Here's that Max Pro Electronics Lubricant I showed at about 32:55 - amzn.to/2vZ62Y2 Compare that to the Deoxit: amzn.to/2Qcm0HT So far, it seems to be ok stuff. It definitely cleaned the pots and has an oily consistency like the Deoxit fader lube/cleaner. Thanks to whoever that was that suggested it.
My fave contact cleaner/lube right now. Amazon and Manufacturer page links. www.amazon.com/MG-Chemicals-Contact-Cleaner-Aerosol/dp/B001U3X3PA?th=1 www.mgchemicals.com/products/cleaning-products-for-electronics/cleaners/contact-cleaners/super-contact-cleaner-with-ppe-801b
@The Guitologist Are those the stock 500t and 496r that come in les paul classics? Sounds better than stock so I'm guessing you changed the pickups. What are they? What year is your classic it has a nice light burst.
Man when i was a teenager I would play my Peavy 5150 on our front porch so loud that my granny,who live about a quarter mile away could hear every note.Those were the days.I still occasionally blow out my ears in the bedroom.Combos are good but their is nothing like the sound of a half or full stack
@@TheGuitologist I live in a detached house, a good 70 yards from one neighbour, and the one on the other side is deaf. I have no fear in cranking up my JCM800 4212 in my house, as long as the windows are shut.
The volume of the amp is visible in your eyes, the way the lower lids come up to protect your delicate eyeballs from the face-melting sound pressure levels. Marshall Watts are louder than normal Watts.
Case in point: I have a JCM 800 50W 2 x 12 combo (4212). I used to play in a heavy metal band, and I never, ever had the master volume maxed out. My rhythm guitarist had a, 80W Valvestate hybrid amp, and even turned all the way up, it couldn't compete with my JCM800 with the master on 7.
I have a Super Lead and a Hiwatt DR-103, the Marshall is like a Fender Champ compared to the Hiwatt. Not that that’s a good thing, it’s just the way it is.
Now this is the reason I watch your channel. A diagnostic dilemma that finally gets resolved and then the rockin' demo. This and SPF are the foundations of your channel for me. Thanks Brad!!!
Man I really enjoy watching you figure shit out. Not sure why as I have no idea what you're doing but somehow it's enjoyable. Thanks Brad... Great video.
Brad, thanks for posting this amp, MY 1st Superlead amp also had times of red plating in V4 and V5 before I got it from the previous owner. When I get a block of time to devote 110% time to my amp diagnosing, I will be testing and referring back to this particular section where you address this in Jon's amp. I made it up to the point where you swapped tubes and the issue followed the tubes. I experienced blowing fuse issues from my amp the moment I got it home and fired it up. At first the 1A fuse blew as soon as I would put the standby into run position. Then upon replacing fuse and trying again, the Mains blew. Had to go to the store to get more fuses so with new ones and chassis removed from cab, a flash in V7 flashed bright, I heard a pop and once again the fuse would blow. This led to me fighting with the seller that he sold me amp with bad tubes and problems and should offer a partial or full refund. But he refused and claimed I did something to the amp to make it act this way. SOMEHOW he got the amp to run fine for me at his house, GOD knows how. Anyway, I am anxious to see you further test this. My amp still needs more things repaired than just the tubes, but I did get it to reliably run and not redplate or blow fuses after finding a local tube seller who I bought some TESTED GOOD Svetlana 6550's from. The seller even had me bring my amp to him to test ALL the tubes I got from the previous owner. Long story short, The tube from V7 was so bad it shut his tester down to protect itself and 6 of the 7 tubes in the amp tested bad or weak. He threw in 3 12 ax7's from his stock along with the 6550's I bought from him. He had 40+ years in the car audio industry and is a terrific audiophonics resource. Thanks again Brad, I will hopefully have updates as well as I delve into my PCB version of Jon's amp.
I've zero experience about those capacitors or smt and ain't planning to buy or repair that kind of amp but I've watched every second of it like it was some kind of magic. Thank you!
the way i describe my 71 super lead 100 is 'explosive' i got mine around 82, plugged it in, pagged it and...oh my gawd! just the best ever and like a cannon going off
Bore me, Bore ME. Also, thanks for this video and your others. As I make my way through my 50's I am reaping the tremendous teachings like yours on video. I have also been blessed with meeting friends online all over the world who teach me electronics and explain my questions. My childhood fear of not being able to comprehend or retain the info has now gone by the wayside as I have learned schematics and amp design, test procedures, and put into practice how to service amps my friends' amps and my own.
Saw the previous video and followed where you got to the point of "nothing else left to replace!" and got the rewards! Nice comprehensive fix. Sometimes you just have to go to that extent of repair. Now should last for years! Well done!
Jon: BRAD, THANK YOU THANK YOU THANK YOU, SIR...your perseverance and expertise has given my 71 a new lease on life! I can’t wait to get her back....piss off my neighbors... Brad: Huh? What? Wha did you say?!? Seriously, thank you. I have another job for you, if interested. Your mission, Mr. Phelps, should you decide to take it: a 1980 Marshall Master Lead 100w that was converted to 6CA7s. The bias cannot be set within operational range, it runs too cold. Can you change the tubes back to stock (6550s or EL34s)? This comment will self-destruct in 5 seconds...
5 words... Post Phase Inverter Master Volume. I put one in my home brew 1959 clone. Very playable and still crunchy as hell. I find it better than the 800 style MV. You get to drive the PI harder without melting your face. Less buzzy than the 800. One down side is that the presence control become less effective at lower volumes because of less negative feedback.
I have the same amp, even same year, for a few months, and yeah, get this overdrive is so loud. I still didnt get it in fact. Waiting to go to some studio or open air to go up into the volume pots! Its a lovely amp and I was playing with a lap steel. Finally I repaired yesterday my old strat and played today and they sound sooooo amazing!!!
My 50 watt Lead Series can not be turned up more than 3, on the preamp vol. with the Master vol. at 10! Can not imagine how loud this amp is! Great service on this one Brad! You always deliver! Thanxz
Audio Tech Labs I have one too (a 50W 2 x 12 JCM800 4212 combo), and I routinely have the preamp on 11, it's the master volume I can't turn past 5 without risking blowing the windows and my eardrums out.
I had an amp come back to me 4 times. The owner was complaining that it would all of a sudden start crackling. I went over everything, took a heat gun to it, sprayed it with freeze mist. Bump & banged the tubes, banged on the whole amp. Picked it up a few inches & dropped it. Problem would not manifest itself on the bench. The 4th time it came back, I tapped against the tubes with a different screw driver that I usually don't use for audio/video work. I approached one tube in particular with this screw driver I could get the amp to cut out, just in one spot. This screw driver was magnetized. It was a broken spot weld somewhere inside the tube.
My uncle who was a gigging musician is the 70s , gave me a Traynor 200 watt ,amplifier. It had a cabinet with four 15 “ speakers , and a head that sat on top of speaker cabinet. It was a “Beast” and would give any Marshal Stack a run for its money. it was friking loud, and sounded awesome.
Got a ~1968/9 plexi head 29 years ago which I still have. Put some nice caps and resistors in and it sounds terrific. Only use two output tubes and it's still LOUD. But marvelously so. Had a full metal panel stack in the late 70s but traded it off. Love plugging straight into an old Super Lead and cranking it.
Brilliant work TG. You have to love a playing tech. Knows what the gear is supposed to sound like and how to make the electrical love move right to get there.
Glad to see you did what most of techs do and remove those underboard can caps from the top. You had me worried there for a while talking about removing the board.
i had a very strong superlead a few years ago,i walked around the house while my teacher played it,an he admitted it hurt him also, but a beautiful rich sound...
I have a 1971 Super Bass Head with the lead mod switch done by Marshall. Its essentially the same amp but mine has bakelite sockets. Funny story: In 1971 the original owner played it in the shop for an hour, go it home, played it for 5 mins and his wife ordered it out of the house. In the following week, he got promoted at work, his band split up and his wife discovered she was pregnant! So in 1986 he sold it to us for £99. Back when rack gear was all the rage, none wanted big heads like this.
Thanks, I don’t know why but that made my day.and the gold top Les Paul was the perfect guitar to test it with. Like they were meant to be with each other.
Man, does this one ever take me back! My first Air Force assignment in the ATC Radar career field was to Hurlburt Field, with an ancient, 50s-era MPN-13 all-tube radar set. Troubleshooting went more or less exactly like this, with the occasional tube socket replacement. Most of us dreaded those, as every pin had any number of components wired and directly connected to them. I miss that job.
It was, mostly. The only time it wasn't fun was when your radar was off the air with a very hard to chase down trouble. It was an air traffic control radar, and when it goes down, you have to send a NOTAM (Notice To Airmen) to the FAA, and then everybody in the chain of command is breathing down your neck. Heh, they seem to forget that spending all your time on the phone prevents repair LoL. But yeah, mostly it was great fun, which is why I miss it. All of the mobile radars went to Desert Storm and probably never came back. That's sad.
I was a squid ( navy) Et ( extra testicles) I miss all of the really great old tube stuff. [ sniff] thx for your service. Millions of watts, what could go wrong??????
Lee James thanks for YOUR service, man. My trainer right out of tech school was former Navy, and he's the reason I became the technician I did. IDK about now, but back in his day they didn't teach sailors different types of electronic systems, like radar, radio, AC&W, ILS, etc. They just taught them electronics, and when you got to your ship, you studied the theory of operation of whatever was broken, and fixed it. I feel like others got cheated, and I lucked out.
@@jamesthe-doctor8981 we were actually called " everything " techs. Almost went blind going through the school ,physics and math and theory 50% of grade based on labs....real radars and radio equipment. About a year of hell, messed with you any way they could. To make sure you could handle anything that might come your way on board the ship. After the school, you KNEW you could handle anything!!! Did it for about a decade then, got out. WHAT A RIDE!
The easiest way to discharge them safely is to use a multimeter with a low impedance mode (LowZ). Just put one probe on each terminal and it will drain off in just a few seconds, but you are limited by whatever max voltage the meter can handle. Another alternative is to build a "dead man's stick", see here - th-cam.com/video/gLDCV-n1BDw/w-d-xo.html
Hey Hey and Holy Cow! I clicked because of the Cub's jersey but stayed to watch the trouble shooting and repair. Great job and love that tone, just plug in a play.
I recapped and went through a 1970 metal face Marshall Major for my friend and we played it through both cabinets with gun muffs on to try it out. I remember that it had 600v B+. Cute woven asbestos keeper hats for the KT88s too. It was rural so nobody could hear it. Physical air movement that vibrated your entire skeletal structure. I went outside while he was playing and his windows rattled violently on resonant notes. His little house took a beating THAT night. I am surprised that Ritchie Blackmore is not deaf from humping his Marshall Major all those nights while it fed back in his face....
What's even more insane, is that Blackmore had his Majors modded to have an additional pair of output tubes. So yeah, you want to talk about bone rattling sound pressure levels lol
Great job Brad. I hate when gremlins get in my electronic that I'm servicing. You have lots of paients !!!!! You are very honest to show what occurs when gremlins get loose in a job you are servicing for all the world to see. Thanks Brad !!!!!! Good Job !!!!!! Ricky from IBM
Hey Brad that happened to me when I put new ones in my epi senior amp . This amp has a sell bal. too . Sent them back they sent new ones and no problem. Love your vids.
Great job! There is NOTHING like the sound and feel of a well tuned vintage Marshall tube amp!!! P.S., I have had very good results using the tiny airbrush cleaning brushes ( found at that store where you got the heat shrink tubing) for cleaning small openings, like those tube sockets!
Makes me remember when the fusses were the most important bits in our tool kit. We traveled with a Marshall 50w, 2 100W Marshall Supers, and one 200w beast! Cold solder joints were a real bear! This was in the mid '70's, so my memory lacks some.
Great video. I learn at least two or three things from every video of yours. And i claim to know a little about amps. Your videos are like crack to an amp geek. I want more and more. That’s why I’ve started going back over your old videos. That way i can catch anything i might have missed.
I've owned a few of those model 1959 S/L amps. Never got the volume past 2 in the shop because stuff would just start falling off the walls. They do have an amazing clean sound.
Tonal Perfection all around sweet spot. I owned one a long time ago and it was modded with a master volume installed in the bottom left input jack space.
The Tone! It is good to see the Marshall back in service and be reliable and dependable. The demo jam at the end was also pretty tasty. A word to the EL34. I used the Electro Harmonix EL34s throughout several amps for many years (even one with 2 EL34s and a Plate voltage of approx. 800V) and never experienced any electrical issues. I switched to JJs only for tonal reasons (the EL34EH are way to aggressive in an ENGL Powerball I). Also The 6CA7EH seems to be discontinued are pretty hard to come by. EHs aswell as JJs are bulletproof and a good choice for most amps IMHO. Keep up the great work, Brad!
That amp has gorgeous cleans. And I'm sure it has plenty of headroom, too. Only issue is that they are so even across dynamics that you just can't hear how loud they are through computer speakers. Same for mesas. If you can turn a 50 watt mesa amp way up and sit in front of it, you're a real man. A deaf one. A real deaf one!
Yeah, there's just no way to really impart how loud amps are in a video. The compression and cascaded gains on the mixer make it seem actually quiet. But seriously, I was cringing the entire time sitting beside this thing, even doing the clean sections.
Interesting video Brad. As has been said, the symptoms would seem to indicate parasitic oscillations. Presumably, the 5.6K grid stoppers are fitted underneath the tag board. It is best to mount one end of the grid stopper resistor (non inductive type) directly to the tube grid pin on the valve base, using a resistor self-lead as short as possible. Also, it is best to use one grid stopper per tube. (sometimes Marshall fitted one grid stopper shared between two in-phase tubes). (England)
G- man haven't made many comments on your marshall vids before because you seem to be well knowledgeable than others on this subject , I have a 1977 2204 MK2 master Model 100w lead double stack in a fawn color tolex(no mods) that is do-n the same thing as the 71 you worked on, I am considering putting it on market but not in this state its in , this amp was purchased from a 1 owner who bought it brand new in 77, his brother who was the bass player for the band I was in before there was dirt, told me in 2002, his older bro had a orange colored Marshall that he couldn't use anymore due to a back injury he got from work, this happened 2 years after he bought the amp, he didn't want to get rid of the amp so he put it in storage think-n he would recover from his ailment , needless to say it sat for another 27 or so years until I saved it from disintegration, Well after i became owner I took it to a tech here in Florence Ky. to have all new tubes throughout / new caps and an overall checkup , when i looked at it for the first time and fired it up ! it sounded like a lightning storm go-n on in the head , that gave me the grounds to hit him with a lower price , I then took it to a tech to installed the new tubes but I don't think he cleaned the socket's ,so I cleaned them and pinched the terminals tighter myself I knew enough to discharge the caps but that was my limit still don't know if that cleaning help matters, the tubes are JJ - 6550s and two of them still have no sings of work-n, the JJ lettering color still looks brand new while the other two show signs of darkening ? my point is I'm try-n to see what does one have to do to Get you to look it over and make a new vid out of this mystery ? Oh! sorry bout the novel I've made here and my text typing (The Hippie with Hair )
My dad had one of these in the from the late 80's to mid 80's. No polarity deletes so it was dangerous and She was problematic, but oh the output! A true beast! He traded for a JCM800 in '99-2002(ish). Something he regrets til this day..
I use to have a 2×12 version of this same amp( Super Lead 100) back in 1982/83? Bought it used for$550, then I traded for a Peavey Special 130( wish I didn't do that !!! Love the Cubs shirt( being originally from Chicago, now living in N Ft Myers Florida). Great video bro!!!
Great video series on this Marshall Super lead repair. You are a true problem solver! (I did not see the Mesa Boogie series you refereed to but in past videos I have heard you talk about it.)
I have a Marshall JCM800 4212 50W combo that I have owned from new. In my old metal band, the rhythm guitarist had a 75W Valvestate. However, even flat out, he couldn't drown out my amp with the master volume set to 7. It's amazing how tough these old amps are. I gigged the JCM for fifteen years, and it looked a real mess, but still rocked night after night. I live in SE England, about an hour down the road from Marshall Amplification. So a couple of years ago, I decided to give "Marsha" a birthday at the place where she was born. I wanted new feet, new Tolex, new fret cloth, a re-cap and re-valve, and replacement of broken pots and missing knobs. I was OK with the price - very reasonable considering the labour - but blanched when they told me the cost of replacing the original Marshall logo. However, when I said I'd have to leave that repair out, the guy leaned forward and snapped the logo in half, saying, "Whoops, my fault. So we'll pay for the logo." Amazing. The one thing Marshall couldn't replace was the "50W Lead" label, but I found someone on eBay who had laser-etched replacements on real brass instead of brass-coloured plastic. Now, bar some battle scars on the control plate, she looks and sounds good as new. And as loud as ever.
"Clip and re-strip" hey now ! lol. Thanks for the video, i have never worked on an older Marshall like this so this was a new thing for me to check out. Oldest Marshall ive worked on was a mid 80s JCM 800.
Love the look on your face when you first started playing. Looked like you were trying to keep your head from blowing off of your shoulders. I suppose that says everything there is to say about how loud that 100 Watt Marshall is..... Great video.
Nice pair of videos fixing this classic rock machine! I am impressed by your ability to diagnose the tube socket problem along with a power tube problem. That sucks when new parts have an issue. But a '71 Marshall Super Lead is an amp worth putting some money into to keep in top shape.
OK, solid state comment: I have a friend who can not and does not play. Back in the early 70's he was a contractor and agreed to be paid off with a '71 double bound, three color burst, one piece maple neck telecaster and an "Acoustic Instruments 150" head with half stack 4x12 cab. He dragged this stuff up and down the east coast for a couple of decades every time he moved, then put the amp into storage until he decided to lighten his load and gave me the amp. He still has the mint condition Tele in the original HSC. I had to replace two of the speaker coil covers from damage during one of his moves and replace the two prong power cord with a grounded one after my son was almost electrocuted plugging his Tele into it while standing barefoot on the garage floor. Then, I plugged it in, dimed everything and decided to check it out using my L.P. Jr. and a version of Mississippi Queen and a few other classic riffs until it set off home and car alarms and naturally the police showed up in about ten minutes trying to tell me something about disturbing the peace. But, my ears were ringing so much I could hardly hear what he was saying. I knew he wanted me to stop just from a common sense point of view. I did a little research on these Acoustic Instruments amps and found they were one of the early first solid state amp that were used by some famous name groups and musicians. Santana were using these amps at Woodstock '69. You can see this in the movie. There is a forum online devoted to these amps. They were fucking loud. I had no room to keep it so I put it up for sale on CL. It sold in two days. People were desperate for anything from these amps. Especially the aluminum handles for the vol, tone etc. These amps were not the same as the GC Acoustic brand of amps. They were advertised as loud and clean. Though they did have a dirty channel. I think the next higher in power were the 360 models. The 150 models were supposed to put out a screaming 150 watts of power. The beauty of these amps was that they were modular. They had circuit boards that could be replaced almost on the fly. I guess Brad could troubleshoot and repair the circuit boards after another was just plugged in and re-use the repaired one. But this company was ahead of its time. For some reason they closed up shop and sold the name to GC, whose amps by that name really sucked.
Sounds fantastic! I have a 1987X Plexi reissue 50 watt, and it's frigging loud too. I can only imagine the decibels on that 100 watt Super Lead. I never play it without a Weber Mass 50 attenuator, to calm the beast down.
Enjoyed the vid. I love working or building tube amps. Built a 50 watt 1987 which I'm going to change to bass 1986 spec and then start a JTM45 for which I have NOS GEC KT66 and Mullard 12AX7's.
you should try some winged =C= EL34s - they sound awesome to me, especially on high gain. The JJs seem to have a great low end though which is nice for clean.
@@mutarerrs I liked the original "Svetlana winged C" for amps like DSL's that are supposed to have a clean. I haven't cared personally for the Reflektor made Svetlanas, and while I did like the later "=C=" tubes, which were made by the original people that did the first Svetlana tubes, they were either out of production or something else happened, that they started going for stupid prices.
yes - i have a DSL, great call - and i just paid about $85 each for a matched pair of NOS =C=. The JJs are just fine too but the real magic is in my RCA 12AX7 preamp tubes. Haven't tried any mullards yet - def will at some point.
Nice job Brad! Sometimes you gotta dig deep to find multiple issues and get them lined out. I can't even imagine how loud that damn thing is.🤪 My Peavey Bandit 65 with a 10 in. Black Widow speaker is and was more than enough for any gig I ever did! It's now relegated to just occasional home use, and can be turned way down so as not to piss off the neighbors.😆
Good job Brad! The clean sound on that amp is really nice. I think you and the customer were right to replace the caps and tubes. The crud in those sockets was not nice! Congratulations on persevering with a difficult diagnostic problem or set of problems!
I will never forget my first KISS concert in the early 70's. I was on the floor along with a thousand or so more, close to the stage. 20 minutes in I had to go for a piss. I get to the can & immediately notice that my ears are ringing, really bad. Left the can & went home.
I had a 71 SL 20some years back. Not having good tech near me, and with my electronics experience I braved changing my caps. Was the start of a fairly decent amp business for a few years... anyways, how you replaced the under board filter cap is exactly how I did it, as well as how most that I know do it. Nice amps, though, but definitely need attenuation lol
@30:42 GUM dental scrubbers. *Fantastic* tip. I've been using those for cleaning air passages and metering orifices on weed-eater, lawn mower and old auto carburetors for a few years now. They even have different sizes and bristle stiffness.
JJ Can capacitors are a good replacement choice. I got the same issue with red glowing power tubes, when my Phase Inverter cathodes were weirdly connected to B+ and it took me few hours to find what went wrong. In my case, the bias supply was simply bypassed. My mistake was to put some hot glue to prevent the components to move. It's not the best way to go if you want to mod your amp or fix an issue.
Around 1980 I sold my 1971 Hiwatt100 and bought a 1968 100W 'plexi' Super Lead , holy shit that was the loudest amp I ever heard, too loud for most of the gigs I was doing at the time, people in the audience would duck when I keranged an E! happy days...
Here's that Max Pro Electronics Lubricant I showed at about 32:55 - amzn.to/2vZ62Y2
Compare that to the Deoxit: amzn.to/2Qcm0HT
So far, it seems to be ok stuff. It definitely cleaned the pots and has an oily consistency like the Deoxit fader lube/cleaner. Thanks to whoever that was that suggested it.
HUH?...WHAT?....no I don’t know where Darth Vader makes his deposits....lol, excellent work Brad, can’t beat a Les Paul through a Marshall.
My fave contact cleaner/lube right now. Amazon and Manufacturer page links. www.amazon.com/MG-Chemicals-Contact-Cleaner-Aerosol/dp/B001U3X3PA?th=1 www.mgchemicals.com/products/cleaning-products-for-electronics/cleaners/contact-cleaners/super-contact-cleaner-with-ppe-801b
Nice thick crunchy tone! It's a Marshall it gets fucking loud!
@The Guitologist Are those the stock 500t and 496r that come in les paul classics? Sounds better than stock so I'm guessing you changed the pickups. What are they? What year is your classic it has a nice light burst.
The pickups are not stock, they are "59 PAF Reissues". Killer pickups.
Didn’t need reverb on those amps. The reverb from the stadium was perfect.
Ive got a couple stadiums lying around, great reverb.
Neighbors come and go, but a good ole Black Sabbath riff on a Marshall super lead is forever
And often it's the reason neighbors go. :D
Probably caused some waves out there in the universe I'm sure ☺
Man when i was a teenager I would play my Peavy 5150 on our front porch so loud that my granny,who live about a quarter mile away could hear every note.Those were the days.I still occasionally blow out my ears in the bedroom.Combos are good but their is nothing like the sound of a half or full stack
@@TheGuitologist I live in a detached house, a good 70 yards from one neighbour, and the one on the other side is deaf. I have no fear in cranking up my JCM800 4212 in my house, as long as the windows are shut.
That would be a Laney Supergroup...
Now you know why Johan Segeborn always has his muffs on in the amp room 😂
You can clearly see the pain in your eyes while playing. :D
@@kellyjackson7889 I like to think hes listening to audio books
No shit.
Muffs is cheating..
The volume of the amp is visible in your eyes, the way the lower lids come up to protect your delicate eyeballs from the face-melting sound pressure levels. Marshall Watts are louder than normal Watts.
Case in point: I have a JCM 800 50W 2 x 12 combo (4212). I used to play in a heavy metal band, and I never, ever had the master volume maxed out. My rhythm guitarist had a, 80W Valvestate hybrid amp, and even turned all the way up, it couldn't compete with my JCM800 with the master on 7.
22222222 ES 260, , , , , , , AA
@@Dragonblaster1 I was the valvestate kid in my band :(
I always maxed the volume and used pedals to boost and it still was never satisfying
Ohms law is always ohms law.
I have a Super Lead and a Hiwatt DR-103, the Marshall is like a Fender Champ compared to the Hiwatt. Not that that’s a good thing, it’s just the way it is.
I was born in '71 and my dream is to own a '71 Marshall head. I'd be stoked to own this amp.
I'm literally on the edge of my seat with this bias mystery.
Now this is the reason I watch your channel. A diagnostic dilemma that finally gets resolved and then the rockin' demo. This and SPF are the foundations of your channel for me. Thanks Brad!!!
I'm excited and half finished
Man I really enjoy watching you figure shit out. Not sure why as I have no idea what you're doing but somehow it's enjoyable. Thanks Brad... Great video.
That was thee coveted amp of its time we were in awe of it as teenagers in the 70's
Brad, thanks for posting this amp, MY 1st Superlead amp also had times of red plating in V4 and V5 before I got it from the previous owner. When I get a block of time to devote 110% time to my amp diagnosing, I will be testing and referring back to this particular section where you address this in Jon's amp.
I made it up to the point where you swapped tubes and the issue followed the tubes. I experienced blowing fuse issues from my amp the moment I got it home and fired it up. At first the 1A fuse blew as soon as I would put the standby into run position. Then upon replacing fuse and trying again, the Mains blew. Had to go to the store to get more fuses so with new ones and chassis removed from cab, a flash in V7 flashed bright, I heard a pop and once again the fuse would blow.
This led to me fighting with the seller that he sold me amp with bad tubes and problems and should offer a partial or full refund. But he refused and claimed I did something to the amp to make it act this way. SOMEHOW he got the amp to run fine for me at his house, GOD knows how. Anyway, I am anxious to see you further test this. My amp still needs more things repaired than just the tubes, but I did get it to reliably run and not redplate or blow fuses after finding a local tube seller who I bought some TESTED GOOD Svetlana 6550's from. The seller even had me bring my amp to him to test ALL the tubes I got from the previous owner. Long story short, The tube from V7 was so bad it shut his tester down to protect itself and 6 of the 7 tubes in the amp tested bad or weak. He threw in 3 12 ax7's from his stock along with the 6550's I bought from him. He had 40+ years in the car audio industry and is a terrific audiophonics resource. Thanks again Brad, I will hopefully have updates as well as I delve into my PCB version of Jon's amp.
Dammmnnn that Marshall tone is timeless. Awesome repair on a kickass amp.
I've zero experience about those capacitors or smt and ain't planning to buy or repair that kind of amp but I've watched every second of it like it was some kind of magic. Thank you!
the way i describe my 71 super lead 100 is 'explosive' i got mine around 82, plugged it in, pagged it and...oh my gawd! just the best ever and like a cannon going off
Bore me, Bore ME. Also, thanks for this video and your others. As I make my way through my 50's I am reaping the tremendous teachings like yours on video. I have also been blessed with meeting friends online all over the world who teach me electronics and explain my questions. My childhood fear of not being able to comprehend or retain the info has now gone by the wayside as I have learned schematics and amp design, test procedures, and put into practice how to service amps my friends' amps and my own.
Saw the previous video and followed where you got to the point of "nothing else left to replace!" and got the rewards! Nice comprehensive fix. Sometimes you just have to go to that extent of repair. Now should last for years! Well done!
Jon: BRAD, THANK YOU THANK YOU THANK YOU, SIR...your perseverance and expertise has given my 71 a new lease on life! I can’t wait to get her back....piss off my neighbors...
Brad: Huh? What? Wha did you say?!?
Seriously, thank you. I have another job for you, if interested. Your mission, Mr. Phelps, should you decide to take it: a 1980 Marshall Master Lead 100w that was converted to 6CA7s. The bias cannot be set within operational range, it runs too cold. Can you change the tubes back to stock (6550s or EL34s)? This comment will self-destruct in 5 seconds...
I'll message you a bit later with details!
5 words... Post Phase Inverter Master Volume. I put one in my home brew 1959 clone. Very playable and still crunchy as hell. I find it better than the 800 style MV. You get to drive the PI harder without melting your face. Less buzzy than the 800. One down side is that the presence control become less effective at lower volumes because of less negative feedback.
Sounds awesome dude....like the old days... when I was a. Teenager....I just turned 68..…still love my Marshalls and les pauls...
What a GREAT trick for changing that filter cap that's concealed by the board. Thank you :)
I have the same amp, even same year, for a few months, and yeah, get this overdrive is so loud. I still didnt get it in fact. Waiting to go to some studio or open air to go up into the volume pots!
Its a lovely amp and I was playing with a lap steel. Finally I repaired yesterday my old strat and played today and they sound sooooo amazing!!!
You the magic Marshall doctor...much love and respect to you good brother...
My 50 watt Lead Series can not be turned up more than 3, on the preamp vol. with the Master vol. at 10! Can not imagine how loud this amp is! Great service on this one Brad! You always deliver! Thanxz
Audio Tech Labs I have one too (a 50W 2 x 12 JCM800 4212 combo), and I routinely have the preamp on 11, it's the master volume I can't turn past 5 without risking blowing the windows and my eardrums out.
I had an amp come back to me 4 times. The owner was complaining that it would all of a sudden start crackling. I went over everything, took a heat gun to it, sprayed it with freeze mist. Bump & banged the tubes, banged on the whole amp. Picked it up a few inches & dropped it. Problem would not manifest itself on the bench. The 4th time it came back, I tapped against the tubes with a different screw driver that I usually don't use for audio/video work. I approached one tube in particular with this screw driver I could get the amp to cut out, just in one spot. This screw driver was magnetized. It was a broken spot weld somewhere inside the tube.
Thanks for sharing -
You need to play more on here man.
I've replayed the last few minutes of this video over and over.
It's so good!
I had one of these. My fave amp EVER. Jaysus they sounded good.
I'm glad you have some Gibson sounds going. Like the Tele too. The Marshall sounds really great. Fantastic work.
My uncle who was a gigging musician is the 70s , gave me a Traynor 200 watt ,amplifier. It had a cabinet with four 15 “ speakers , and a head that sat on top of speaker cabinet. It was a “Beast” and would give any Marshal Stack a run for its money. it was friking loud, and sounded awesome.
Got a ~1968/9 plexi head 29 years ago which I still have. Put some nice caps and resistors in and it sounds terrific. Only use two output tubes and it's still LOUD. But marvelously so. Had a full metal panel stack in the late 70s but traded it off. Love plugging straight into an old Super Lead and cranking it.
Brilliant work TG. You have to love a playing tech. Knows what the gear is supposed to sound like and how to make the electrical love move right to get there.
Thanks man! I appreciate you watching.
Glad to see you did what most of techs do and remove those underboard can caps from the top. You had me worried there for a while talking about removing the board.
i had a very strong superlead a few years ago,i walked around the house while my teacher played it,an he admitted it hurt him also, but a beautiful rich sound...
Thats's the sound of Rock and Roll right there. Get sum, Brad
I have a 1971 Super Bass Head with the lead mod switch done by Marshall. Its essentially the same amp but mine has bakelite sockets.
Funny story: In 1971 the original owner played it in the shop for an hour, go it home, played it for 5 mins and his wife ordered it out of the house. In the following week, he got promoted at work, his band split up and his wife discovered she was pregnant! So in 1986 he sold it to us for £99. Back when rack gear was all the rage, none wanted big heads like this.
Thanks, I don’t know why but that made my day.and the gold top Les Paul was the perfect guitar to test it with. Like they were meant to be with each other.
the tone on that thing is something else. wow
Since watching your channel, I get cool engineering videos. Thanks for the algorithm setup.
Apparently people love Marshall vids, nice job Brad
Man, does this one ever take me back! My first Air Force assignment in the ATC Radar career field was to Hurlburt Field, with an ancient, 50s-era MPN-13 all-tube radar set. Troubleshooting went more or less exactly like this, with the occasional tube socket replacement. Most of us dreaded those, as every pin had any number of components wired and directly connected to them. I miss that job.
James TheDoctor Duncan sounds like fun, actually.
It was, mostly. The only time it wasn't fun was when your radar was off the air with a very hard to chase down trouble. It was an air traffic control radar, and when it goes down, you have to send a NOTAM (Notice To Airmen) to the FAA, and then everybody in the chain of command is breathing down your neck. Heh, they seem to forget that spending all your time on the phone prevents repair LoL. But yeah, mostly it was great fun, which is why I miss it. All of the mobile radars went to Desert Storm and probably never came back. That's sad.
I was a squid ( navy) Et ( extra testicles) I miss all of the really great old tube stuff.
[ sniff] thx for your service.
Millions of watts, what could go wrong??????
Lee James thanks for YOUR service, man. My trainer right out of tech school was former Navy, and he's the reason I became the technician I did. IDK about now, but back in his day they didn't teach sailors different types of electronic systems, like radar, radio, AC&W, ILS, etc. They just taught them electronics, and when you got to your ship, you studied the theory of operation of whatever was broken, and fixed it. I feel like others got cheated, and I lucked out.
@@jamesthe-doctor8981 we were actually called " everything " techs. Almost went blind going through the school ,physics and math and theory 50% of grade based on labs....real radars and radio equipment. About a year of hell, messed with you any way they could. To make sure you could handle anything that might come your way on board the ship.
After the school, you KNEW you could handle anything!!!
Did it for about a decade then, got out. WHAT A RIDE!
Love your vids!!! Please do one on safely discharging caps!!! Rock on Brother!!!
Timidater Absolutely this!
The easiest way to discharge them safely is to use a multimeter with a low impedance mode (LowZ). Just put one probe on each terminal and it will drain off in just a few seconds, but you are limited by whatever max voltage the meter can handle. Another alternative is to build a "dead man's stick", see here - th-cam.com/video/gLDCV-n1BDw/w-d-xo.html
Hey Hey and Holy Cow! I clicked because of the Cub's jersey but stayed to watch the trouble shooting and repair. Great job and love that tone, just plug in a play.
Not enough watts! Great video! And GOOD you found the reason! In the end Marshall used several different tube sockets! WOW! You can't trust anyone!
I recapped and went through a 1970 metal face Marshall Major for my friend and we played it through both cabinets with gun muffs on to try it out. I remember that it had 600v B+. Cute woven asbestos keeper hats for the KT88s too. It was rural so nobody could hear it. Physical air movement that vibrated your entire skeletal structure. I went outside while he was playing and his windows rattled violently on resonant notes. His little house took a beating THAT night. I am surprised that Ritchie Blackmore is not deaf from humping his Marshall Major all those nights while it fed back in his face....
I honestly can't imagine. It's like grabbing the reigns of a wild stallion and holding on for dear life.
What's even more insane, is that Blackmore had his Majors modded to have an additional pair of output tubes. So yeah, you want to talk about bone rattling sound pressure levels lol
IT'S ALIVE! And sounds great. With strat sounds amazing! Also always nice to see that fixer can play too.
I heard the right thing from my end. God bless your time spent.
Great job Brad. I hate when gremlins get in my electronic that I'm servicing.
You have lots of paients !!!!!
You are very honest to show what occurs when gremlins get loose in a job you are servicing for all the world to see.
Thanks Brad !!!!!!
Good Job !!!!!!
Ricky from IBM
Hey Brad that happened to me when I put new ones in my epi senior amp . This amp has a sell bal. too . Sent them back they sent new ones and no problem. Love your vids.
I just had to watch the end of this again at 43:00. Epic moment Brad!
If you add a condensor mic about a foot back and up, and blend them, you will get just a huge sound. Also, go Cubs!
Excellent work Brad. I watched the first installment. This second installment wrapped it up.
Great job! There is NOTHING like the sound and feel of a well tuned vintage Marshall tube amp!!! P.S., I have had very good results using the tiny airbrush cleaning brushes ( found at that store where you got the heat shrink tubing) for cleaning small openings, like those tube sockets!
Makes me remember when the fusses were the most important bits in our tool kit. We traveled with a Marshall 50w, 2 100W Marshall Supers, and one 200w beast! Cold solder joints were a real bear! This was in the mid '70's, so my memory lacks some.
Love those old Marshalls.They even look loud.
Great video. I learn at least two or three things from every video of yours. And i claim to know a little about amps. Your videos are like crack to an amp geek. I want more and more. That’s why I’ve started going back over your old videos. That way i can catch anything i might have missed.
I've owned a few of those model 1959 S/L amps. Never got the volume past 2 in the shop because stuff would just start falling off the walls. They do have an amazing clean sound.
I subbed because you installed the wrong "tone" batteries on Will's grandfather's amp.
Tonal Perfection all around sweet spot. I owned one a long time ago and it was modded with a master volume installed in the bottom left input jack space.
This was cool. I havent watched any videos like this since the Mesa vid but I was able to follow this one a bit for someone as clueless as myself.
WOW, those cleans are amazing very beautiful.
The Tone! It is good to see the Marshall back in service and be reliable and dependable. The demo jam at the end was also pretty tasty. A word to the EL34. I used the Electro Harmonix EL34s throughout several amps for many years (even one with 2 EL34s and a Plate voltage of approx. 800V) and never experienced any electrical issues. I switched to JJs only for tonal reasons (the EL34EH are way to aggressive in an ENGL Powerball I). Also The 6CA7EH seems to be discontinued are pretty hard to come by. EHs aswell as JJs are bulletproof and a good choice for most amps IMHO. Keep up the great work, Brad!
tubedepot.com sells the 6CA7EH still. I've got a pair from them that I've used in a VHT 50/CL and they're awesome!
That amp has gorgeous cleans. And I'm sure it has plenty of headroom, too.
Only issue is that they are so even across dynamics that you just can't hear how loud they are through computer speakers. Same for mesas. If you can turn a 50 watt mesa amp way up and sit in front of it, you're a real man.
A deaf one. A real deaf one!
Yeah, there's just no way to really impart how loud amps are in a video. The compression and cascaded gains on the mixer make it seem actually quiet. But seriously, I was cringing the entire time sitting beside this thing, even doing the clean sections.
What?
Ear plugs are gonna come
in handy.
I have a Blackstar HT 60 that I run through a 4x12 vintage 30's and Man I cranked it to noon and 🤯, it's soo loud!
Interesting video Brad. As has been said, the symptoms would seem to indicate parasitic oscillations. Presumably, the 5.6K grid stoppers are fitted underneath the tag board. It is best to mount one end of the grid stopper resistor (non inductive type) directly to the tube grid pin on the valve base, using a resistor self-lead as short as possible. Also, it is best to use one grid stopper per tube. (sometimes Marshall fitted one grid stopper shared between two in-phase tubes). (England)
G- man haven't made many comments on your marshall vids before because you seem to be well knowledgeable than others on this subject , I have a 1977 2204 MK2 master Model 100w lead double stack in a fawn color tolex(no mods) that is do-n the same thing as the 71 you worked on, I am considering putting it on market but not in this state its in , this amp was purchased from a 1 owner who bought it brand new in 77, his brother who was the bass player for the band I was in before there was dirt, told me in 2002, his older bro had a orange colored Marshall that he couldn't use anymore due to a back injury he got from work, this happened 2 years after he bought the amp, he didn't want to get rid of the amp so he put it in storage think-n he would recover from his ailment , needless to say it sat for another 27 or so years until I saved it from disintegration, Well after i became owner I took it to a tech here in Florence Ky. to have all new tubes throughout / new caps and an overall checkup , when i looked at it for the first time and fired it up ! it sounded like a lightning storm go-n on in the head , that gave me the grounds to hit him with a lower price , I then took it to a tech to installed the new tubes but I don't think he cleaned the socket's ,so I cleaned them and pinched the terminals tighter myself I knew enough to discharge the caps but that was my limit still don't know if that cleaning help matters, the tubes are JJ - 6550s and two of them still have no sings of work-n, the JJ lettering color still looks brand new while the other two show signs of darkening ? my point is I'm try-n to see what does one have to do to Get you to look it over and make a new vid out of this mystery ? Oh! sorry bout the novel I've made here and my text typing (The Hippie with Hair )
The T-REX of TONE, imitated ,but NEVER DUPLICATED, GOD BLESS OL' JIM MARSHALL.
My dad had one of these in the from the late 80's to mid 80's. No polarity deletes so it was dangerous and She was problematic, but oh the output! A true beast! He traded for a JCM800 in '99-2002(ish). Something he regrets til this day..
Finally got it sorted out. Good job Brad.
I use to have a 2×12 version of this same amp( Super Lead 100) back in 1982/83? Bought it used for$550, then I traded for a Peavey Special 130( wish I didn't do that !!! Love the Cubs shirt( being originally from Chicago, now living in N Ft Myers Florida). Great video bro!!!
Great job....and at the end......great Jersey......Cubs and Rock on a Marshall amp were made for each other....!!!
I think you got it now. the client will be very pleased.
Dude your knowledge is amazing if I lived close I would totally pay for tech lessons
Honestly man you should make a podcast you are very interesting to listen to
Great video series on this Marshall Super lead repair. You are a true problem solver! (I did not see the Mesa Boogie series you refereed to but in past videos I have heard you talk about it.)
Great vid. I have a 1976 SLP, and they are indeed loud as flark.
I have a Marshall JCM800 4212 50W combo that I have owned from new. In my old metal band, the rhythm guitarist had a 75W Valvestate. However, even flat out, he couldn't drown out my amp with the master volume set to 7. It's amazing how tough these old amps are. I gigged the JCM for fifteen years, and it looked a real mess, but still rocked night after night.
I live in SE England, about an hour down the road from Marshall Amplification. So a couple of years ago, I decided to give "Marsha" a birthday at the place where she was born. I wanted new feet, new Tolex, new fret cloth, a re-cap and re-valve, and replacement of broken pots and missing knobs. I was OK with the price - very reasonable considering the labour - but blanched when they told me the cost of replacing the original Marshall logo. However, when I said I'd have to leave that repair out, the guy leaned forward and snapped the logo in half, saying, "Whoops, my fault. So we'll pay for the logo." Amazing.
The one thing Marshall couldn't replace was the "50W Lead" label, but I found someone on eBay who had laser-etched replacements on real brass instead of brass-coloured plastic. Now, bar some battle scars on the control plate, she looks and sounds good as new. And as loud as ever.
I got my first native sons strap already ordered another one
"Clip and re-strip" hey now ! lol. Thanks for the video, i have never worked on an older Marshall like this so this was a new thing for me to check out. Oldest Marshall ive worked on was a mid 80s JCM 800.
Love the look on your face when you first started playing. Looked like you were trying to keep your head from blowing off of your shoulders. I suppose that says everything there is to say about how loud that 100 Watt Marshall is..... Great video.
Nice pair of videos fixing this classic rock machine! I am impressed by your ability to diagnose the tube socket problem along with a power tube problem. That sucks when new parts have an issue. But a '71 Marshall Super Lead is an amp worth putting some money into to keep in top shape.
Always nice to hear you play.
Wow you had your hands full with fixing that one !
Lol im glad im living vicariously thru yer ears today , sweet amp, go cubs!
Always great for another old Marshall to live another day to make more ears bleed. Good jobb..
Great work. Mentioned to The Missus any Marshall saw at Winterland or The Cow Palace in the '70s was probably one of these.
OK, solid state comment: I have a friend who can not and does not play. Back in the early 70's he was a contractor and agreed to be paid off with a '71 double bound, three color burst, one piece maple neck telecaster and an "Acoustic Instruments 150" head with half stack 4x12 cab. He dragged this stuff up and down the east coast for a couple of decades every time he moved, then put the amp into storage until he decided to lighten his load and gave me the amp. He still has the mint condition Tele in the original HSC. I had to replace two of the speaker coil covers from damage during one of his moves and replace the two prong power cord with a grounded one after my son was almost electrocuted plugging his Tele into it while standing barefoot on the garage floor.
Then, I plugged it in, dimed everything and decided to check it out using my L.P. Jr. and a version of Mississippi Queen and a few other classic riffs until it set off home and car alarms and naturally the police showed up in about ten minutes trying to tell me something about disturbing the peace. But, my ears were ringing so much I could hardly hear what he was saying. I knew he wanted me to stop just from a common sense point of view.
I did a little research on these Acoustic Instruments amps and found they were one of the early first solid state amp that were used by some famous name groups and musicians. Santana were using these amps at Woodstock '69. You can see this in the movie. There is a forum online devoted to these amps. They were fucking loud. I had no room to keep it so I put it up for sale on CL. It sold in two days. People were desperate for anything from these amps. Especially the aluminum handles for the vol, tone etc. These amps were not the same as the GC Acoustic brand of amps. They were advertised as loud and clean. Though they did have a dirty channel. I think the next higher in power were the 360 models. The 150 models were supposed to put out a screaming 150 watts of power. The beauty of these amps was that they were modular. They had circuit boards that could be replaced almost on the fly. I guess Brad could troubleshoot and repair the circuit boards after another was just plugged in and re-use the repaired one. But this company was ahead of its time. For some reason they closed up shop and sold the name to GC, whose amps by that name really sucked.
The face at the end... Priceless!
Sounds fantastic! I have a 1987X Plexi reissue 50 watt, and it's frigging loud too. I can only imagine the decibels on that 100 watt Super Lead. I never play it without a Weber Mass 50 attenuator, to calm the beast down.
The 100 watters aren't really louder, just more top and bottom and a little cleaner.
Enjoyed the vid. I love working or building tube amps. Built a 50 watt 1987 which I'm going to change to bass 1986 spec and then start a JTM45 for which I have NOS GEC KT66 and Mullard 12AX7's.
Yes! JJ's. My EL34 of choice for any Marshalloid. Closest I've found to the Mullard sound in new tubes.
you should try some winged =C= EL34s - they sound awesome to me, especially on high gain. The JJs seem to have a great low end though which is nice for clean.
@@mutarerrs I liked the original "Svetlana winged C" for amps like DSL's that are supposed to have a clean. I haven't cared personally for the Reflektor made Svetlanas, and while I did like the later "=C=" tubes, which were made by the original people that did the first Svetlana tubes, they were either out of production or something else happened, that they started going for stupid prices.
yes - i have a DSL, great call - and i just paid about $85 each for a matched pair of NOS =C=. The JJs are just fine too but the real magic is in my RCA 12AX7 preamp tubes. Haven't tried any mullards yet - def will at some point.
Nice job Brad! Sometimes you gotta dig deep to find multiple issues and get them lined out. I can't even imagine how loud that damn thing is.🤪 My Peavey Bandit 65 with a 10 in. Black Widow speaker is and was more than enough for any gig I ever did! It's now relegated to just occasional home use, and can be turned way down so as not to piss off the neighbors.😆
Sounds very sweet on the quiet mode !
Good job Brad! The clean sound on that amp is really nice. I think you and the customer were right to replace the caps and tubes. The crud in those sockets was not nice! Congratulations on persevering with a difficult diagnostic problem or set of problems!
I will never forget my first KISS concert in the early 70's. I was on the floor along with a thousand or so more, close to the stage. 20 minutes in I had to go for a piss. I get to the can & immediately notice that my ears are ringing, really bad. Left the can & went home.
I had a 71 SL 20some years back. Not having good tech near me, and with my electronics experience I braved changing my caps. Was the start of a fairly decent amp business for a few years... anyways, how you replaced the under board filter cap is exactly how I did it, as well as how most that I know do it.
Nice amps, though, but definitely need attenuation lol
I had a 72' super lead 100w - that thing was so loud! It sounded great at any volume.
Your face at the end, those sound waves crushing your brain...
@30:42 GUM dental scrubbers. *Fantastic* tip. I've been using those for cleaning air passages and metering orifices on weed-eater, lawn mower and old auto carburetors for a few years now. They even have different sizes and bristle stiffness.
Your face of pure pain from how loud the amp is was priceless and just pays a fair tribute to old school Marshall amps! :D lol... great job dude!
JJ Can capacitors are a good replacement choice. I got the same issue with red glowing power tubes, when my Phase Inverter cathodes were weirdly connected to B+ and it took me few hours to find what went wrong. In my case, the bias supply was simply bypassed. My mistake was to put some hot glue to prevent the components to move. It's not the best way to go if you want to mod your amp or fix an issue.
Around 1980 I sold my 1971 Hiwatt100 and bought a 1968 100W 'plexi' Super Lead , holy shit that was the loudest amp I ever heard, too loud for most of the gigs I was doing at the time, people in the audience would duck when I keranged an E! happy days...
Wow now that’s a Sound that supposed to be,your a Good Tech Brad yessssssss