Total Restoration of a 1959 Superlead from 1973

Discussion in 'Building the Classics' started by Matthews Guitars, Oct 9, 2019.

  1. Matthews Guitars

    Matthews Guitars Well-Known Member

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    I'm not sure if this qualifies as building or repair, but for some time now I've been working on a project to completely restore my VERY crusty 1959 Superlead from 1973.

    I'll be adding photos to this topic later but for now, just a quick introduction and rundown.

    I bought a rather sad looking Marshall Superlead a couple months back that still had the original filter capacitors in it. Or more properly, after scraping off an amazing amount of filth and grime and dust, I found old capacitors hiding underneath.

    The cabinet isn't in great shape and, now I know, had been recovered at some point. And then immediately sprayed in white enamel on top of that. I tried everything and nothing would take the paint off that wouldn't also wreck the tolex. So eventually I just stripped the cabinet. In doing so that's when I discovered clear evidence that it had been recovered once already . The gold trim line below the small Marshall logo was the wrong size and type and was just glued in on top of the original trim line, and original tolex was still under that trim line. There are damaged spots all around the edges of the cabinet that were patched with filler. It had some unusual plastic corner protectors on every corner, a type I've never seen before or since. The feet, corners, and handle had all been painted brown and I'll have to say that the spray paint work was well done. But all the gold piping and trim was only gold because it had been hand painted with a brush with gold paint. It probably looked pretty good after being freshly painted and put together...but when I got it, it just looked like a mess.

    I'll redo the cabinet myself, when I have time for it. I just decided that for my purposes I'd have Sourmash build me a new cabinet for it. I'm going to hold back on what I got for a later post. It's nice, I'll say that. Sourmash does GOOD work. Highly recommended!

    Judging by the amount of dust, dirt, and grease that was stuck hard to the chassis, I'd have to say that this amp must have spent the last 20 years in a garage and a very dusty one at that.

    Both the front and rear gold panels have lots of pitting corrosion on them. That takes a pretty abusive environment to do that. And most of the lettering and legends was worn/weathered off. That actually is what started my project and new venture to create and offer brand new replacement metal panels for JMP metal face Marshalls. A project that is about to put my first production examples in my hands in just a few more days.

    At first, I replaced the capacitors and serviced the amp. And I ran it for a while. Got familiar with playing through the beast. Loved it. Will love it again soon.

    It had a master volume mod added to it, but added in place of an input jack. I approve, no holes added.

    The saving grace of this very dirty old amp was that aside from being positively filthy, it was all original with no irreversible mods done to it. The impedance selector jumper socket was disabled, with the individual transformer taps being assigned to specific output jacks, which were labelled, albeit with a permanent marker. Fine, that's not unreasonable and actually very functional. I'll probably opt to stick with that setup and make a special back panel that is marked to match, thus making it look like a rare factory option that never existed.

    To clean the chassis took nothing less than a scraper to get the gunk off it. And under the gunk I found a few rusty spots and ALL the zinc galvanizing had gone dark grey to black. This was just not going to satisfy me.

    So I made the choice to do the full restoration.

    The chassis has been COMPLETELY stripped out, going so far as to drill out the rivets holding the tube sockets in.

    The chassis has been sanded clean and smooth with just a little bit of rust pitting left on it to bear witness to its history, and it has been re-galvanized and yellow zinc chromated, to original factory specifications.

    The transformers were partially disassembled (covers taken off) to reveal that they'd been serving as roach motels for many years. They got a good cleaning and I had the covers blasted clean and they also got re-galvanized and clear zinc chromated to original specs.

    The transformers were sent off to Mercury Magnetics to be tested, baked out to remove moisture from the coil formers, revarnished, and have their leads replaced with new, leaving generous lead length to allow room for a really good lead dress job. They should be back soon.

    All the small metal parts such as tube clamps and the transformer screws and clamps have also been blasted clean and galvanized to original specs.

    Some of the original brass screws were already broken or broke when I went to remove them due to metal fatigue. All new brass hardware has been obtained to replace them.

    This amp, being a late 1973 build, just missed the days of point to point wiring. It has a first generation ST1 board. It was filthy but not as dirty as the top of the chassis. The board was removed, carefully cleaned, and the capacitors that had been replaced in the past that would originally have been mustard caps were replaced with original mustard caps. (Just five on the board, the rest were still there.) The solder traces were carefully cleaned and resoldered with good flux, and cleaned again. Due to corrosion some traces had to be repaired by bridging wires soldered across those traces. The repairs are sound.

    It's getting all new tube sockets of the original type (NOS examples) and mounting system, with snap rings. I have lots of those in stock. The new preamp tube sockets will be upgraded to ceramic types, and will be riveted in as per original factory style.

    If I have a need to replace any components, every effort will be made to source original types, such as Piher resistors.

    Once the transformers arrive and I get the chassis back from the plater's next Tuesday, the reassembly will commence.

    The goal is to bring this amp as close as possible to being as it was in 1973. I've only made one change, a cosmetic choice, but one that was an available option in 1973. I'll leave that as a surprise when I post photos.
     
  2. South Park

    South Park Well-Known Member

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    It sounds like great job you are doing . Go for it
     
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  3. Amadeus91

    Amadeus91 Active Member

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    Like a Phoenix she will rise again and roar.
    Look forward to your progress and success in breathing new life into her.
     
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  4. Matthews Guitars

    Matthews Guitars Well-Known Member

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    IMG_2180.JPG IMG_2181.JPG




    IMG_2182.JPG IMG_2183.JPG IMG_2479.JPG IMG_2478.JPG IMG_2477.JPG




    The first four photos show you what I had to start with. I doubt you've seen many Marshalls that had more dirt on them short of salvaging them after a natural disaster like digging them out of a mud slide or a burned nightclub.

    The last three show the SAME chassis, transformer covers, and small parts now.

    Actually the chassis was sent back to the plater's because they didn't apply the requested yellow chromate coating, and so I'll have that back in a few days.
     
  5. Matthews Guitars

    Matthews Guitars Well-Known Member

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    IMG_2447_s.jpg


    And this is what it will be going into when it's done!
     
  6. Matthews Guitars

    Matthews Guitars Well-Known Member

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    Here's the chassis, fresh back from regalvanizing with a fresh coat of yellow zinc chromate.

    Note that there are still some small pits visible in the upper surface. I elected to leave those in there as evidence that this is an original restored chassis, and not a reproduction or replica.



    Replated 73 superlead chassis 1.jpg Replated 73 Superlead chassis 2.jpg
     
  7. herbvis

    herbvis Active Member

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    Was that pricey?
     
  8. Matthews Guitars

    Matthews Guitars Well-Known Member

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    I had the chassis redone along with the transformer end bells and most of the small metal parts for 200 dollars. I think that's fair. The parts that were clear chromated had to go in a separate batch. And there is a batch charge for each process requested. So one for yellow chromate, one for clear chromate.

    When all the parts arrive (the transformers are at Mercury Magnetics getting tested, baked out, and revarnished, plus new leads) then I begin reassembly. It's going to be fun and will actually qualify as my first full amp build in more than 20 years.
     
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  9. Guitar-Rocker

    Guitar-Rocker Well-Known Member

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    Nice touch on the replating, I'm sure it will make reassembly more fun now, and it will definitely look as good as possible
     
  10. South Park

    South Park Well-Known Member

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    Nice job
     
  11. neikeel

    neikeel Well-Known Member

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    I must confess that when you started the project I wondered why all the effort. Personally I really like amps that are lightly worn and have a patina to them, I can build new amps all the time.
    However looking at what you started with and where you are going I think it will be a great restoration. I am very familiar with this type of work as for many years I used to restore old motorcycles.
    I hope you are practising your wire lacing technique to get all the runs correct.
     
  12. Matthews Guitars

    Matthews Guitars Well-Known Member

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    My 2203 is "lightly worn with patina" and I'm cool with it like that. I actually want it to stay just as it is. But the 1959 was the victim of neglect if not outright abuse. And since I have definite plans for it, as a showcase for my restoration metal panels, I want it looking as sharp and fully restored as possible. So I decided that restoration would be appropriate.

    The original cabinet had been recovered at some point in the past...and immediately spray painted white with enamel. Nothing on earth would get that enamel off without ruining the tolex underneath. When I stripped it I found plenty of evidence that it was previously recovered. Such as the original gold string still in its groove and still sitting on top of tolex. The previous guy to mess with it had just cut the tolex off and glued a new string down over the old one. What a hack job.

    I'm not going to say that I won't be offering "frame off" restoration level services, too.

    Between myself and some people I know, we have the capability to restore a heavily hacked, modded, and drilled out Marshall chassis to its original specifications and glory. If someone has a modded '68 Plexi and wishes that its OT transformer window hadn't been hacked out by some maniac with a hole saw or a plasma cutter to fit a Magnavox TV transformer in it, I'm the man to talk to about restoring it to as it was. The damaged area can be cut out and a new section laid in, cut to original transformer cutout specifications, welded, ground flush, finshed to original appearance, and then regalvanize it. It'd look like it never happened. Any hole from small drill holes to transformer cutouts can be made to disappear.

    In fact I'm looking for a hacked chassis or two to practice on. Just in case you know someone who has a butchered Marshall that needs to be brought back from the dead.


    As for wire dress, I'm a disciple of Dave Reeves (Of Hiwatt fame) and I have a mentor who is a maniac for wire dress. It'll be a fine job.
     
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  13. Goldfinger

    Goldfinger Active Member

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    I had two '73 hand-wired JMP Super Lead 100 heads that I purchased for $500.00 each. Selling them was the worst gear sold decision I've ever made.
     
    Last edited: Oct 26, 2019
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  14. Matthews Guitars

    Matthews Guitars Well-Known Member

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    It hurts just to read that. But then again, I've heard stories of pawn shops refusing to give more than a hundred bucks for a JMP Marshall, back in the mid 80s. Around the time I bought my first real amp, a Fender Pro Reverb (also a '73 model) for 75 bucks.
     
  15. Matthews Guitars

    Matthews Guitars Well-Known Member

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    Well, it's apparently going to be several weeks before I get my transformers back from Mercury Magnetics. No problem, there's plenty to attend to in the meantime. I guess I can start on stripping a 1960 cabinet and preparing it for its rebirth in purple levant with gold trim and Bluesbreaker grille cloth.
     
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  16. Matthews Guitars

    Matthews Guitars Well-Known Member

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    Here's the head cabinet along with the freshly redone 1960A cabinet I completed yesterday. Working on the bottom cabinet now.

    [​IMG]
     

    Attached Files:

  17. MarshallDog

    MarshallDog Well-Known Member Premium Member

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    Dam man, this is very interesting and you do some very spot on detailed work...Marshalldog likes that. Where did you and how did you find a place to treat the end bells and the chassis??? The cabs look great!!!!
     
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  18. Matthews Guitars

    Matthews Guitars Well-Known Member

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    There's a plating shop in Pompano Beach, FL, that does hot dip zinc galvanizing and also clear and yellow chromating. (Done after the galvanize dip is done.) They did my work for me. But it's far from the ONLY plating shop around that can do this. Just google for "Galvanizing service" and you'll find lots of hits. There's probably one in your general area.

    Where there is manufacturing of steel products, there is a galvanizer nearby.
     
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  19. Amadeus91

    Amadeus91 Active Member

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    ^^^^Just typed bad ass into google and your name came up as a first hit.^^^^^
    Outstanding work.
     
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  20. Matthews Guitars

    Matthews Guitars Well-Known Member

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    I cut two back boards for the cabinets last night, out of 13mm Baltic Birch. I don't like particle board and those original backs are deteriorating anyway. No sense in keeping them.

    The bottom cabinet had a high water mark on it, about three inches up. Speakers are fine. I suspect that water related issue may have led to the glue joint failures. It could at least be a contributing factor, and it's one that sure isn't good for particle board.
     
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