Tube Amplifier Tone Stacks: Part 1

[@parachuteman4]

I have to say, out of all the KZbin videos I've ever watched, you are the absolute best teacher I've ever seen

[@UncleDoug]

Wow, thanks so much :)

[@fieldofweeds]

I really like these videos too. It’s wonderful to finally understand how these things work-and my dad used to build ham radios from scratch..

[@loganme]

Just decided to start learning about how tube amps work and can't believe how amazing these videos are. Also, Rusty rules.

[@UncleDoug]

Thanks, Logan. We're glad you enjoy them.

[@JeremiahL]

Im a mechanical engineer. I took E-science in college,.. I got a B in the class, but it was just an endurance test, and I kind of put all of the math in a compressed ball of knowledge that I would discard as soon as the situation allowed... Fast forward 25 years... My hobbies have once again drug me into deep waters.... I dont know why, but I have to understand how all of this works,... Needless to say, but this explanation is so practical and consumable that I just can't stop watching these videos.... I wish there was a way to assign a value to people that were willing and able to spend the effort to present an otherwise difficult to understand topic in practical terms. Its as if someone handed me an exaplaination free of charge, and thanked me for accepting,,, Im very greatfull....

[@UncleDoug]

We appreciate your very kind comments, Jeremiah, and are glad that our videos have been helpful :)

[@epicrapton]

thank you, Uncle. I wish I had this kind of teacher in the university 10 yrs ago.

[@UncleDoug]

Epic Crapton You're welcome, Epic (Rusty loves your screen name). We're glad the video was helpful :)

[@davey4697]

Great name Epic!

[@MLX1401]

The amount of pleasure when you type "passive tone control uncledoug" into that tube search box and find out there's not only one, but two (at least) videos covering the subject. Ahhh.....

[@UncleDoug]

Thanks, ML. We try to cover all the bases :)

[@johndogwater]

These are FANTASTIC! Everyone should watch these, and Rusty is just the icing on the cake. Dogs just move anything onto the next level. Thanks for making these, you are providing a valuable public service.

[@UncleDoug]

+johndogwater You're welcome, John.....glad you enjoy the videos :)

[@Zemiltube]

The best explanation I've seen of what a capacitor does to audio 11:35 and how it works as a filter. So clear at last!!! Thanks you're an awesome teacher and communicator. 👏👏👏

[@UncleDoug]

Thanks, Z. Glad it was helpful.

[@Nobody92421]

10 thumbs down? Must be from amp techs and builders... Sharing and demystifying the sacred arcane knowledge of tone. Best channel on KZbin!!!

[@UncleDoug]

Thanks, TJ. I like to think that all ten disapprovals come from one slobbering idiot with 10 different accounts :)

[@atconditions]

thanks for leaving out the maths and the formulas to make it able to get a basic understanding to begin with.

[@UncleDoug]

You're welcome, AT.

[@shyammohabir8283]

Building and repairing tube amps seems to be a lost art ... Thanks for promoting and teaching us this craft!

[@UncleDoug]

You're welcome, Sammy :)

[@zackakai5173]

There's a surprising lack of material on the internet going in depth about how amp/pedal circuitry works on an electronics level. These are by far the best videos on the subject I've found. EDIT: Oh and also there are dogs, which makes literally anything better.

[@UncleDoug]

Thanks so much, Zack. Glad you enjoy our vids....and pets.

[@jean-pierremarinalonzo3204]

Rusty is my Hero for ever ! Thank's for all the knowledge you share. From France Jean-pierre.

[@UncleDoug]

You're quite welcome, JP. Our best to you all.

[@bobbarcus8310]

Your the best thanks so much for your time to teach us

[@UncleDoug]

Bob Barcus Thanks so much, Bob :)

[@FreddysFrets]

Hi Uncle Doug, So many light bulbs went off in my head watrching this video. I've been tinkering with tube amps for a while but there where areas that I did not really understand that well. The way you explain things is brilliant....for the first time I really get it.WOW! Thank you very kindly sir! Subscribed.

[@UncleDoug]

FreddysFrets You're quite welcome, Fred, and welcome aboard the UD & Rusty Channel. Thanks for watching and subscribing :)

[@5000rgb]

I'm really enjoying you videos, Uncle Doug. I first watched them just to see a little amp repair and learn a bit but these are so much more educational than I expected. You manage to turn every repair into an educational opportunity yet I never feel overwhelmed.

[@UncleDoug]

That's great to hear, RB. We try to make our videos as entertaining and informative as possible.

[@pavelm9078]

Excellent lessons. Glad that uncle Doug is on KZbin.

[@UncleDoug]

Thanks so much, P :)

[@markjohnson9495]

Aside from all I have learned from you after already working on tube amps for years, I love how there will be a random hot rod (or sand rail) sometimes just in frame lol. I know you build cars too, it's just a great addition to your uploads.

[@UncleDoug]

Thanks, Mark. We try to add some variety to our videos to maintain your interest.

[@ScireMi]

Great Video. Was trained in the Navy on vacuum tube technology, in 1974 but your way of explaining these concepts is very clear. Thanks. Keep up the good work.

[@UncleDoug]

Thanks, Mike. Will do :)

[@amitanaudiophile]

This is the master class for learning tone control.thanks a lot sir.

[@UncleDoug]

You're welcome, AA. Glad you enjoyed it;

[@marcmersol7750]

Just wanted to add another thanks. Was working on an amp that made no sense to me after 2nd valve. Your cathode follower explanation was spot on and explained why I was so confused.

[@jenniferwhitewolf3784]

Excellent... as an analog EE, it sure is refreshing to see educational material as well done as this. I will be referring people to this series rather than spend time teaching myself... Well done!

[@UncleDoug]

Thanks, JW :)

[@nilsmclellan868]

No one has ever explained it better than this. Great job man, I’m like super impressed how well this was explain. I finally understand this stuff now. Thanks!

[@UncleDoug]

Glad you liked it, Nils :)

[@lylejohnson7591]

I am 72 and it has been a long time since I was in electronics so this is back to school for me.

[@chrisbraddock3831]

Your videos are the BEST explanation of this stuff I have ever found. You make complex subjects so much easier to understand and apply. Thanks for making these!!

[@UncleDoug]

You're welcome, Chris. Glad you enjoy them.

[@justinc3959]

Fabulous videos, thank you and Rusty for all the hard work! Towards the end of the video you declined to go down the rabbit hole of the full purpose of the resistors and interaction between the capacitors and resistors as beyond the scope of the video - please consider doing another video on that subject, it was the part I was particularly hoping to learn more about! Thanks again : )

[@UncleDoug]

Thanks so much, Justin. Please look at the Valve Wizard site to see his explanation of the LTP phase inversion circuit.

[@outthewaz]

Uncle Doug, unknown to you, I've under your apprenticeship for a while now. Your training videos are very helpful to a wanna be tube amp tech, thank you! I want to understand the why, not just change parts and you provide simple, straight forward explanations that are easy to understand. Hopefully I'll be able to graduate someday..... :) The tone stack video is perfect timing for me, since I've been working on repairing, now converting a Bogen M330A PA amp for guitar (2x7868s). I replaced the Bogen tone stack (treble and bass) with a tweed version, but it ended up too dirty (I might need to move the tone stack location?). My next attempt is the fender TMB tone stack. Your Part 1 is helping me understand and I can't waiting for Part 2 so I can try it out on the Bogen.

[@robert1100]

Boy I really perked up when I heard you mention our British cousins: Marshall and Vox! I've been holding my breath waiting to hear your take on the tone cut of the vox circuit. It's so weird and so crucial to rock n roll! Thanks for another great series.

[@UncleDoug]

I'm trying to get a local vintage Marshall amp in for repairs, RB......so stay tuned.

[@nachom1971]

You are the uncle I always wanted to have. Thanks Uncle Doug!

[@UncleDoug]

Thanks, Nacho.....and you are nicknamed after one of my favorite snacks (plus a pitcher of ice cold beer, of course) ;)

[@nachom1971]

😂 One of my favorite too although people call me a cannibal when I eat them. Nacho is short for Ignacio. Anyways, I am counting on hopefully one of my nephews growing up to love electronics and inherit my guitars, synths, tube amps and love for cars, machines and pets just like you. I'll become their Uncle Doug and I'll show them your videos. BTW I earned an aerospace engineering degree from college and although we had a strong electronics background, not one of my teachers was nearly as good as you. It is very sad because electronics always intrigued me since I was a child tearing TVs and radios open but they sure made me feel intimidated by it. There was simply no practicality behind all the physical concepts and math behind it. I earned really good grades in all other classes, even got a minor in math on the side but it was that darned electronics 2 class that had me drop half way through having to repeat it and leaving an big mole on my otherwise good record!

[@theonlywaytogta6665]

Really awesome explanation of high and low pass filters. Thank you.

[@UncleDoug]

Glad it was helpful, Leo.

[@dtrude000]

Thank you , for all of your knowledge, patience, skill,and humor you and the gang put into all of your content. Just found you through Colleen Fazio . You have inspired me to get into repairs and builds. The Schematic hac been un locked by how you explained . No longer confused. Thank you sir.

[@UncleDoug]

You're welcome, Daniel. Best of luck with your new career :)

[@farfisa5]

Thank you for all of your dedicated work. I'm a visual learner so reading is very difficult, which makes vacuum tubes a very difficult hobby to understand. Capacitors have *always* been difficult for me to understand for some reason (for the past four years I've been in the EE hobby) and you have been able to explain it to me perfectly. You explain *why* exactly how I need it.

[@UncleDoug]

You're welcome, Bob. Rusty and I are really glad that our videos are helpful to you. Thanks for watching :)

[@michaelszczys8316]

So far so good uncle Doug. We’re gettin it. At least most of it. I’m a mechanical wizard and pretty good with electricity but when it comes to radio and amplifier type circuitry that’s where I start slamming into the wall. I’m good with regular resistance, good with transformers and some inductance but capacitors were the cliff to drive over. They’re coming around more and more. That last part of this one with the ‘ why is there a resistor in the circuit ?’ even made sense to me before you even asked that. I just knew they probably worked together somehow, couldn’t explain it, just knew they balance out together somehow

[@UncleDoug]

It sounds like you're making progress, Michael. Keep up the good work.

[@tonyleach5614]

Another great video... I was fiddling around with my amp in my garage looking at the tone stack of my Fender Blues Deluxe amp and my phone alerts me you uploaded a new video about tone stacks! Unreal. Also your cat looks exactly like my cat only mine is a boy and boy is he finicky. I love your videos so keep 'em coming! I'm learning a lot!

[@UncleDoug]

Thanks for the great comments, Tony. I'm glad you enjoyed the video, and relieved to know that I'm not the only owner of a finicky, spoiled kitty :)

[@ianbanhamamprepair9457]

Thanks Uncle Doug, another excellent lesson. I've learnt so much from your videos, can't wait for part two.

[@UncleDoug]

You're welcome, Ian. Positive feedback from viewers (like you) makes it all worthwhile. Part 2 should be posted in the next few days, so stay tuned :)

[@charlesgwyn2115]

Can hardly wait for part 2! I'm working on a tone stack project right now, so this is timely and appreciated info.

[@UncleDoug]

I'll try to get part 2 out in the next few days, Charles. Every time I think it's ready, I remember some additional points that need to be included. Also, I will introduce you to a program that will make your project much easier. See you soon :) ^. .^

[@weshoward4301]

I need to go back over these wonderful videos. Trying to understand what's going on in some of the classic Fender amps (e.g., Bandmaster, Vibroverb et al) where they use a given pot value in the tone controls, but with a 50 or 70k "tap" - not sure how that works or how it's accomplished. But pretty sure it contributes to the uniqueness of their sound. OK self, back to school. This great library is perma-linked in my browser. Thanks again so much Uncle Doug. Surf on!

[@UncleDoug]

+Wes Howard You're welcome, Wes. It's great to hear that the videos are helpful. Best of luck with your self-education and your projects :)

[@FIGSANE]

I had a big OH moment went you were explaining frequencies lol "How frequently the signal alternates." XD

[@davidhorton1277]

Matching the low impedance of the tone stack was the eye opening moment for me. My frequency tailoring experience thus far has been with op-amps and the low impedance of the passive tone control never occurred to me. Great videos. Rusty's path to ground seems to be more appealing to him than his path to camera operator.

[@UncleDoug]

Thanks, David. I'm glad you enjoyed the video.

[@alvagoldbook2]

For me, tone stacks have been one of the most interesting things about tube amps, and has been a big focus of my study. I've been waiting for a well-thought out and elementary explanation like this one. Another great instructional video, Uncle D! Well done!

[@UncleDoug]

Thanks so much, Alva. It is an extremely complex issue, due to the countless tone control variations found in guitar amps. Let's face it, this is the one area where an amp manufacturer can impose some originality on otherwise fairly consistent circuitry. I can't come close to covering all the details, but I will try to provide sufficient detail in Part 2 to give a clear overview of the topic and a good comparison of 4 different (and common) stacks.....so stay tuned :)

[@carlbottcher2177]

Thanks for the effort you put into these videos. I studied vacuum tubes (Valves we call them here in SA.) in college in 1996 doing my Naval radio course. This has been an excellent refresher.

[@UncleDoug]

You're welcome, Carl. We're glad the videos are helpful :)

[@racrx7]

I so enjoy all your tube videos. I’ve wanted these for so long! Thank you!!👍🏻

[@UncleDoug]

Thanks, R7 :)

[@SquidPartyGames]

I very much enjoy how very well made these videos are. A real air of professionalism.

[@UncleDoug]

Thanks so much, Daniel. Rusty and I kid around a little sometimes, but we really try to make the videos clear, concise, and informative. It's good to know that viewers (like you) are enjoying them.

[@AdamRainStopper]

Uncle Doug Viewers like me are enjoying them too! I didn't really UNDERSTAND just how similar (equal and opposite) a low-pass filter was to a high-pass filter until I saw you drawing it out and narrating in plain English. THANK YOU!

[@UncleDoug]

You're quite welcome, Adam. Yes, the two filters are really quite similar in design but opposite in function......which is an unusual combination. It's always good to hear from you. Please stay tuned for part 2, I think you will like it :)

[@AdamRainStopper]

Uncle Doug I will be anxiously awaiting part 2. I need to understand the theory of the cathode-follower better, because I know I can do a much more effective tone control if most of the preamp stages are left alone to drive each other into clipping, then a late-stage cathode-follower takes the ALREADY DISTORTED signal and sculpts it into a mor mixable tone. This is why so many people prefer to have an eq pedal in the effects loop of a relatively high-gain amp, rather than just try to shape the tone early in the signal path, but I don't want to have to complicate a build with adding a separate path for an effects loop. Can't wait to see you and Rusty for round 2!

[@UncleDoug]

An interesting concept, Adam. Please let me know how it turns out. If you are still uncertain about cathode follower theory, then do some Internet searches on the topic and (my favorite) download a schematic that features a CF and study each of its inputs, outputs, voltages, etc. Using this, you can then create a CF within another non-CF circuit. Best of luck !!

[@RC-Flight]

You have an amazing way of explaining electronic circuitry that makes It so easy to understand. Thank you so much for taking the time to produce these in-depth videos. I find them riveting and much more interesting then even the people of Walmart videos!

[@UncleDoug]

Thanks, Glen.....I guess. But now that you mention it, it does take a really good instructional video to outdo the horrors of Walmart :)

[@PeterPug]

I love the way you explain things. I'm sure you are really PROFESSOR Uncle Doug! If not, then please start up U.D. Tone University...you'll have a ton of students...me included. Thanks for these vids...the best on KZbin.

[@UncleDoug]

PeterPug007 You're welcome, Peter, and thanks for the very nice comments. Rusty and I are real happy you're enjoying our videos. Thanks for watching :)

[@jdl2180]

You obviously never been to college because if he was a professor it would take about six years to understand what he made perfectly clear in about 30 minutes.

[@frankymcdonald3081]

Good to see you again. i appreciate the knowledge. Rusty must have a hard time doing camera work with that sweet ride in the garage always beckoning to go see what the girls in the neighborhood are up to.

[@UncleDoug]

Likewise, Franky. I've tried to get Rusty to ride "shotgun", but the shoulder harness doesn't fit him very well and it's hard for him to chew his bone while sitting up :)) ^. .^

[@codebeat4192]

Very useful stuff here, very clear explanation and your funny too with your dog, thumbs up.

[@davey4697]

Thanks Doug for all of your efforts, you are like the teacher I always wanted. I love your videos. So informative and easy to understand. I could make valve amps all day long.

[@UncleDoug]

Wow, thanks so much, Davey. We really appreciate it :)

[@stephenchow5161]

thanks for these videos. make it so much easier to read other books which get bogged down in technical details and losing site of the big overall picture and concepsts

[@UncleDoug]

You're welcome, Stephen :)

[@ZLUNION]

Much appreciated - your talent to educate is very special.

[@UncleDoug]

Thanks so much, John. It's good to hear that the video(s) are helpful and effective.

[@trickyponyamplification9178]

Uncle Doug I just have to say, I truly appreciate your explanations. You lay out the information so well. I refer to your tutorials all the time. I noticed the new tutorial, so I figured it was time to check in at Ampaholics Unanimous and let you know how grateful I am for your help. I look forward to seeing the next one. Thanks Again.

[@UncleDoug]

You're quite welcome, P. It's great to hear that the videos are understandable and helpful. Welcome back to Ampaholics Unanimous :)))

[@vincentcapezzuto5041]

all makes sense-thankyou for keeping it at the level to comprehend without going into nuances-perfect teaching method

[@UncleDoug]

Thanks so much, Vincent. I'm glad the video was helpful :)

[@a_dubs_]

I don’t blame you not explaining capactive reactance. Lol. Amazing video and it helped explain some other concepts for me. Take it easy UD.

[@UncleDoug]

Thanks, AD. Glad you enjoyed it.

[@larrydering1598]

Thanks for a wonderful explanation of the circuit involved.

[@UncleDoug]

You're welcome, Larry. Glad it was helpful!

[@Analoque444]

Thank you very much for absolute all your videos and all your efforts. This is a great channel and I want to send greetings to you and all out there, who watch your channel. Best regards

[@UncleDoug]

Thanks so much, 4N4 :)

[@stevehurd6708]

I love Rusty's enthusiasm! I just found your channel. Love the content!

[@UncleDoug]

Yes, he did tend to be hyperactive at times ;) Welcome :)

[@djvycious]

That beautiful grey cat at 11:33! I had a medium grey like her. Bella was a spicy but wonderful member of our family from 2018 to 2024!

[@UncleDoug]

She was a feral kitten that showed up in our front yard, pregnant and starving. She has become one of the most treasured members of our family.

[@Clayphish]

Wow am I ever late to the party. You are a fantastic teacher and really good at addressing a lot of the questions that develop as you go along! Thanks for have taken the time to make these!

[@UncleDoug]

You're welcome, Clayton :)

[@roymycock413]

Hi Doug, greetings from the UK. Just wanted to say how much I have enjoyed your U-Tube teachings on guitar amps. I am just considering buying a small tube amp to play harmonica through,(Arrrrrrrrrrrr)Ihear you say! anyway the most experienced players say tube amps are best. However, I knew nothing about tube amps except they were heavy and they glowed in the dark(lol) Now after watching your teaching clips I am amazed how easy you made it for me to understand. You have a real skill in taking what I consider to be fairly difficult material and explaining it in layman's terms. In the end though you have imparted the info so that I feel I have a more technical understanding of the subject rather than just a layman's view. I am watching the material several times, just to try and make it stick! I am no spring chicken (68) so the memory is not what it used to be. I am looking forward to watching more of your clips but in the mean time, once again, thank you so much for your time, effort,expertise,dedication and the inspiration you have given me through sharing your knowledge. Just one more thing, have you ever done a clip on hand wiring a small amp from scratch. I have seen the one where you make the chassis and the cab etc but its the actual wiring I am talking about. I can do all the making of the cab and chassis, but when it comes to the actual wiring up I am not too good at following schematics. I would love to build my own simple amp like the one you made in the clip, so if you have any plan of attack written down or u-tube clip ( like wiring it a section at time etc) I would love to hear from you. I know it must sound like I am asking for the electrical equivalent of (painting by numbers) so to speak, but if you don't ask you won't know if there is anything out there! Many Thanks Roy M.

[@UncleDoug]

Greetings, Roy, and thank you for your very kind and thoughtful comments. I'm glad to hear that the videos are helpful. I think the problem with wiring stems from an inability to interpret schematics. They are like a map for the circuit, providing specific information as to every connection and component placement. A video showing how to connect a wire from one terminal to another would not be particularly instructive, and the ability to interpret schematics is not something which can be effectively verbalized. It's more like learning a new language. You must develop a vocabulary, an ability to translate symbols, and then practice a great deal. Download the schematic for a 5E1 Fender Champ amplifier and study it carefully. Divide it into sections, pre-amp (12AX7), output (6V6), and power supply (5Y3). I have posted videos explaining each of these sections. Learn the symbols for capacitors, resistors, transformers, tubes, etc. Trace the high-voltage (DC) from the power supply to the tube plates. Trace the signal from input to output. Trace the AC to the tube heaters. Once you have mastered the simple Champ, try a more complex circuit, like the Princeton. It will require time and effort, but these are things that you must provide if you really want to achieve a better understanding. Good luck.

[@donaldfilbert4832]

Great Video Uncle Doug !! Rusty did a great job keeping the camera steady !! I am looking forward to Part 2 !!

[@UncleDoug]

Thanks so much, Donald. Rusty is nervous that he may lose his job to the cat. A little workplace competition is always good for productivity :)

[@hendrix5757]

I personally would've enjoyed the decision towards the end, when you chose not to break down all the various 'hows' and 'whys' regarding a resistor's innate functionality within RC networks, if you could've simply briefly supplemented a couple small examples generalizing the relationship between the size of a resistor and the capacitor's overall selectivity in frequency bands. LOL but acknowledging the borderline nit-picky nature of this request isn't lost on me whatsoever haha! I supremely dig all of your channel's content and the overall manner in how you layout all the various concepts and processes pertaining to the respective subject matter in a slightly compartmentalized, albeit, streamlined fashion! This level of commitment, discipline, and plumb dedication to provide a means of formidable education to the public deserves any/all the acknowledgment and success in this lifetime!

[@UncleDoug]

Thanks for your very nice comments, H. There are always ways that a video could have been better, but we simply try to do the best we can in a reasonable time frame.

[@nelsondejesus2796]

Hey Uncle Doug, Thanks for the great theorizing of the circuits components and their basic variables. I saw alot of what the great designers like Leo Fender,JimMarshall, Tom Jennings,Dallas Reeves, to name a few including the bolstering of the latter Randall Smith of Mesa to the Soldanos had in mind and the overall designs of passive to active. I use a downloaeded Tonestack Calculator and it makes it easier using your input to achieve a great deal of information I either didn't have or didn't understand.!! I've seen you explain many of their concepts in depth! It's more than just adding or changing a resistor, or capacitor here and there, but I didn't lose interest and best I could at least rewind and start again!!! I have an incredible amount(s) of bookmarks and have applied alot to my own works,..I noticed this last forum also relates to the basic use of the .001uf for the ''Treble Bleed'' on my guitar's Volume pot and Tone control. After awhile it all seems to make sense, please keep up the great works!!

[@UncleDoug]

You're welcome, Nelson. It's always good to hear from you. Rusty and I will do our best to keep up the video production.....as long as you promise to keep watching :)

[@garyadkisson4790]

Thank you so much! I am fairly new to the tube amplifier circle and have read and studied for a while now, but you have given me more understandable knowledge in your videos then I have found in any book! By the way I started working on amps because the pole dancing gig wasn't going anywhere.... Again thank you. Can't wait for the next one

[@UncleDoug]

Hi, Gary. We have mixed emotions about your comments. On one hand, Rusty and I are quite flattered (and happy to hear) that our videos are clear and helpful.....but we are also saddened to learn that your pole dancing career failed to materialize. I'll speak with Anastasia when she brings over her Fender Tweed Deluxe for a "tube biasing", and see if she has any suggestions. Meanwhile, thanks for the nice comments and best of luck with your interim career in tube amps !! :) ^. .^

[@ClarenceHW]

Even though I know the operation of capacitors in passing frequency but had never though about it being in terms wavelength.. The low pass filter is why we see orange-red sunsets, or a full moon eclipse is often a ruddy red. :-) Our atmosphere is a low pass filter. Lucky for us, or we probably wouldn't be here...(at least in this form) Great job with these instructional videos, thanks much!!

[@UncleDoug]

You're welcome, Clarence. I like your analogies and observations.

[@ClarenceHW]

@@UncleDoug Thanks, same reason we hear the hip-hop bass from two miles away yet nothing else of the recording, the longer the wavelength the further it travels in our atmosphere. :-)

[@UncleDoug]

Excellent observation, Clarence. The power contained in bass frequencies is much greater.....which is why sub-woofers have their own power supply.

[@MrBrymstond]

Uncle Doug I see people are smartening up and subscribing. If you want to really learn, it's all you, but if all you want is to see someone shotgun parts to make an amp work well just about any KZbinr can do this, you are a great teacher. You troubleshoot and hit the spot and offer modding to make it more beefy or less, kinda like electrical porn. I'm 58, Brad the Guitologist could be my son and he knows more than I do, I was late in this game, but worked many of others, but lately I'm figuring out more and more on his site and stop the video and make a comment. More and more I'm getting it right and have to go back to delete my comment or reply saying what I did thanks to you. Thank you...

[@UncleDoug]

You are quite welcome, Mr. B. We're glad that our channel has been helpful to you and wish you the very best.

[@AlexanderShibilski]

I've always preferred the plate driven tone stacks. I tend to like a lot of sculpting capabilities

[@kevinking2468]

Uncle Doug - Thanks again for the superior instruction!!!

[@UncleDoug]

You're quite welcome, Kevin, and thanks for the kind appraisal :)

[@patprop74]

Interesting stuff Doug, I am about to attempt my first tube amp experience with converting a PA system, it basically just has one tone knob, this is helping to give me a clearer direction on what needs to happen. Thank you Doug.

[@UncleDoug]

You're welcome, Pat. Good luck with your project.

[@EddieLeeFunn]

Rusty, at about the 1:30 mark: "Yeah, no... not feelin' it today, Doug!"

[@UncleDoug]

That pretty well described Rusty at any and all times ;)

[@pleximanic]

The best explanation of tone stacks, low and high pass filters I have ever seen! This topic can not possibly be explained better than what Doug does here! The grade is at least 100 points out of 10 possible. Doug, are you trained in electronics at the military or have you taught yourself? Outstandingly great work! Thanks Doug, you're a great man!

[@UncleDoug]

Wow....thanks so much, Plexi. I am entirely self-taught, mainly by internet study and lots of personal experimentation.

[@pd4165]

Loving the channel, Uncle Doug. It's a pleasure to watch.

[@UncleDoug]

Thanks so much, PD....glad you like it :)

[@JesusIsLordofMybeing]

Thanks again Uncle Doug!!! You are truly an amazing instructor!!! Funny with your pets as well!!! Thanks again!!

[@UncleDoug]

You're welcome, Jt :)

[@deemac7551]

Such a great help. Great, great electronic teaching.

[@UncleDoug]

Thanks, Dee :)

[@68MalKontent]

Very nice video, the tale of the judgemental capacitor is just sweet :) You wrote somewhere, that Rusty does all the script writing, so no wonder he's not interested in mere camera work, having written such a masterpiece ;)

[@UncleDoug]

Thanks so much, Stan. Yes, Rusty vacillates between cinematography, script writing (and editing), and mastering the Lydian Scale on his '59 Les Paul.....he's a very talented and versatile hound :) ^. .^

[@yrulooknatme]

Older video but a great one... Thanks

[@UncleDoug]

Thanks, YRU :)

[@huberttremaine8343]

Another brilliant video! I hope I'm not too late for #2' and request Baxandal tone controls like what Ampeg uses. If not maybe sometime in the future. I'm sure it takes a lot of time and effort to make these videos and you sharing your vast knowledge, is giving guys like me the courage to repair, design and build our own tube amps. Thanks!

[@UncleDoug]

Thanks so much, Hubert. I have not finished Part 2 yet and will include the spectrum of the James-Baxandall passive tone stack. It should be noted that the Baxandall tone circuit yields flat response which is generally better suited to HiFi and Stereo amplification than to guitar amplifiers (for reasons that will be discussed in the video). Thanks for the great input !!

[@justinblee]

Wonderful video and great instructional design. I loved it!

[@UncleDoug]

Thanks so much, Justin. Rusty and I are glad you enjoyed the video :)

[@t1d100]

Outstanding information, presentation and clarity! Thank you!

[@UncleDoug]

Thanks, T1 :)

[@rolyart3]

Wait…there’s a “Russian pole dancing video”?! Thank you so much for videos like this one! I have referenced your videos so many times. They really have enhanced my love of tube amplifiers.

[@UncleDoug]

Yes, indeed, Roly.......and they are a sight to behold. We're glad you enjoy our videos :)

[@Impractical_Engineer]

Wonderful video, it's simply amazing how well taught this is and easy to understand. Thank you for all the time you put into this.

[@UncleDoug]

You're welcome, Brian. Glad you liked it.

[@patomara3013]

Thanks very much for the time and effort that you devote to passing on your vast knowledge. You have been such a huge help to me in my journey of learning this difficult skill and I want you to know that I appreciate your generosity very much. Cheers from Pat down under.

[@UncleDoug]

You're quite welcome, Pat. Thanks so much for the very nice comments.

[@rheidtech]

Glad to see ya. Your knowledge is priceless. Great video. No russian pole dancers for me. Lol. ( pretty much wanna know your half hour lesson on that resistor. );) cool tube frame

[@UncleDoug]

Glad you liked it, RH. Stay away from those Russian Pole Dancers.....they'll elevate your plate dissipation to dangerous levels :)

[@corralesdavid]

Glad you're back with videos! Amazing as usual :)

[@UncleDoug]

Thanks, David. It's good to be back :)

[@ronniewall1481]

Very nicely done.

[@smccaskill5515]

This is a remarkable presentation and truly gives practical information we can all use! Thank you! Stuart

[@UncleDoug]

You're welcome, Stuart. We sincerely appreciate your very nice comments :)

[@spaceblues5972]

This is so helpful, I'm glad i found this video

[@UncleDoug]

So are we, SB. Welcome aboard.

[@brianpotter7520]

"THANK YOU" so much for your videos, I have wanted to get into how amps work for along time, your videos have helped me learn so much, I have a lot to learn still, but I feel like Im finally on the right track. you just can't go out and have someone teach you how to build your own amp. Rusty is the coolest too

[@UncleDoug]

You're quite welcome, Brian. Rusty and I both appreciate your interest and input. We hope the videos are helpful and that life treats you right :) Best of luck !!

[@flaconsius]

Very easy to learn video. Thak you very much for sharing your knowledge in such a way. Regards from Argentina.

[@UncleDoug]

flaconsius You're welcome.....glad you liked it :) Best wishes from Rusty and UD.

[@tubical71]

Hi Doug, as usual you have just done a *great* job :) As for 10:00 and up, you may check the whole thing from the manufacture´s point of view: 1) tubes are expencive, so why we need another one, in this case a tube witch does not amplify? Because the 12AY7 here is cheaper than the pots you will need when the 12AY7 is not in there....The pots you´ll need without the 12AY7 would be 10x higher, you´ll need to have 10meg inside. They are hard to get, and not cheap. Today they are no longer made anyway. The only high impedance pots are the 1meg types.... 2) if you put 10meg pots in, just because you can, will result in a very noisy Amp, because 10meg just picks up *any* noise around. Very good sheelding would be needed. And if you gonna touch the knob of the pot the whole amp would produce hum immediately. Thanx for this one, Doug!! :) Can´t wait to see Part Two!

[@UncleDoug]

Greetings, TC. I enjoy reading your comments because they always add some interesting info and details to the discussion. You make a good point about the financial benefits of a cathode follower vs three (more) expensive pots. I think we often fail to understand that many of the decisions made regarding amplifier circuit design are based on increasing (or maintaining) the profit margin, rather than simply optimizing the tone or function of the amp. Amp building was, after all, a business rather than a humanitarian endeavor :) Thanks for your kind words and knowledgeable input.

[@tubical71]

Uncle Doug Amp building is in *first place* a business, sorry to tear of some sparkles from the companies, but in fact they just stole some ideas from each other. Fender did that from the earlier gibson amps, while marshall just copies from fender (bassman). In fact the first marshall amp was a bassman clone. Furthermore (if you put faith in these companies - please do not read on) They don´t know how to build amps. As if they would, they simply would/will build them completely different. (besides that; the schematics are ok - to point that out!) I was in some of them. And the way they ground the components just put tears in my eyes. If only they ground the components like a good audio designer would do it, the Amps would be a *lot* more quiet (no hum and *no* noise) And when i say a lot i really mean it. -90dB total SNR would be easily achieved just with good and *propper* grounding. *One* ground terminal, where to put *all* ground pins and *one different* point of the chassis where there is *one* wire going to is propper grounding. This is rule number one for serious audio design... Isolation of all terminals,pots and jacks from chassis, or if not possible ground them with *one* and very *fat* wire together and put this on main ground. That is rule number two....and there are much much more of these to follow ;) But i have to say this, i like Instrumental Amps very much anyway. Even my very noisy Laney "Super PA"

[@GregsGarage]

TubiCal I love reading the discussions you two have. Just adds another layer of frosting to this cake. Thanks.

[@UncleDoug]

I don't blame you, Greg. TC is extremely knowledgeable and helpful. His comments are always worth reading and generally add an extra dimension to the video.

[@tubical71]

Many thanx for the flowers Doug and Greg. Audio electronics are my passion since i got my first tube Amp when i was around 12 years old. I found it in the streets, where we used to have a sort of bulk garbage. All big unwanted stuff that doesn´t fit in your garbage bin could be placed in front of your property once a month and have been picked up by local litter service. That good old days it was easy to find tube based gear, as old TVs/Radios/HiFi and Tube based record players. These ones i liked the most, since it was very easy to pull out the Amp chassis and play around with it. Nowadays this is not possible anymore due to some strangers who just to snoop around and spread everything around the streets. So everything has changed. We have some disposal companies where one can put every electronic stuff and they do not give anything away...

[@mudylafeet]

Another great video, my learning curve keeps climbing lol cheers!!

[@UncleDoug]

Greetings, Mudy. May your learning curve be as vertical as Anastasia's pole ;)

[@kimarbella]

Thank you so much!! You're this moms' favorite professor. I subscribed and shared

[@UncleDoug]

+Kim Orellana You're welcome, Kim. We really appreciate it :)

[@paulburland8278]

Nailed it again. Thanks Doug (and animals).

[@UncleDoug]

You're welcome, Paul.

[@JFiligrani]

Doug: "Kitty? 'r you ready to take over the camera work on this video?" Cat: "I'd be ready to take over the world, if I only knew how this strange thing worked..." I love cats :) I hope she's nice to rusty!

[@UncleDoug]

Greetings, JF. They have a mutual non-aggression pact. Rusty sneaks in an occasional sniff, but otherwise they try to ignore each other.

[@BSpenceTravels]

Another great video, thanks for the clear explanation.

[@UncleDoug]

You're welcome, Brian. I'm glad you enjoyed it.

[@michaeld8975]

I was listening to this as a podcast right up until we got to Russian dancer and thats when I put down the soldering pen.

[@UncleDoug]

I hope you put the soldering pen down so you could turn up the volume and take notes, MM.....not to do a quick KZbin search for "Russian Pole Dancer" :)

[@ml7014]

This is making sense to me now. I thank you Sir.

[@UncleDoug]

You're welcome, Mitch.....glad to hear that the video was helpful :)

[@joshuarego5161]

You are an amazing teacher thank you for sharing your time and knowledge.

[@UncleDoug]

You're welcome, Josh :)

[@MM-ib6qh]

Your videos are gold. Thank you!

[@UncleDoug]

I'm glad you enjoy them, MM.

[@marvinkentvillamor1570]

thank you very much for this Uncle Doug.

[@UncleDoug]

You are very welcome, Marvin.

[@dzamija922]

thanks for the awesome explanation rusty

[@UncleDoug]

Woof :)

[@jeffb6161]

thanks for a great explanation, of a very complex situation. wow back to the drawing board!!

[@UncleDoug]

+jeff b You're welcome, Jeff. I don't grasp all the complexities either, but the Tone Stack Calculator in Part 2 is an invaluable resource that saves a lot of time when designing a tone stack.

[@jeffb6161]

thanks, I will be sure to watch part 2 as soon as possible, was thinking of adding tone control to the HiFi I have been building.

[@UncleDoug]

You're welcome, Jeff. HiFi tone controls are often active, rather than passive, so you might want to do some research in both types of control methods.

[@jeffb6161]

ok, will look into active and passive. Need to get back to the amp soon, has been sitting at the back of the bench, gave up on it for awhile trying to learn more. Only problem I have now is hum at zero volume. Should I have source or music ground connected to the volume pots? Think the hum is the preamps gaining ground at zero volume. When I turn up the volume pots the hum goes away. Thank you Doug, say hello to rusty!! And jack

[@UncleDoug]

You're welcome, Jeff. That's a strange problem. I've heard of hum that either obeyed or ignored the volume control, but not hum that was inversely related to the volume setting. I'm not familiar with the concept, but perhaps your theory is correct and at zero volume, the ground (chassis, I assume) is acting like an antenna (?) Since I assume that your chassis (ground) is, itself, grounded via the wall receptacle, you would think that any signal generated in the chassis would go to the earth ground. Very mysterious.