1966 Marshall JTM-45 Mk II in for Repairs......A Rare and Wonderful Gem !!
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- Опубліковано 27 тра 2021
- This video documents the repair of a splendid 1966 Marshall JTM-45 MkII amp sent to us for repairs. The initial problems cited were a "gap" in one of the volume controls and a tendency to "red-plate".....but, as you will see, other issues arose. Also, due to the "special nature" of this wonderful old amp, we sought to make component substitutions as unobtrusive as possible.
In addition, we open some gifts from a very generous viewer.....with Jack and KC's help, of course.....and feature a second video showing one method to repair a "scary" problem in a BF Super Reverb.
Thanks to all our Patreon patrons and PayPal contributors for your continued support, and to all of you who helped us reach the lofty goal of 100,000 Subscribers !!! Way back when we posted our first video on YT, we never dreamed things would turn out this way......and they would not have, without our wonderful viewers. Thanks for making this such a rewarding experience.
If you would like to support our channel, please consider becoming a Patreon patron at / uncledougsvintageamps or making a PayPal contribution to dldcam@aol.com. Regardless, we really appreciate your time and interest in our channel.
Who needs Netflix when we've got 76 minutes of Uncle Doug ?
Thanks so much, Giuseppe :)
Exactly!
Agreed!!
Bravo.
I know! My wife couldn't wrap her head around why i enjoy these so much, then she started loving to listen to him and she is not even a musician! I also steal many of his "Uncleisms"! One of my faves: we have wires hanging like a dis-embowled Antelope!😄
Hooray! an hour of amp fixing and dry humour!
I hope you enjoy them both, Daniel :)
Me as well Uncle!! I wish i would have had a teacher like you when i was younger! You make learning fun!
Delightful.
I cant imagine a thumbs down for unc!!
... and music!
Uncle Doug is my favorite amp repair guy. His knowledge is very good and his attitude is the best. It is no wonder that people send him so many gifts. He is a wonderful human being. The world could use several billion people of his demeanor. The work displayed in this clip is highly commendable. Pretty much the norm for Uncle Doug.
Wow....thanks so much for all the very complimentary comments, Tony :)
agree . . .
@@UncleDoug will leave the most revered comments.
@@iceWaterProductions1 Thanks :)
A few comments on the video: 1.) I say "6V6" instead of "6L6" at 1:11:20. 2.) Thanks to Robert Set for the opening musical montage and logo. 3.) We tried jumpering Ch. 1 & Ch.2 for the audio demo, but for some reason it did not record well. 4.) It should be noted that Jim Marshall himself did not actually build the amps.....this task was done by Dudley Craven and Ken Bran.
Definitely feeling the opening montage.
Although Jim would frequently be covering cabinets in the early days and his signature can be found inside...
Who has a better story than Bran? jk
"Well, greetings out there in UA-cam land...." - when I hear this I know we are in for a treat! Thanks for the amp tech videos Uncle Doug!!!
Thanks !! I hope you enjoyed it, Charles.
Doug can give us British a lesson on dry humour :)
My Temptations starts now, I purr.
@@PandemoniumMeltDown maybe Jack or Casey will share their treats with you :) 🐱😺 meow
You generate a whole new respect for quality work on quality equipment. You go the extra mile.
Thanks so much, Cloyd :)
Uncle Doug getting a new video out means to stop anything, grab some tea or coffe and getting into yet another great repairing session with great humor :) I will need to get one of these Marshalls, some day...
Thanks so much, Andre. I hope you enjoy it :) We all need a JTM of our own :)
Check out the new Marshall Studio amps... while they are PCB instead of hand wired, their build quality is outstanding. Fact is, Marshall could teach Fender (and others) a thing or two about amp design.
Stop anything and grab some tea to watch ? André, do you have a spycam in my living room that I'm not aware of ? 🤔 I was supposed to start working, but got « distracted » by Doug's entertaining offering 😂
"When I grow up I want to be a guitar player. I want to be able to have enough money so I could buy a huge amp named a Marshall Full Stack."
I wrote this for a school paper when I was 12 years old! Still don't have the Marshall but the neighbors thank me for that
It never hurts to dream :)
Wow that tip on stopping the high frequency oscillation was absolutely fantastic. I really appreciate that. Thank you so much, I will store that in the old memory banks. Great stuff.
Thanks, Leonard. Glad you enjoyed the video.
I'm just a guitar player. No electrical knowledge before finding your series of videos. I am always fascinated watching you work and explain all of the dark voodoo magic of electronics. Your attention to detail (respectful reverence?) towards this 66 JTM45 was awe-inspiring! I hit the thumbs up while wishing there was a guy standing on his chair applauding wildly I could trigger to let you know how much I appreciate your desire to always go above and beyond! Cherry custom shop work!
Wow....thanks so much for all the very nice comments, Kieron. We really appreciate hearing from you.
Hi, I really enjoy your videos for many years. I wish I lived in Texas to talk you into letting me apprentice with you. I could learn more than I do from your videos alone. Thank you for your teachings. I've learned so much from you.
That's great to hear, Steven. We're really glad the videos are helpful and informative.
This Watches so easily it is dePendant on our so knowledgeable host..We appreciated seeing your Jewels and hearing your Pearls of wisdom. We also saw a beautiful Chain of two amps in this video and they were Ringing so delicately by the end. Uncle Doug you are a Diamond.
Wow....thanks for all the gem comparisons, IL :)
Superb video Uncle Doug. Some very innovative cosmetic enhancements with the capacitors that preserve the visual integrity of the amp. So much so that I consider the film to be worthy of mention and inclusion into the Smithsonian archives. We took these amps for granted many years ago here in the UK, so nice to see yourself and others appreciating and maintaining what you rightly describe as 'Jewels'
Thanks so much, F2 :)
Congratulations Doug on achieving your 100,000 subscribers -you thoroughly deserve it. The knowledge and the humour with which you pass on that knowledge makes every video a treat. Thank you for all of the effort that you put into each video. Thought that you might like to know that our new puppy - Penny is totally settled in and is proving to be a fantastic little character. She has brought a smile back to our faces after all of the health issues that I have and continue to have. Take care and it’s great to see you and your animal family back.
Thanks so much for all your kind words, Robin. All our love to Penny and best wishes for better health.
I was lucky enough to own a '64 or '65 variant of this amp between 1969 and 1974 here in the UK. It had the Marshall name in a solid Perspex plate, and the knobs were the larger variety with brushed aluminium faces. Other than that, the amp here seems pretty much identical, with the weighty transformers and the KT 66s. I loved that amp, but it had a chequered history. I once loaned it to a pal, who forgot to connect the speaker cab and promptly burned out the output transformer. Then I had it stolen - twice! The first time it was recovered thanks to a diligent police detective and a pretty stupid thief. The second time, it was lifted from the band's van, and that was the last I saw of it. So thanks for the memories, Uncle Doug! Always love it when a new video appears.
Sorry to hear of your loss, David, but thanks for sharing your experiences with us :)
This my old amp! Of the hundreds of Marshall's I've owned, this was the BEST Marshall I ever owned! Should have never sold it...lol. Happy to see it's pretty much in the same condition as when it left me!
Wow.....it's a small world. Thanks for the input :)
I can't tell you how much I appreciate your tuition, passion, love, care and respect for the craft. You truly are an inspiration and my favourite educator in this field by far. The efforts you go to to bring us these videos and the knowledge passed on during them are truly appreciated. Thank you, really. Best, Scott.
Wow, Scott, what a wonderful series of comments. We truly appreciate your kind words.
Such a wonderful attack / decay and shimmer on this amp! Yes indeed , a hit maker in the studio !
Who else exploits the incredible clean Marshall settings.
@@karst41 Hendrix for one
I agree, Enid. One of my guitarist friends commented on the "chord bloom and chime".......it's a very special amp :)
I have never in my life heard a Marshal clean channel sound so nice over yout tube , holy cow batman
Thanks so much, Jerry. High praise indeed :)
Baby A-be (Abhinna, Abe for short) loves to fall asleep to the steady even voice of uncle Doug. Works every time. Lol
I had the same effect on my students back in my teaching days, Nathan. Seriously.....glad to hear it.
I never try the dangerous stuff at home. I used to do it at the neighbor's, until the fire... Anyway, great video! Thanks UD!
Safety begins at home, FWR......to heck with the neighbors ;) Glad you enjoyed it.
Congrats on that new intro, Uncle Doug!
Thanks, David. It was created by a viewer from Poland.
sounds silk smooth ... you are a magician
Thanks twice, Bruno :)
Thanks uncle Doug for the 2nd part of the video. The current limiter can really save tonnes of money as well.
And in the first video, the sound of the JTM with P-90s is a killer. Wow! 💪🏻
Glad you enjoyed the video, Shade.
Congrats on reaching 100K subscribers! You're the best repair person on UA-cam!
Thank you so much, Jeff 😀
100k IS quite a milestone. Well done - it is an acknowledgement of the quality of your channel!
Love the new intro.
Created by a very kind viewer, from Poland, I believe :)
I was an electrical engineer working with a physicist and a chemist to find out why Aluminum electrolytic capacitors were blowing up on jet fighters in 1984. I had to pick up capacitors with tweezers so I would not weigh my fingerprints when measuring outgassing. The upshot was Sangamo had epoxy end caps made with an out of control amount of thickener allowing solder flux cleaning solvents to get inside the cap and attack the wire to Aluminum connection. Sangamo went out of business.
For those of us familiar with Sangamo capacitors this is very interesting, Clark. Thanks for sharing.
@@UncleDoug The military electronics company that employed me in 1984 did not cause Sangamo to go broke. My boss said that bigger commercial consumers WOULD be having the same trouble.
Man Uncle Doug your attention to Detail and keeping this amp looking original is awesome I can’t believe I missed this video .
Thanks, Ricky. Glad you enjoyed it.
Uncle Doug, love the channel, your attention to aesthetics and electrical precision makes it “must-see TV”! Congratulations on reaching 100K subscribers! Next goal is 250K. We’re all pulling for you!!!
Wow....thanks so much, Gerald :)
Why am I strangely drawn to watch these videos 3 and 4 times.....what's wrong with me!!!
Sounds like a case of good taste to me, R&B ;)
Look I dunno what the hells wrong with you rnb, but stop spreading it round will you ok? It could could be the next pandemic.
I never miss an Uncle Doug video.
Were honored to hear it, Peter :)
To be honest with you, I have never opened up an amplifier, however I love electronics and watch as many videos about different aspects of the subject as I can. I do love your videos because of the way you go into what is happening in a circuit and how each component can have such a drastic effect on the overall operation of the unit. Thanks a million for being one of my instructors, it's like being back in college once more, except instead of law, I am learning electronics!
Thanks so much, Jerry. We're glad the videos are informative :)
Here's a saying that I heard all the time about these amps.
"It's only 45 watts, like a Bassman .... but those are British watts !" LOL
After being blasted by one of these jewels, I concede the wisdom of that statement, Zanky :)
@@UncleDoug , are those "keep calm and carry on" watts, "stiff upper lip" watts, or "get on with it!" watts? 😁🤔
@@goodun2974 Seagoon Watts.
RMS rather than peak measurement ?
@@highpath4776 "Seagoon"? Some British phrase which, as an American, I am not familiar with?
Super professional repair! What a Classic old amp. A dream amp in pristine condition. Thanks Uncle Doug 👍
You're welcome, Bob. So glad you liked it.
Why would anybody put a "thumbs down" on a video like this? The dude is trouble shooting a 55 year old amp that he has never seen before. Great Video!
Thanks so much, Lev. Don't waste any concern on the slobbering coward(s) who deface those videos they envy the most ;)
UD IS THE BEST ENTERTAINMENT AND TECH INSTRUCTION IN THE WORLD
Wow......thanks so much, Rax :)
Thanks so much for everything you do, Doug. I have learned a ton. Love the snazzy intro, too. You're the coolest Uncle I never had!
Wow....thanks so much, Matthew :)
Congratulations on 100k! The Marshall sounds great with all the pickup varieties and your work looks fantastic!
Wow....thanks so much KM :)
I can't tell anything unless it's dimed
Those original GEC KT66s are nearly indestructible... great video.
Thanks, Hilario :)
Genalex
@@vayabroder729 Both are the same. General Electric Company, Ltd., Magnet
House, Kingsway, London W.C.2,
England
Osram Marconi
There he is!!!!!!!
The king is back!
Thanks so much, guys :)
I see super amp tech has been here. A sad, lonely down vote. I have a dilemma now, because I am not super motivated to work on a Friday before a holiday weekend and Uncle Doug drops some amp goodness on us. I think a long lunch is in order.
Take the rest of the week off, Paul, and join me in scorning the slimy coward who voted "thumbs down" ;)
Uncle Doug rides again!
Thanks for joining us, Bill :)
I am glad to find this channel. I am planning a couple of upcoming projects to keep my brain busy. Both being replicas of vintage Marshall amps. One being a jtm45 and the other being a jtm45/100. I want to be as authentic as I can be so great to watch these videos.
We're glad the videos are helpful, William. Good luck with your projects.
Reaching in to turn off a switch when something is going wrong takes resolve. My old computer got rained on outside, I let it dry out in the house for a couple days and when I plugged it in it sounded like it was going to explode...I jumped across the living room to dive out the second-story window but stopped myself and bravely ran back to unplug it. I then went to the window to catch my breath and looked down at the rocky cliff I would have landed on...definite turning-point in my life. It's all fun and funny when you survive.
I am braver when a customer's amp is at risk. The thought of having to tell them it went up in flames is worse than actually being engulfed in those flames ;)
@@UncleDoug good laugh !
ERIE caps are definitely original, I replaced a handful of them in my vintage Laney Supergroup.
Thanks for the info, SK.
@@UncleDoug It was originally an american company, but i found some information about the UK branch:
www.ourgreatyarmouth.org.uk/page_id__455_path__0p3p41p.aspx
Highly doubt that it’s an original, most likely the cap would have been a Radiospares. Never seen an Erie in a mid 60’s Marshall unless it was a replacement.
@@MichaelJWane Well maybe it's not original for Marshalls but I believe Laneys are built with them, because in all the pictures you can see them.
Actually that amp would have been Hunts (taken over by Erie in 1969 so no, not original
Good job. However, you're cutting your clips short in editing cutting what you're saying off mid word/sentence.
The editing program cuts at even seconds, not fractions of a second, so occasionally a word may be truncated. I reviewed the video several times and only noticed this once or twice......which, hopefully, did not ruin the whole video for you.
@@UncleDoug Nice to be told why.
Uncle Doug! That repurposing of a 1940s jukebox power cord shrowd was GENIUS! Worth the price of admission :) (25:40)
Thanks so much, David :)
Uncle that sounds fantastic brother, you're a genius.
Wow....thanks, Harmon :)
Another fine amp repair video from Uncle Doug! Two landmark amps, a JTM 45 & a Super Rvb! So much to be learned from your electronix expertise. --> Thank you for your candor 😉
Thanks, Rich. So glad you enjoyed the videos.
How can something be so enjoyable to watch ... even though i haven’t a clue what doug is talking about .
Wish i new more about electronics .
That's kind of you to say, Graham. Keep watching and it will gradually become much clearer.
Definitely go through Uncle Doug’s back catalog and I can also recommend the channel Mr. Carlson’s Lab.
There is life on youtube. Such an ignorant viewer as I, getting a peek behind the curtain. Thank you. I watch these in (mostly) mute amazement.
Thanks, Clay. We appreciate your time and interest.
Doug at 56:43 -57:08 I was really feeling it and diggin’! I liked all your playing, but that was where the real magic took place!
I'll tell Ollie and Jack how much you enjoyed it, MR. Thanks :)
Uncle, you are a genious.
You are too kind, Ulrich.....but thanks ;)
Oh yea! Time to sit back with a bowl of breakfast popcorn and enjoy Uncle Doug and Jack.
Breakfast Popcorn.....the breakfast of champions !!! Thanks, Raiden.
You're so good UD, I'm not going anywhere anytime soon. I can only see your channel grow and grow. Heck, you made me go from "hmm what, let's watch this simple thing again" to "caps are bad" and "thank God for the current limiter" before you've said it. I know your teaching works, because it works. And your ethics are second to none. You are an inspiration and a great place to take knowledge as far as needed: all the way.
Thank you and keep at it my good sire!
Wow....thanks so much for all the very nice comments, PM. We really appreciate them and will definitely keep at it :)
More to the point than I could have been.
Uncle Doug is a master of documentation. I have 3 hard drives with my life's work on them. I just finished a Fender 5F11 with the selenium recto. I used the 330K across the 56K and 1N4007 diode anode to the 10K. Bias set at -31.00 vdc. I love these videos. I have been doing repairs for 45 years +. Don't think you know it all. At times you will run into something stranger than fiction. It's the little overlooked things like a bad speaker,Bad Volume pot or tube socket pin that is corroded and will not clean up enough to even make continuity. I said to myself one day, (Why don't you make a file to scrap a preamp tube socket. I wound up using a D string from an acoustic guitar that perfectly fits most any preamp socket and cleans (Files) the socket pins as new. I had a 5E3 vintage amp that would not turn on the cathode feeding the 6V6 power tubes. All the cleaner Deoxit in the world made no difference. Problem found and solved with that D string.. I'll never forget that discovery! I still use it when in doubt.
Thanks for your helpful input, TA. I'll give the guitar string suggestion a try :)
With B+ drained of course. @@UncleDoug
Always, TA :)@@triodeamplification5568
I've got to tell you I'm severely burned out. But if I have 5 amps in here I just have to pace myself and especially parts orders. And worst case scenario of the occasional bad tubes new out of the box.
I sympathize with the burn out. I have to take some time off occasionally to recharge the old batteries.@@triodeamplification5568
I was just noticing that the tube retainers are of more recent vintage than originals which would have been those funny looking knitted bonnets like tea cozies. I think they were fiberglass. I do remember being amused the first time I saw them, I pictured little old grannies knitting away in the Marshall factory making "valve bonnets"!
Thanks for the info, James :)
Above and beyond with that Erie concealment cap. Really nice work Doug👍
Thanks so much, Rob.
Watching this makes me want to build a 45. In 1970 I bought a Marshall Major 200 watt full stack , talk about a wall of sound. Thanks for the video great as always.
Glad you enjoyed it, Dennis :)
I think it was Ken Fischer (Trainwreck Amps), formerly of Ampeg, who said he put Mullard KT88s in a Marshall Major and "sailed past the 300 watt mark".
Wow Dennis that setup must have been so awesome! Especially if you can play well.
I reckon if we can all get into servicing and maintaining all these old classic tube amps, we can save them from being tossed onto the waste piles so that future generations of musicians can get the opportunity to enjoy them, it's also good for the environment too.
Let's hope so, Simon :)
I really enjoy yer videos. Keep up the great work and videos. I'm 70 now and still jamming. Rusty in eastern Tennessee
Glad to hear it, Rusty. Keep up the good work.
Dear Uncle Doug and Jack, reg. the trimpot - it is not part of original circuit, and as you mentioned, obviously was built in years ago. Great video, to have the chance to look into the heart of the holy grail, Marhall JTM-45. Thank you very much !
Thanks for your helpful input, Klaus. By coincidence on one of the schematics they show the pot, but add that "it is a nice alteration to the circuit". It really made biasing much easier.
I had to look up parsec ... Ha! Uncle Doug, you kill us! Love it. You make me want to acquire more amp knowledge than the difference between volume and attenuation.
Glad you enjoyed it, GT :)
Great tones. Even on my phone speakers. I'm sure it's a million times better in person. Great video
Thanks, Jason :)
Uncle Doug did I miss you!!!!!
Thanks !! We're glad to be back, Charles :)
Congrats on the silver UA-cam creator button!
Thanks, Tocsa. So far, YT hasn't told us it's "in the mail" :(
Great to see this british guy fixed. Even after watching you repair a lot of amps, your videos keep the high level of entertaining and informative like the first video.
Thanks so much, PoB :)
Your careful conservation and preservation versus someone's rapid repair. A beauty like this deserves nothing less. Spectabulous - as usual Sir!
Thanks, OL. Glad you liked it :)
Jack doing a good job of upstaging the amp repair with his "cat in a box" performance 😆
He's a gifted performer, Chris. I just stand back and let him steal the show :)
I love amps, but I'm not an electronics guy. 90% of the time I have no idea what UD is talking about, but these videos are so calming and stangely hypnotic...like watching Bob Ross paint.
Thanks, Ed. Bob and I appreciate your time and interest :)
Sir you are amazing God Bless your excellence in your work !
Thanks, LH :)
Hello Doug, both transformers should have part numbers stamped on them. Main is a 1202-55 and the output is 784-103. Great job and always a pleasure watching you work.
Thanks, Brian :)
It’s like I’m in a high school and I like the subject, but you’re the class after lunch and after 20 minutes I’m asleep. I’ve watched this four times now.
That's because we make you feel cozy and safe, David.
Your thorough on going technical trouble shooting proficiencies are astounding.
You are too kind, David. Thanks !!
You are the man, Doug. Good job.
Thanks, LB :)
Uncle Doug, so wise, lovely, humble and... so relaxing to watch. My favourite YT channel.
Thanks. Glad to hear it :)
Thank you for a great doubleheader video, Uncle Doug!
You're welcome, Hub.
Awesome, as always!
Thanks, MS :)
MacGyvering the Erie cap was total madness. Bravo.
Agreed, David, but trying new things makes life interesting :)
Yay! Uncle Doug is back!!
Great to be back, T&J :)
Really enjoyed watching this! Thanks UD
Our pleasure, Mick :)
Thanks for the video and especially the extra segment at the end!
Glad you enjoyed it, Daniel.
Man another killer sounding amp,.The P90’s were spectacular. sadly the only pedal steel I heard playing was only in my head. cheers
Thanks !! Our pedal steel player is in rehab, Kars. Maybe next video ;)
always enjoy watching and learn, thank you
Glad to hear it, Wally :)
Thank you uncle Doug!
YW, P ;)
Another great video as always thank you for showing us these awesome amps
It was a pleasure, Rob.
I don't know what he did, but the audio quality of Uncle Doug's videos has improved hugely. I used to watch him put together a beautiful old amp (and learn an enormous amount), then be really disappointed at the rattly, crunchy sound of the demo. No more! Maybe Jack and Ollie have sharpened up their chops!
Jack & Ollie are always at the top of their game, Vance, but your old Uncle has been upping the kbps and asr parameters in the audio processing program.
@@UncleDoug Thank you for that. It makes your videos even more of a pleasure to watch.
Love this channel 😎
....and we love our viewers, Marsh.
Very nice work Doug! The extra effort of installing the replacement cap inside the can is inspiring…
Thanks so much, Byron.
Yeah I like stuffing caps!
That was great, and it ended up sounding fantastic. Thanks for sharing.
Glad you enjoyed it, JL :)
Many thanks Doug for the wonderful video. As usual it's full of great advice. Your knowledge and humour are greatly appreciated.
That's great to hear, RN :)
Love the opening clip!
Thanks !! It was created by a very nice viewer.....from Poland, I believe.
Block end JTM45 chassis! Wow...I want one!
Apparently they are rather rare :) I hope you find one, Ireland.
Right on boss! What an amp! Thank you sir
Our pleasure, Scott. Thanks !!
Joy! He´s back!
Glad to be here, Aage :)
An excellent and relatively simple repair. Part two was very impressive! Thank you for taking the time to share your knowledge.
The pleasure was ours, Andrew. Thanks for watching.
new logo is nice! was not aware of it Uncle Doug. You have my utmost respect.
Thanks so much, Jose.
Another fantastic video. Thank you, Uncle Doug!
Glad you enjoyed it, Nick :)
Great episode, thank you!
Glad you enjoyed it, William.
Sorry ,I'm late. Very clean and comprehensive job, (As usual). Your customer should, be very HAPPY with it. Great video.
Thanks, RK. He is quite pleased :)