to you and Rusty, Uncle Doug! =)
Thanks so much, GW. We're going to take a little rest for a few days and then start looking around for new topics. Best wishes to you from all the gang at Chez Rusty.
Uncle Doug, i really admire and appreciate the way you're teaching. I learn a lot and gain infinite knowledge from you. My dream someday to see you. From philippines with love...
Hi Doug. Absolutely brilliant video. I always struggled with the capacitor a dark art ,its almost magic . I am studying for my next amateur radio exams ,the Intermediate licence UK. There is a lot on capacitor and filters and your video is a great help. Anyway thanks a lot still do not understand all of it but almost. Time for a beer! With regards David UK
Hey Uncle Doug I have been watching your videos over the past six months and have enjoyed every minute. I have seen most of them and using the information in my attempt to learn how to do some amp servicing for myself. I studied MET in college and had some EET classes as well and did well in those classes so I do have some background albeit long long ago. I am amazed at your knowledge of so many different areas and not only knowledge but apparent expertise. You are truly gifted sir. My question. I noticed you have recently stopped posting videos. I am saddened by this event and hope that you are okay. With the assumption that you are doing well, I am asking if you intend to produce anymore videos? I am hoping that you are just busy and that my message finds you in good health. Regardless of your intentions of producing videos or not, I sure wish you my best. My Best to you
Thanks so much for your concern, Scott. We've been sidetracked by some new hobbies and fully intend to continue making videos......hopefully in the reasonably near future. Until then, our best to you and yours.
Thanks for the great tutorial on Caps. I am a big fan of you,Rusty and Jack and really enjoy the amp restoration vids. I am gathering parts for a fender champ build . I will be watching a lot more of your videos for tips.
I've been binge watching your vids since I came across them a couple weeks ago. This is amazing stuff. I have an electrical engineering degree, but I've been stuck in the world of software for the last 20 years. Your videos have rekindled a love of circuits that I'd almost forgotten about. And your delivery and wit are just icing on the cake. I just finished this series because I was hoping to find out how to determine which type of cap to use based off of a schematic. When building an amp off of schematics where should one use polar vs non-polar caps. Orange drop vs electrolytic? Do you have a video that I might have missed (or not yet gotten to) that covers all of this?
Welcome, HW. Thanks so much. Electrolytics are used exclusively for power supply filtration (usually 10 to 50uf @ 450 to 500V) and as cathode bypass caps (usually 25 to 50uf @ 50V). All the remaining (tone and signal) caps are non-polar, i.e. Orange Drop, polypropylene, etc.
I am a new subscriber to your channel. I love your humor with Rusty and Jack. It really keeps the deep technology you are teaching in context with reality. I love the info and am getting a great deal of education about those "simple" tube amps we love!
excellent once again! I loved the use of caps to get rid of unwanted visitors as well as the discussion on electrolytic caps! oh, and of course its good to see Jack coming out of his shell!
Hi uncle doug, glad to see you back ive enjoyed all your video's i have learned so much more watching them. Sad to hear about rusty .Regards Bob parker England
Excellent vid again Doug. Very thorough explanation of reforming electrolytic caps and the balance of phasing. Thanks as always and tell Rusty and Jack that Carl sez hey.
Thanks for this clear explanation in the capacitor series! I think in a short time you'll end up brightning up all the black spots in amplifier circuits on this channel. Maybe it should feature a playlist(s) for more advanced proceeding through on this topic where you organize your videos, more like an online textbook or something.
You're welcome, Andras. A playlist is available for subscribers, but it it organized chronologically rather than by topic. I will keep your suggestion in mind. Thanks :)
I find these to the point explanations nice and soothing, though I knew most of it already. Nice to hear them in the context of a tube amplifier. About the cat: there is a Dutch saying "Omwille van de smeer likt de kat de kandeleer" or "Because of the grease the cat licks the candelabre" so I think the waxy nature of the condensators is the attraction.
We're happy to hear that you enjoy our videos, Roeland, and enjoyed your rather unusual saying. You may be right.....perhaps the wax has an appealing odor.
Your channel has inspired me to try and build my first tube amp from scratch. Im a web developer who has been rewiring guitars and fx boxes for years but never an amp. with the dangers in mind, building a 15watt tube amp could be so much fun for me. Any suggestions for a model/schematic? I realize something like a 5e3 is better for beginners but id like to gave something that uses el84s (2x) and results in 15w.
Greetings, Luke. It's great to hear that you are ready to build your first amp. My preference would be the 5E3 Deluxe, but if you are more inclined toward a DE amp using EL84's then perhaps a kit like this would be of interest: www.ebay.com/itm/Classic-British-18W-18Watt-Chassis-DIY-EL84-Amplifier-Tube-Guitar-Amp-Kit-/252385890210?hash=item3ac35f0fa2:g:avQAAOxyrUZRyqIs If you want to build completely from scratch, then download the schematic of a DE EL84 amp you like, make up a parts list, and order the components from Antique Electronic Supply. You will probably have to fabricate your own chassis, however, if you go the scratch-built route. Good luck.
Great video. Do you have a series on which type of capacitor to use in different areas of a tube amp. For instance, where is it appropriate to use or not use a silver mica, a ceramic, an orange drop. It would be a helpful (pt 4 perhaps) video to explain that to us. I am currently rebuilding an HH Scott 299C and they have quite a few inferior ceramics including a few in the early stages of audio path. So again this would in my opinion be a great addition to this series, explaining what where and why. Thanks..
From my experience, M-100, the type, brand, or cost of capacitor has little effect on tone. I have removed (inferior) ceramic caps and installed relatively expensive caps.....with absolutely no noticeable effect on tone. I suggest that everyone try their own experiments in this area, but meanwhile I stand by my conviction that money spent on boutique caps is money wasted. You would be far better off taking the difference in cost and applying it where it would have obvious beneficial effect: speaker and possibly tubes.
Thanks for the reply Uncle Doug. I mainly use orange drop 716 series in audio path. What I was really curious about is the appropriate use of Ceramic/Silver Mica for bypass and where in a circuit not to replace a ceramic with a silver mica.. the Following is a quote from a friend that has a lot more experience with theory than I do. Just wondering if you would comment on it. quote = Remember that subbing micas for ceramics isn't always a good idea. Read up on dielectric materials and their optimal uses in audio. Micas always replace micas. Ceramics need to stay ceramics for screen bypass positions. Signal path ceramics swap to film/foil. Tone circuitry ceramics can go to mica or film. Film caps swapped only with film, and never to ceramic.
You're welcome, M-100. As previously stated, I obey none of these rules. There are probably excellent theoretical reasons for them, but from my own experience, the effects are neither audible nor worth the trouble. Like you, I tend to favor polyester and polypropylene caps such as Sprague's and use them liberally in all positions except where electrolytics are required. To me, correct value and good quality is all that really matters.
Hey Uncle Doug, sure do miss you and rusty. Hope all is well with you and look forward to seeing some new videos in the future. I've learned more from your channel than almost every other source combined and still reference it frequently. Thanks for taking the time and sharing all your knowledge with us
You're welcome, WD. Jack and I are doing fine, but Rusty passed away several months ago. We hope to be able to produce some more videos in the near future. Thanks for your very nice comments.
Uncle Doug Sorry to hear about rusty. He was a good helper although sometimes less than enthusiastic but how can you blame a dog as smart as him. R.I.P. Rusty
Hi Uncle Doug, what are your go to brand/series of capacitors to use in preamp and poweramp sections of an amp. I'm looking at doing a cap job on a bass amp and would appreciate your recommendation. BTW keep up the excellent videos, I'm always eager to watch. Thanks.
I use good quality but economically priced capacitors from Antique Electronic Supply, Declan, such as Illinois or Mallory metalized polypropylene tubular resistors. I also like Sprague Orangedrop caps for a vintage look.
Uncle Doug, Thanks for these great videos. Questions about testing and reconditioning electrolytic capacitors using the "variac method". I am working with power supply caps in the 10 to 100 MuF range. Can you apply an AC 60 Hz voltage to recondition them, or must you use a DC (or pulsed DC from a rectifier) to do this? (I think the answer is DC only.) I tried using a gradually increasing AC voltage using a dimmer switch. I put the test capacitor in parallel with a lightbulb and brought the voltage up with the dimmer switch. Fortunately I put a 2 Amp fuse in my circuit. I found that I quickly blew the fuse with a 100 MuF cap. Using the equation for Xc when C= 100 MuF and f=60 Hz gives Xc=26 Ohms. That means that I would blow my 2 Amp fuse at 52 volts. V= i Xc = 2 x 26 = 52 Volts. It seems like it blew at an even lower voltage! Anyway, I quickly realized that I must be doing something wrong here. Can I recondition my caps using an amp circuit? If I have an amp with a solid state rectifier, can I plug the amp in to the dimmer switch with no tubes in it and then bring the voltage up slowly with the dimmer switch and thereby gradually apply a pulsed DC signal to my filter caps for the B+ power supply? This is probably too many questions, but perhaps you could make a video about this. Thanks!
You can only re-form electrolytics using gradually-increasing-voltage DC, Cosmo. They are a dead short for AC......hence your experiences with it. Nowadays, with high quality capacitors readily available at very reasonable cost, it makes better sense to simply replace the caps.
@@UncleDoug Thanks for the confirmation Uncle Doug! I love your videos. I played with tube stereo amps with a friend in college. Both of us became engineers (mechanical and bio, not electrical). My dear stereo friend is dead and gone and now another old friend has got me interested in tube guitar amps, as he is a great guitar player who has just discovered the magic of tubes. I am a tinkerer and he has brought me an old Alamo Fury to play with. Despite the advantages of buying new caps (which I will likely do, eventually) I am still interested in the reconditioning process. If I have an amp with a solid state rectifier, can I recondition the caps right there in the amp by bringing the voltage up slowly by plugging the amp into a variac (or dimmer switch)? Is it better to do this with or without the tubes in? Could I build my own reconditioner using a dimmer switch, power transformer, and a solid state rectifier? If yes, could you suggest a circuit layout for this? THANKS SO MUCH FOR YOUR FAST REPLY! You are currently my favorite "Professor" of the University of TH-cam!
Back in 77 when I was separating from my second enlistment in the US Army, I took training in an auto mechanic course. When it came time to deal with the distributer, coil and such we began to play with condensers (just another name for large capacitors in the spark area of a car) We had a tester/charger for them. It was a common thing to charge them up and call another student's name, then toss the charge condenser. Man that discharge was quite a deal and most of those who caught the little silver condensor dance like it was 1966 and they had just taken a hit of LSD, while acid rock played in the background.
Hi Uncle Doug, that’s for the great explanation. One question that I hope is no too silly: if a capacitor blocks DC in a circuit where it is functioning as a coupling capacitor, is the DC voltage that is “felt” on circuit after the capacitor “effectively sent to ground” via a resister? (Just checking if I have the correct understanding). If my question does not make sense, feel free to just tell me to rewatch the series. That is a perfectly fine response. I do not expect you to explain the error in my thinking in your response. Thanks!
Your question makes very good sense, Zoltan. A small portion of the blocked DC is absorbed and stored within the capacitor. The rest passes through the plate resistor to ground.
It appears that the voltage lags the current in capacitors in the AC circuit and as it relates to the oscillator you show in the schematic and your own drawings. Is it the current that is being sent back a head of phase or the voltage lagging the current that is being sent back to the other grid of the 12AX7? I hope the questions aren't so ridiculous. Thanks for answering my questions up to now no matter how silly they may be.
The current leads the voltage in capacitive circuits, so the phase is negative. To me, it's because you first apply current to a capacitor and then the voltage builds. Perhaps this diagram will clarify the relationship: hyperphysics.phy-astr.gsu.edu/hbase/electric/phase.html
As usual, an absolutely brilliant series of simple yet effective explanations. The only thing I'm left wondering is who are the 16 jackasses that disliked it.....
Love these video's and the supporting cast. Have have a question about old un used filter caps. I bought a large amount of spragues about 10 years ago and never used them. I am starting to rebuild some of the amps in my collection and wonder if these caps can be used, refreshed or thrown away?? thanks, john
They're probably just fine. If you have a DC power supply, bring them up to operating voltage slowly (i.e. over several minutes). If not, and you use them in an amp, use a Variac to bring them up slowly. If you don't have either, then build a Current Limiter and use it with the amps they are used in. I predict no problems at all.
Thanks, that is great news. I am re watching most of your video's in preparation for some rebuilds......I think I am starting to make a transition from a mechanic to one who understands why it works.......You have a great style of explanation in a clear way. thanks!!
I’m a little confused about filter capacitors. If caps block DC voltage, How then do they smooth a voltage to fundamentally make it more DC? I understand the concept that they charge and discharge slowly, thereby providing smoothing, but this seems at odds with the concept of blocking DC. What am I missing? Is it dependent on the values of the caps in relation to the 60 Hz signal? Thanks as always for your videos and assistance!
The DC does not go through the filter caps, it goes past them. You can see this when you look at a schematic. As the DC leaves the rectifier with some ripple, it passes by each filter cap, which charge during the ripple peak and discharge during the trough, "filling in" the trough so that the ripple is smoothed to its peak height.
@@UncleDoug I was thinking of how easily the annoying visitor can complete the circuit with the different package types ;) I've started collecting parts for my my first build. Got the valves (that what we call tubes downunder) and an OT and choke. About to order all the smaller stuff - I'm going with Mallory 150 series caps for coupling and tone circuit. I've watched these older videos of yours several times. Your work has given me the inspiration and confidence to do it!!! Thanks bloke!!
So to properly understand the dielectric being only on the anode means the capacitor has a preferred polarity? With regards to the voltage rating i assume the electrolyte can pass charges so doesn't it effectively short the isolation and hence voltage rating. That is, its like bringing two high voltage cables closer . Re the caps leaking : it is a massive issue with circuit break downs , i would have thought they would have a much better construction by now since the 70s..
Yes, it appears that the polarity is based on which plate has the Aluminum Oxide coating. Current doesn't pass through the electrolyte, its ions dissociate to create an opposing charge on the plates. Yes, DC leakage is a big issue, especially in coupling and filter caps.
Uncle Doug, am i right in thinking when AC is fed into one side of the cap and AC then flows from the other side it has not physically jumped the gap but induction has taken place across the gap a bit like a transformer but without ant voltage change, and like a transformer it does not work when DC is applied?
Exactly, George. Neither AC or DC can actually "cross the gap" between the two plates. AC stimulates the creation of an equal charge on the distal plate, so it "appears" to have crossed over, while DC simply charges the plates with no current exiting from the distal plate.
I cannot get enough of your videos -- just the right tempo, and very thorough explanation -- you must have been a professor somewhere -- I taught math for 15+ years and know how tempting it is to just go ahead full speed -- you explain things thoroughly and also anticipate the questions that would come up...and Rusty is still deciphering the milk-bones,...Hang in there Rusty -- you'll figure it out..Thanks for these good videos..
You're quite welcome, Bill. I too was a math teacher for 17 years, and probably developed my video approach as a result of what I found to be a successful teaching strategy.
Uncle Doug, you are an awesome teacher! Sometimes I have to go over your material several times to get it, but you explain things very well. I have run into a hand full of people in my life that I consider true teachers, you are right at the top of the list.I have been intrigued by capacitors since I began learning how guitar amps work. But I admit, some of it has been pretty much over my head. This series on caps has really opened my eyes to what's actually happening during operation. Thank you! You really are awesome man...
You're welcome, KV, and thanks for your extremely nice comments. Supportive words such as yours really make our YT channel a worthwhile and rewarding experience for both Rusty and me.
KrackerVision I agree man :)
I had trouble with the actual operation of capacitors ( at least in electronic circuits ) for a long long time. Finally getting it cleared up.
Your videos age well. Knowledge and wisdom never get old. Thanks for teaching 🙏
You're quite welcome, Raphy :)
Best mini-series on capacitors I've seen. 3D-animations? Fancy visuals? Nope, that's not necessary! All it needs is someone with profound knowledge and an unsurpassed talent to explain! ... oh, and 2 trustworthy sidekicks like Rusty and Jack. Gotta love the pet-interludes :D Great work, thanks muchly!
Wow, thanks so much for your very nice comments, KL. Rusty, Jack, and I really appreciate them and are glad you enjoyed our video :)
I'm probably repeating myself, but your videos are really great. That goes for all three parts in this capacitor series, and all other of you videos I've seen so far.
I don't know a better teacher in this field. You explain not just "how" but also "why" in an excellent way. I have got so much use of the knowledge you share. Thanks, Uncle Doug!
Thanks so much for your very nice comments, Bengt. We're glad you enjoy the videos :)
Uncle Doug, I was schooled on tube and associated electronics while being trained as an electronic tech to work on the HAWK Air Defense Missile System while in the Army in 1966. With my recent interest in tube amps I was frustrated by my failure to remember after 50+ years. Lol. Watching your instruction has taken me back. Thanks for helping me to begin my journey back. You are a top notch teacher and much appreciated.
You're welcome, Roger. Best wishes for continued success with your new hobby :)
Hey Uncle Doug,
Ich simply wanted to extend my huge thanks to you for keeping up your quest in explaining the functions of amplifiers to the simple-minded like myself.
I recently finished my third amplifier build, a complete scratch build of an Orange Super Bass from the late 70ies, after starting out with a Marshall 18Watt Kit and converting an old Siemens Radio into a Vox style Amp with two 6BQ5 tubes, a 12AX7 and an EF86.
All that would not have been possibly, without your work, so tahnks a lot and keep 'em conversions and scratch builds coming!
Greetings from Germany,
Phil
You're quite welcome, Jan. It's great to hear that our videos helped you with your successful projects. Best of luck on all your future builds :)
After watching this series, I then went back thru them again to take notes. I write really small, I took 10 pages of notes. Now I see why you didnt recommend a book on this subject.. You are "The Book..." lol
So much knowledge you hold and I'm blessed to be able to learn from you. Thank you Uncle Doug. I will become a Patron member and show you much support as this virus stuff winds down. Now off to the Resistors 101 class you have.. stay safe and God Bless.
I really like your approach to teaching, factual and clear explanations how things happen within components.........the speed at which you move forward and length of lesson is spot on.
Those of you from the "Electronics Generation" have an amazing ability to explain things in High detail, yet simply..........please please please keep doing this sort of thing, or the true skill of the Electronics Tech will be lost in this generation.........the age of the IC has taken away the basic principals of how things work in the "Engine Room" of electronics.
I am going to refer new players to both your and Elpaso's channels for learning aids.......Bringing your wonderful old dog and cat into these is a brilliant way to wake people up and refresh them into paying attention.....plus its great fun......you are a master educator , and I thank you for taking the time to pass your knowledge on.
Thanks so much for your very nice comments, HE. Rusty, Jack, and I really appreciate the fact that you appreciate what we do. In return, we wish you the very best in all your endeavors.
These videos are extraordinary. I have a much more fundamental understanding now than previously. I always had a bit of a mental block with electronics because nobody was able to explain the fundamentals as well as you. I hope you understand how valuable all these videos are. Thanks.
You're welcome, Ariel. Thanks so much !!!
I've been working with electronics for years, and could never fully grasp a lot of the concepts I "learned" in EP courses-- until your videos. Thank you so much for these. I got my interest in electronics from modifying my (brother's) guitar, but ran into some speed bumps while taking traditional EP courses in the Air Force. I think the key for me is your practical approach in explaining amps, etc. Keep it up!
Thanks so much, CTS. We will :)
This channel is pure gold for guitar amp maniacs.
Thanks, K :)
Congratulations mr. Doug. I am a teacher of electricity and electronics and, like you, I lived the age of tubes and I love this world, and I make this world my weekend hobby. I often refer to your videos, and I watch your videos for inspiration and find ways to teach my students in a simpler and more efficient way. Thank you for sharing your knowledge.
You're welcome, Oswaldo. I am flattered that you would hold my work and methods in high esteem.
Hi, uncle Doug and helpers.! Your comment about charging up a cap. And giving it to a pest.!, reminded me of a time many years ago when I was an electrician in a factory. An office member who had an easy job not doing much, would wonder into the electrical shop to waste a bit of time., he would mess about and pick things up to look at.we charged a capacitor up that had two screw terminals on the top with a discharge resistor across which we had disconnected and left on the bench. Sure enough in he walked picking things up getting in the way, suddenly there was a Yelp! And dropping said capacitor he disappeared without a word. He didn't come in very much after that ...cheers from England. Hugs to assistant rusty. Love all your easy to watch informative videos on valve amps. my old 1963 vox AC30. Is in For service as we speak. Cheers Rob.
Greetings, Rob, and thanks for your very nice comments. I guess the joke might be on us if our intended victim touched each of the cap leads with a separate hand and was electrocuted.....but until that fateful day (and prosecution), the old "charged cap" trick definitely rids the work environment of unwanted pests :)
I definitely have to send your videos to my college professors, so they can learn how to explain complex subjects easily and passionate the way you do! I just love your videos, full of information + a very easy english to listen and understand. Greetings from Brazil!
I'm very flattered that you feel that way, AM. Thanks. Like you, throughout my formal education, I had some really good teachers......and some really lousy ones.
Thank you for taking the time to make these videos. Cat scan was a first for me.
I hope you enjoyed them, RL :)
Well I'm speechless. You gave all ampoholics a chance to build their own tube amp. You and Rusty made a remarkable job. You play with electrons just the way you play with nature's instincts. Thanks UD!
You're welcome, John, and thanks for your very nice comments :) We're glad you found the videos helpful.
Finally, I have read so many books on this subject and just cannot get my around it, but now with your excellent teaching I finally understand Capacitors, Thank you so much
That's good news, Neil. You're quite welcome.
Your videos are some of the best educational videos I’ve ever seen. You are a master educator. Thank you!
Wow.....thanks so much, Ronnie. We really appreciate it :)
Excellent teaching Uncle Doug! This takes me back to the late 1980’s when I got my associate’s degree in electronics. 😊
Thanks, MK :) Glad it was helpful.
Thank you for all of your time, knowledge, and willingness to teach us the things you know, Uncle Doug! Your videos are the best teachings i have found on TH-cam... Easy to grasp the concepts, yet still very deep. Bless you sir!
Thanks so much, Shawn. It's great to hear that the videos are clear and informative.
Finally! Somebody explains what haunts me for a very long time! That is about "blocking DC". Only one image says it all, to me at least.
I'm glad the video was helpful, Real.
My dog Rommel and I take notes, I love these classes, Thank you
Rommel looks like a very bright student, Tim. Admit it......do you cheat off his tests?? ;)
Great video as usual !! You are a wonderful teacher !! The best on the internet, period. Thank you and keep the videos coming !!
You're welcome, MS, and thanks so much for your very nice comments :)
Hello Mr. Uncle Doug. I find your video's to be very informative and well explained. I'm new to these things, being a musician/guitarteacher all my life (55 now). I finally get to understand the working of tube amps which reduces costs on simple maintenance. The cat and dog intermissions always bring a smile on my face :-) Greetings from the Netherlands.
Greetings to you, Jos, and thanks for your nice comments. Rusty, Jack, and I send you our warmest regards from Texas, USA.
Hi Doug from wales UK, I enjoyed the series so much I was sorry when it ended. I can only Agree with every one else and say thanks for taking the time to teach us all . Really great series .Thanks again. Oh and thanks to Rusty and Jack too.
You're quite welcome, Steve. It's great to hear that the component series was helpful and appreciated.
Uncloe Doug, thank you so much for your videos. I'm starting my journey in electronics , so far I build small guitar preamp (with lots of satisfactions) and I watch your videos one by one discovering it all. Your approach to explain is not too shallow nor too deep , just perfect. Thanks !
You're welcome :) Best of luck on your journey.
As always, the very best series on capacitors I've seen. Even if, like in my case, you are a seasoned tube jock, the clear and simple view of a subject, can provide a higher level of understanding which will help in design and repair of the many circuits in a guitar tube amp and other audio circuits. You are the master of teaching through sharing your vast knowledge of electronics. Thank you so much for these wonderful videos, which will be preserved "for all mankind". I know I am long in the tooth, but some times, when you have some thing to say you just have to say it. Thankz
You're welcome, ATL. It's great to hear that you enjoyed the video series. We really appreciate your very nice comments.
I must Parrot 🦜 one of your viewers posts. " This is what TH-cam is for. " Thanks for your content.
You're quite welcome, Joseph. Thanks !!
Uncle Doug deserves a medal of honor! Always professional in depth of things explained.🎖
Also I stuck into some thing called vintage "dual can capacitors". A high voltage elektrolytic can cap with multi capicity tags in in case I got dry out one in circuit I want to replace this thing.
The last thing I want to do is ask some stupid question.
I doubt in what way it opperates in the circuit. The diagram shows... power transformer(secundair 320VAC>rectifier>Capacitor 16+16+16uF(MFD) 400VDC (outher can is negative)
The 3. 16uF tags are connected with resistors and each tag has a different lead for function.
I wondering is this thing parallel or series inside constructed? I ordered 3 separated axial capacitors with equal vallue (3x 16uf/400VDC) with the purpose of replacement. So series or parallel is to essential to choose. Hope Uncle knows because he knows best. I can show diagram if required 😊👍🏼greetings
The three capacitors are separate within the can.....just like the three separate capacitors you bought. They are not wired in series or in parallel. Each one connects a different point in the power supply to ground......just like it shows in the schematic.
Uncle Doug Thank you so much Uncle Doug allways much appreciated.
I think I was thinking too complicated. When the 3 positive lugs of that old can cap connect with each other with a 2.2k resistor from lug A(feeding VDC)>B followed by 4.7k to lug B>C. I was a bit confused.. i meassure a doubler in capacitance and its old, its dangerous, certainly working with high voltage capacitor. Better ask before harm or die 😊 👍🏼thanks and greetings from Netherlands
Thanks Doug - the 'fog' is now beginning to clear (especially on electrolytics !)...I once diagnosed a fault on a computer clock circuit (1974 vintage) without really understanding why. It was a little tantalum electrolytic that was wrongly polarised. The power station only had one working clock board and seven non-working. A little investigation revealed all non-working ones were also reverse polarised - I had a small promotion as a result !
Good diagnosis, Dave.
Hi Uncle Doug, Rusty & Jack, A most excellent series with great explanations, graphic's and appearances by Rusty & Jack. Seems Rusty is teaching new tricks to Jack. You are a really good teacher, Thankyou. I hope all is good. Take care, C.
You're welcome, Cass, and thanks for your nice comments. All is great here at Chez Rusty.....we hope it's the same with you :)
I really enjoyed this series on capacitors. I'm an old electronics buff but was in IT for quite a while during my career, so I've enjoyed the refresher. But I mostly enjoyed your videos of Jack and Rusty. Loved your comments especially the CAT scan one. 🤣
Glad you enjoyed it, Stewart. It's great to hear from you :)
Thanks uncle doug (and RIP Rusty). Great tutorials as I try and understand the circuits for a first home-build. I'm taking notes!
You're welcome, Shalman :)
A book written by this gent should be made.
Thanks, David. Meanwhile, a free and universally accessible electronic record of all our videos exists on line.
Excellent. Enjoyable. When I was 13 I thought I was extra dumb because this was so hard for me to understand. Now 55 years later, I know for certain that I am dumb but it's comforting to know I understand. I was an electron in my former life and now have a love affair with physics. Thank you Rusty, Jack and your human.
Thanks so much, Larry. Best of luck with your continued pursuit of knowledge.
Hi Doug. I know this is old (so am I ), but I had to chuckle when I heard your cap charging story. Many years ago when I was taking electronics in the Air Force, they had plugin boards to teach building of various types of circuits with plugable components to accomplish each. There was always some smartass who would come around and mess with what you were doing, so I did the same with the DC power supply charging a few caps and leaving them on the bench. After a bit of fondling my stuff the smartass would inevitably come across one of the charged caps and the instructor would inquire about the noise usually a bit of profanity, and the smartass would depart the area. That brought back some old memories.
It's a great way to get rid of annoying visitors, HT. It would be unfortunate if a victim had a heart attack......but I guess you could just put the cap back in the drawer and call 911 ;)
I have learned a great deal from these three videos. Finally I understand why caps are used in tone circuits. Very many thanks. I really enjoyed the biscuit test too. Thanks very much.
You're welcome, Mike.
Love your videos.....I'm actually writing down the notes on your capacitor videos cause there so well explained and informative. I'm slowly learning electronics to help me restore my tape decks and amplifiers. Thank you
You're welcome, Horst. Best of luck with your training program.
Very informative + very interesting + great fun to watch. A very big thank you! Looking forward to start seeing 'Resistors, Part 1'...
You're welcome, Patrick. I'm glad you enjoyed the video :)
I’m in love with your explanations! You are one of the greatest teacher I have herd ever! Thank you very much. Just a couple of yours videos and I will be ready to start with my first tub amp! Just keep going, stay safe! With all my best regards, Ainis from Latvia
Wow.....thanks so much, Ainis. It's great to hear that you are enjoying our videos :)
Thanks for the excellent Video series on capacitor applications in audio circuits Uncle Doug. It is informative; comprehensive; concise; and optimally organized !! You are a great teacher! And obviously an accomplished animal trainer. Jack has an uncanny ability to detect bad caps !!
You're welcome, Donald, and thanks for your very nice comments. Jack and Rusty come by their prodigious skills by heredity rather than education. They were both born to sniff :)
Muchas gracias por toda la data, tus videos son sumamente claros! estoy viendolos uno tras otro. Incluso siendo en ingles se entienden perfectamente, saludos desde Argentina!!
De nada. Estamos contentos de que disfrutar de nuestros videos. Aunque somos de diferentes países, compartimos un interés común en la electrónica de tubo. Los mejores deseos de Rusty, Jack y tío Doug.
For whatever reason, I guess it is just "my time" to watch all these videos. I have not fooled much with electronics in many years. Some of this information was taught to me years ago. However, I am at a point where I can really absorb it. REALLY appreciate this stuff!
P.S. Jack and Rusty are a wonderful addition to what some would say is a deep and scary subject. You are so lucky to have them both and they are lucky to have you as a life companion! Thankz
You're welcome, ATL. The three of us have formed a mutual admiration society :)
Great video series! Will there be some other series like this in future? So informative and clear and your drawing skills are so good! Great job, as always. Honor to you and Rusty, Uncle Doug! =)
Thanks so much, GW. We're going to take a little rest for a few days and then start looking around for new topics. Best wishes to you from all the gang at Chez Rusty.
Uncle Doug--
Long after I have committed all of your tutorials to memory, I'll still come back for Jack the Cat, and Rusty the Wonder Dog.
They'll still be here for you, Stephen ;)
Man that`s so good ...watching Jack sniff out those Capacitors . I was in hysterics it made my day . Best Regards Stu
Glad you enjoyed it, Stu :)
Uncle Doug, i really admire and appreciate the way you're teaching. I learn a lot and gain infinite knowledge from you. My dream someday to see you. From philippines with love...
Thanks so much, MR. I guess it could happen some day :)
Great video Doug. Many thanks.
Hi Doug.
Absolutely brilliant video.
I always struggled with the capacitor a dark art ,its almost magic .
I am studying for my next amateur radio exams ,the Intermediate licence UK. There is a lot on capacitor and filters and your video is a great help.
Anyway thanks a lot still do not understand all of it but almost.
Time for a beer!
With regards
David UK
You're welcome, David. I wish Rusty and I were there to join you for the beer :)
Thanks again.
Doug. Rusty and Jack
for another great Vid
Thanks Colin
You're welcome, Colin :)
Hey Uncle Doug
I have been watching your videos over the past six months and have enjoyed every minute. I have seen most of them and using the information in my attempt to learn how to do some amp servicing for myself.
I studied MET in college and had some EET classes as well and did well in those classes so I do have some background albeit long long ago.
I am amazed at your knowledge of so many different areas and not only knowledge but apparent expertise. You are truly gifted sir.
My question. I noticed you have recently stopped posting videos. I am saddened by this event and hope that you are okay. With the assumption that you are doing well, I am asking if you intend to produce anymore videos?
I am hoping that you are just busy and that my message finds you in good health. Regardless of your intentions of producing videos or not, I sure wish you my best.
My Best to you
Thanks so much for your concern, Scott. We've been sidetracked by some new hobbies and fully intend to continue making videos......hopefully in the reasonably near future. Until then, our best to you and yours.
More great info. I need to take snapshots of your “cheat sheets” and put them on the walls of my workshop!
Feel free to duplicate anything that helps you, FC. That's what we're here for.
Thanks for the great tutorial on Caps. I am a big fan of you,Rusty and Jack and really enjoy the amp restoration vids. I am gathering parts for a fender champ build . I will be watching a lot more of your videos for tips.
You're welcome, Rab. Thanks for the nice comments :)
Best of luck with your Champ project.
I've been binge watching your vids since I came across them a couple weeks ago. This is amazing stuff. I have an electrical engineering degree, but I've been stuck in the world of software for the last 20 years. Your videos have rekindled a love of circuits that I'd almost forgotten about. And your delivery and wit are just icing on the cake.
I just finished this series because I was hoping to find out how to determine which type of cap to use based off of a schematic. When building an amp off of schematics where should one use polar vs non-polar caps. Orange drop vs electrolytic? Do you have a video that I might have missed (or not yet gotten to) that covers all of this?
Welcome, HW. Thanks so much. Electrolytics are used exclusively for power supply filtration (usually 10 to 50uf @ 450 to 500V) and as cathode bypass caps (usually 25 to 50uf @ 50V). All the remaining (tone and signal) caps are non-polar, i.e. Orange Drop, polypropylene, etc.
I am a new subscriber to your channel. I love your humor with Rusty and Jack. It really keeps the deep technology you are teaching in context with reality. I love the info and am getting a great deal of education about those "simple" tube amps we love!
Thanks for all your nice comments, Lee, and for subscribing to our channel :)
excellent once again! I loved the use of caps to get rid of unwanted visitors as well as the discussion on electrolytic caps! oh, and of course its good to see Jack coming out of his shell!
Thanks, Dave. Yes, capacitors have many applications.....not all of them involving electronics :)
Another great educational video. Thanks I'm trying to learn all I can.
You're welcome, Z55. We hope the videos assist your pursuit of knowledge.
Hi Uncle Doug. Thank you for posting all these great learning and fun videos.
All my best.
Bobby
You're welcome, Bobby :)
A cap sniffer 🤣🤣🤣 man, i think i just fall in love with your videos ❤😂
Thanks, Federico :)
Thank you for your help.
Good luck to you and Rusty.
You're welcome, Andrew. Thanks for your good wishes :)
Great stuff Uncle Doug, really enjoyed this series. You have a lot of excellent material on your channel. Thank you!
You're welcome, Shy. Thanks !!
Hi uncle doug, glad to see you back ive enjoyed all your video's i have learned so much more watching them. Sad to hear about rusty .Regards Bob parker England
Excellent vid again Doug. Very thorough explanation of reforming electrolytic caps and the balance of phasing. Thanks as always and tell Rusty and Jack that Carl sez hey.
You're welcome, Carl. Rusty, Jack, and I always enjoy hearing from you :)
Thanks for this clear explanation in the capacitor series! I think in a short time you'll end up brightning up all the black spots in amplifier circuits on this channel. Maybe it should feature a playlist(s) for more advanced proceeding through on this topic where you organize your videos, more like an online textbook or something.
You're welcome, Andras. A playlist is available for subscribers, but it it organized chronologically rather than by topic. I will keep your suggestion in mind. Thanks :)
I find these to the point explanations nice and soothing, though I knew most of it already. Nice to hear them in the context of a tube amplifier. About the cat: there is a Dutch saying "Omwille van de smeer likt de kat de kandeleer" or "Because of the grease the cat licks the candelabre" so I think the waxy nature of the condensators is the attraction.
We're happy to hear that you enjoy our videos, Roeland, and enjoyed your rather unusual saying. You may be right.....perhaps the wax has an appealing odor.
Your channel has inspired me to try and build my first tube amp from scratch. Im a web developer who has been rewiring guitars and fx boxes for years but never an amp. with the dangers in mind, building a 15watt tube amp could be so much fun for me. Any suggestions for a model/schematic? I realize something like a 5e3 is better for beginners but id like to gave something that uses el84s (2x) and results in 15w.
Greetings, Luke. It's great to hear that you are ready to build your first amp. My preference would be the 5E3 Deluxe, but if you are more inclined toward a DE amp using EL84's then perhaps a kit like this would be of interest: www.ebay.com/itm/Classic-British-18W-18Watt-Chassis-DIY-EL84-Amplifier-Tube-Guitar-Amp-Kit-/252385890210?hash=item3ac35f0fa2:g:avQAAOxyrUZRyqIs If you want to build completely from scratch, then download the schematic of a DE EL84 amp you like, make up a parts list, and order the components from Antique Electronic Supply. You will probably have to fabricate your own chassis, however, if you go the scratch-built route. Good luck.
thanks!
Hands down this is the funniest show on TH-cam!!........ oh yeah and informative as well
Thanks, BO.....we try to do both :)
Great video. Do you have a series on which type of capacitor to use in different areas of a tube amp. For instance, where is it appropriate to use or not use a silver mica, a ceramic, an orange drop. It would be a helpful (pt 4 perhaps) video to explain that to us. I am currently rebuilding an HH Scott 299C and they have quite a few inferior ceramics including a few in the early stages of audio path. So again this would in my opinion be a great addition to this series, explaining what where and why. Thanks..
From my experience, M-100, the type, brand, or cost of capacitor has little effect on tone. I have removed (inferior) ceramic caps and installed relatively expensive caps.....with absolutely no noticeable effect on tone. I suggest that everyone try their own experiments in this area, but meanwhile I stand by my conviction that money spent on boutique caps is money wasted. You would be far better off taking the difference in cost and applying it where it would have obvious beneficial effect: speaker and possibly tubes.
Thanks for the reply Uncle Doug. I mainly use orange drop 716 series in audio path. What I was really curious about is the appropriate use of Ceramic/Silver Mica for bypass and where in a circuit not to replace a ceramic with a silver mica.. the Following is a quote from a friend that has a lot more experience with theory than I do. Just wondering if you would comment on it.
quote = Remember that subbing micas for ceramics isn't always a good idea. Read up on dielectric materials and their optimal uses in audio. Micas always replace micas. Ceramics need to stay ceramics for screen bypass positions. Signal path ceramics swap to film/foil. Tone circuitry ceramics can go to mica or film. Film caps swapped only with film, and never to ceramic.
You're welcome, M-100. As previously stated, I obey none of these rules. There are probably excellent theoretical reasons for them, but from my own experience, the effects are neither audible nor worth the trouble. Like you, I tend to favor polyester and polypropylene caps such as Sprague's and use them liberally in all positions except where electrolytics are required. To me, correct value and good quality is all that really matters.
Hey Uncle Doug, sure do miss you and rusty. Hope all is well with you and look forward to seeing some new videos in the future. I've learned more from your channel than almost every other source combined and still reference it frequently. Thanks for taking the time and sharing all your knowledge with us
You're welcome, WD. Jack and I are doing fine, but Rusty passed away several months ago. We hope to be able to produce some more videos in the near future. Thanks for your very nice comments.
Uncle Doug Sorry to hear about rusty. He was a good helper although sometimes less than enthusiastic but how can you blame a dog as smart as him. R.I.P. Rusty
Thanks, WD. We really miss him.
Hi Uncle Doug, what are your go to brand/series of capacitors to use in preamp and poweramp sections of an amp. I'm looking at doing a cap job on a bass amp and would appreciate your recommendation. BTW keep up the excellent videos, I'm always eager to watch. Thanks.
I use good quality but economically priced capacitors from Antique Electronic Supply, Declan, such as Illinois or Mallory metalized polypropylene tubular resistors. I also like Sprague Orangedrop caps for a vintage look.
Thanks! Gerat video series. You're able to explain hard things easy!
You're welcome, Murrat, and thanks for your very nice comments :)
Uncle Doug, Thanks for these great videos. Questions about testing and reconditioning electrolytic capacitors using the "variac method". I am working with power supply caps in the 10 to 100 MuF range. Can you apply an AC 60 Hz voltage to recondition them, or must you use a DC (or pulsed DC from a rectifier) to do this? (I think the answer is DC only.) I tried using a gradually increasing AC voltage using a dimmer switch. I put the test capacitor in parallel with a lightbulb and brought the voltage up with the dimmer switch. Fortunately I put a 2 Amp fuse in my circuit. I found that I quickly blew the fuse with a 100 MuF cap. Using the equation for Xc when C= 100 MuF and f=60 Hz gives Xc=26 Ohms. That means that I would blow my 2 Amp fuse at 52 volts. V= i Xc = 2 x 26 = 52 Volts. It seems like it blew at an even lower voltage! Anyway, I quickly realized that I must be doing something wrong here. Can I recondition my caps using an amp circuit? If I have an amp with a solid state rectifier, can I plug the amp in to the dimmer switch with no tubes in it and then bring the voltage up slowly with the dimmer switch and thereby gradually apply a pulsed DC signal to my filter caps for the B+ power supply? This is probably too many questions, but perhaps you could make a video about this.
Thanks!
You can only re-form electrolytics using gradually-increasing-voltage DC, Cosmo. They are a dead short for AC......hence your experiences with it. Nowadays, with high quality capacitors readily available at very reasonable cost, it makes better sense to simply replace the caps.
@@UncleDoug Thanks for the confirmation Uncle Doug! I love your videos. I played with tube stereo amps with a friend in college. Both of us became engineers (mechanical and bio, not electrical). My dear stereo friend is dead and gone and now another old friend has got me interested in tube guitar amps, as he is a great guitar player who has just discovered the magic of tubes. I am a tinkerer and he has brought me an old Alamo Fury to play with. Despite the advantages of buying new caps (which I will likely do, eventually) I am still interested in the reconditioning process. If I have an amp with a solid state rectifier, can I recondition the caps right there in the amp by bringing the voltage up slowly by plugging the amp into a variac (or dimmer switch)? Is it better to do this with or without the tubes in? Could I build my own reconditioner using a dimmer switch, power transformer, and a solid state rectifier? If yes, could you suggest a circuit layout for this? THANKS SO MUCH FOR YOUR FAST REPLY! You are currently my favorite "Professor" of the University of TH-cam!
Back in 77 when I was separating from my second enlistment in the US Army, I took training in an auto mechanic course. When it came time to deal with the distributer, coil and such we began to play with condensers (just another name for large capacitors in the spark area of a car) We had a tester/charger for them. It was a common thing to charge them up and call another student's name, then toss the charge condenser. Man that discharge was quite a deal and most of those who caught the little silver condensor dance like it was 1966 and they had just taken a hit of LSD, while acid rock played in the background.
It's a great trick, Jerry. Jack and I use it to rid the workshop of unwanted visitors.
I like your method of removing unwanted visitors from your workshop. I may have to try it myself someday. lol
It works well, Riloh, but be sure they don't have a pacemaker or heart problems.
When it comes to this, it would probably be wise if I simply live vicariously through you and your expertise! I did laugh though!
Hi Uncle Doug, that’s for the great explanation. One question that I hope is no too silly: if a capacitor blocks DC in a circuit where it is functioning as a coupling capacitor, is the DC voltage that is “felt” on circuit after the capacitor “effectively sent to ground” via a resister? (Just checking if I have the correct understanding).
If my question does not make sense, feel free to just tell me to rewatch the series. That is a perfectly fine response. I do not expect you to explain the error in my thinking in your response. Thanks!
Your question makes very good sense, Zoltan. A small portion of the blocked DC is absorbed and stored within the capacitor. The rest passes through the plate resistor to ground.
Thank you! And thank so much for all of these excellent learning videos.
@@zoltannemeth8864 You're welcome, Zoltan.
Hi Doug,, Thank you for the great video series on Capacitors,,, Very interesting how Tremolos Work..
You're welcome, Terence.....glad you liked it.
Very interesting tutorial, I learned a lot!.Thank you
You're welcome, Rob.
It appears that the voltage lags the current in capacitors in the AC circuit and as it relates to the oscillator you show in the schematic and your own drawings. Is it the current that is being sent back a head of phase or the voltage lagging the current that is being sent back to the other grid of the 12AX7? I hope the questions aren't so ridiculous. Thanks for answering my questions up to now no matter how silly they may be.
The current leads the voltage in capacitive circuits, so the phase is negative. To me, it's because you first apply current to a capacitor and then the voltage builds. Perhaps this diagram will clarify the relationship: hyperphysics.phy-astr.gsu.edu/hbase/electric/phase.html
As usual, an absolutely brilliant series of simple yet effective explanations. The only thing I'm left wondering is who are the 16 jackasses that disliked it.....
Ignore them, Bill. They are simply drooling misfits who are protesting their mother's refusal to change their soggy, saggy diaper.
hope you're doing great Uncle Doug! missing your videos! cheers!
We're doing fine, Hadi. Thanks for your concern :)
So THATS what that was all about! Sorry Uncle Doug ,I didn’t realize my questions were so annoying! Geez...😏☺️
If you're speaking of the charged capacitor, William, it teaches a valuable lesson ;)
Uncle Doug Well it makes sense NOW,yeah! 👍
Love these video's and the supporting cast. Have have a question about old un used filter caps. I bought a large amount of spragues about 10 years ago and never used them. I am starting to rebuild some of the amps in my collection and wonder if these caps can be used, refreshed or thrown away?? thanks, john
They're probably just fine. If you have a DC power supply, bring them up to operating voltage slowly (i.e. over several minutes). If not, and you use them in an amp, use a Variac to bring them up slowly. If you don't have either, then build a Current Limiter and use it with the amps they are used in. I predict no problems at all.
Thanks, that is great news. I am re watching most of your video's in preparation for some rebuilds......I think I am starting to make a transition from a mechanic to one who understands why it works.......You have a great style of explanation in a clear way. thanks!!
You're welcome, John. We're glad the videos are helpful. Best of luck with your projects.
I’m a little confused about filter capacitors. If caps block DC voltage, How then do they smooth a voltage to fundamentally make it more DC? I understand the concept that they charge and discharge slowly, thereby providing smoothing, but this seems at odds with the concept of blocking DC. What am I missing? Is it dependent on the values of the caps in relation to the 60 Hz signal? Thanks as always for your videos and assistance!
The DC does not go through the filter caps, it goes past them. You can see this when you look at a schematic. As the DC leaves the rectifier with some ripple, it passes by each filter cap, which charge during the ripple peak and discharge during the trough, "filling in" the trough so that the ripple is smoothed to its peak height.
Yes, that make sense. Thanks!
Jack performs a purr-fect cat scan! Go Jack!!
He did indeed :) Thanks, SL.
Doug, do you recommend axial or radial high voltage capacitors for removing ripple from annoying visitors?
I only use axial caps, Vinny. Radials are for PCB's.
@@UncleDoug I was thinking of how easily the annoying visitor can complete the circuit with the different package types ;)
I've started collecting parts for my my first build. Got the valves (that what we call tubes downunder) and an OT and choke. About to order all the smaller stuff - I'm going with Mallory 150 series caps for coupling and tone circuit.
I've watched these older videos of yours several times.
Your work has given me the inspiration and confidence to do it!!!
Thanks bloke!!
Great video again
Thanks :)
You Sir, are awesome!
Thanks so much, B :)
Excellent as always
Thanks, Joe :)
So to properly understand the dielectric being only on the anode means the capacitor has a preferred polarity? With regards to the voltage rating i assume the electrolyte can pass charges so doesn't it effectively short the isolation and hence voltage rating. That is, its like bringing two high voltage cables closer . Re the caps leaking : it is a massive issue with circuit break downs , i would have thought they would have a much better construction by now since the 70s..
Yes, it appears that the polarity is based on which plate has the Aluminum Oxide coating. Current doesn't pass through the electrolyte, its ions dissociate to create an opposing charge on the plates. Yes, DC leakage is a big issue, especially in coupling and filter caps.
Very good Unk!
Thanks, T :)
Just what l needed thanks
Glad to hear it, Rafael.
Very helpful!
Glad to hear it, Ezra :)
Uncle Doug, if you publish a book about tube amp, I will definitely buy one. Thank you!
You're welcome, Mr. K. We appreciate your nice comment :)
Thanks for the new videos. Missed you.
You're welcome, Cherry. It's good to be back :)
Adam West Batman, thanks for your great explanations!
You're welcome, Robin :)
Uncle Doug, am i right in thinking when AC is fed into one side of the cap and AC then flows from the other side it has not physically jumped the gap but induction has taken place across the gap a bit like a transformer but without ant voltage change, and like a transformer it does not work when DC is applied?
Exactly, George. Neither AC or DC can actually "cross the gap" between the two plates. AC stimulates the creation of an equal charge on the distal plate, so it "appears" to have crossed over, while DC simply charges the plates with no current exiting from the distal plate.
Do you have a tutorial on transistors? how they work the different kinds and applications?Thank you
No, I don't Rob. I stick purely with vintage tube circuits and equipment.
Thanks for doing this, great series!
You're welcome, CM :)