spacer sleeve and screws JTM50, 1968

Discussion in 'Building the Classics' started by kaperski, Nov 7, 2021.

  1. kaperski

    kaperski New Member

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    Hello everybody,

    my name is Jürgen 44 from Germany and so far only a ghost reader;)! I am planing to bild a JTM50 and want to do it as close as possible to the orginal. My question today is about the fixing from the turretboard to the metal chassis.
    I think, I have seen in old pictures some aluminium spacer sleeves and brass original screws (AF, UNC, UNF, BSF, BSW, BA, NPT....?) - but which sizes?

    Thank you for an answer, Jürgen
     
  2. South Park

    South Park Well-Known Member

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    Greetings Jurgen you can use just about anything for standoffs . I try to salvage parts like this when I can . Just use locking nuts on as much as possible things can work lose
     
  3. Chris-in-LA

    Chris-in-LA Well-Known Member

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  4. Marcomel79

    Marcomel79 Well-Known Member

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    Hey Jürgen. Tube town from Germany has them
     
  5. Matthews Guitars

    Matthews Guitars Well-Known Member

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    The screws are BA series thread, but I can't remember if it's BA 6 or BA 4. Whichever is closer to 4-40 UNC is right.

    All 60s and most 70s Marshalls were built with BA hardware.
     
  6. AndyD

    AndyD Well-Known Member

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    6BA for the stand offs.
     
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  7. kaperski

    kaperski New Member

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    Thanks a lot for the valvestorm link:yesway: and the warm welcome. This is exactly what I need. But can somebody explane to me the first 3 variations. For e.g. the smaler and larger bolts? Which do I need - 1, 2 or 3?
    I got a laydown transformer from heyboer and a IEC Socket and my plan is to buy the Ceriatone chassis with frontplate.
     
  8. neikeel

    neikeel Well-Known Member

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    Originals are aluminium tubing with 6BA screws
    Spacers are 3/4" long
    Screws are 1 1/4" long
    You need two nuts and two serrated lock washers per screw. That way the screw and spacer are bolted securely to the chassis and then you fit the board over and secure that with another washer and 6BA nut.

    The Valvestorm ones are US sizes (the nuts are flatter and wider across the flats) vs the correct original ones (if we are being picky). The transformer screws and nuts are 2BA and the output valve, filter cap, selectors are all 4BA.
    I cannot see anything remotely like the original stuff in Tubetown (got an exact link)?

    The Ceriatone chassis are nice but the holes will probably be drilled for their circuit board. Are you going for Paxolin and turrets? If so I have some spare original type that was given to me that you can have one for postage costs (you will need to fit your own turrets).

    These look fantastic:https://www.marshallforum.com/threads/50w-plexi-chassis-replica.123569/
     
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  9. Matthews Guitars

    Matthews Guitars Well-Known Member

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    I was able to obtain all BA hardware I needed for two Superlead restorations simply by shopping for BA brass hardware on the UK eBay site. Yes, I'm that detail oriented. Sure, I could get screws that would fit and work from my local hardware store, but for the minor additional cost of getting correct hardware, I was totally willing to spring for it.
     
  10. kaperski

    kaperski New Member

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    There seem to be no more screws with brass 4BA and 1 ¼ "length. They are sold out at gwr-fasteners. Tubetown does not sell BA copper screws, only aluminum spacers. The Ceriatone sheet metal AMP chassis is imprecise in the corners and has additional holes for the bias and maybe wrong turret holes. The front panel is really, really nice. The modulusamplification chassis has better finished corners, but too many side holes and the front panel is imprecise. There is no one who sells a correct sheet metal chassis without or right holes. It's just a compromise between orderability and aesthetics.

    I think, i need a phenolic board like this

    https://modulusamplification.com/Black-Flag-1987-Turret-Board-Assy-brown-phenolic-P5932332.aspx
     
  11. StuC

    StuC Active Member

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    I have chassis and turret boards if you're interested. I used my JTM50 for reference and they would have been direct copies (other than the IEC cutout and deleting a couple of redundant holes), but the fabricators decided to deviate from my drawing and seam weld the corners. The dimensions and hole sizes are correct anyway.

    [​IMG]

    [​IMG]
     
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  12. kaperski

    kaperski New Member

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    Thanks neikeel for your offer, but I need a chassis with a front panel (JTM logo), which I cannot reproduce in Germany.
     
  13. neikeel

    neikeel Well-Known Member

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  14. AndyD

    AndyD Well-Known Member

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    [​IMG]
    @StuC put me onto these guys. Came in the post today! Could only get 1 inch 6BA instead of 1 1/4 inch mentioned by @neikeel . Also the spacers from Farnell are 1/2 long instead of 3/4 inch. Near enough for me.:)
     
    Last edited: Nov 10, 2021
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  15. Chris-in-LA

    Chris-in-LA Well-Known Member

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    Score!
     
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  16. AndyD

    AndyD Well-Known Member

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    Hi Neil, curious to know if the hole spacing for their panels would fit a genuine Marshall chassis?
     
  17. neikeel

    neikeel Well-Known Member

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    I think that they do with minor tweaking. I have a spare that you can offer up.
    Afraid Chris has my original 67 JTM45 and 68 JMP50 front panels at the moment for his colour matching.
     
  18. AndyD

    AndyD Well-Known Member

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    Thanks Neil, thats useful to know. I will probably just go ahead and buy one in the meantime.
    Appreciate the offer.
     

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