Silver Jubilee Reissue Input Transformer Swap

Discussion in 'The Workbench' started by Hammerheart, Jan 24, 2020.

  1. Hammerheart

    Hammerheart New Member

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    I'm thinking of getting a 1002 2555x Jubilee from the UK and changing the input transformer so it runs on 120v here in Canada. Providing I get the correct part, how easy a swap is this? When I did my 1w combo this way all the connections were push on spade connections so it was super easy.

    Does anyone have any experience with these heads? Are there any photos of the insides anywhere? I'm hoping it's a solderless job that can be done easily.
     
    Last edited: Jan 24, 2020
  2. Dogs of Doom

    Dogs of Doom Moderator Staff Member

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    you most likely can rewire the existing trans to 120v...

    Usually, changing the trans, will be a drop-in part. You may need to solder. It's not hard, but, if you are not confident in your soldering skills, get someone to do it. It's not a spot where you want failure going on.

    You will need to change the mains fuse as well...
     
  3. Hammerheart

    Hammerheart New Member

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    No, pretty sure Marshall transformers are not multi tapped. I can solder but I'm hoping I won't have to.
     
  4. Dogs of Doom

    Dogs of Doom Moderator Staff Member

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    It's about wiring series vs parallel...
     
  5. Hammerheart

    Hammerheart New Member

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    It the wiring was changeable, they're would likely be a voltage switch on it and there never is with Marshalls.
     
  6. Dogs of Doom

    Dogs of Doom Moderator Staff Member

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  7. Dogs of Doom

    Dogs of Doom Moderator Staff Member

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  8. Hammerheart

    Hammerheart New Member

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    No this is for the 100w version.
     
  9. Dogs of Doom

    Dogs of Doom Moderator Staff Member

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  10. Hammerheart

    Hammerheart New Member

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    I just pulled apart my 20w SC20H to see how that one is connected. I will need to know what I need to replace if I move back to the uk. I thought I'd post the pics so others may have a reference. I'm hoping judging by what I found here that Marshall use push on spades for all their transformer connections. There are zero transformer tapping connections on this amp. It only has a 120v primary as I thought.
    IMG_3139.jpeg IMG_3140.jpeg IMG_3141.jpeg IMG_3142.jpeg IMG_3143.jpeg IMG_3144.jpeg
     
  11. Hammerheart

    Hammerheart New Member

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    That's referring to the fuse rating. Most American voltage amps, even though they run on 120v, the fuse will be rated at 240v. Thats just a list of what fuses you can safely put in it. It's nothing to do with the voltage the amp runs on. Its to save you from doing ohms law to work out the fuse size.
     
  12. Dogs of Doom

    Dogs of Doom Moderator Staff Member

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    watch this at 8:20 onward

     
  13. Hammerheart

    Hammerheart New Member

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    All well and good but the transformers made by Dagnell are two different builds depending on the input voltage required. You dont get the option to change it after its manufactured. My Orange TH30 that I took over from the UK I was able to change the wiring on it so it ran on 120v. This is not the case with Marshalls transformers.

    You can see quite clearly on the photos above that there are only 2 input connections on that SC20H transformer. The rest are connected on the board. there are no cables that do not connect to the board.
    If the transformer was voltage tappable there would be extra cables coming off of it that would likely be joined together in some way allowing you to change the configuration but there are not so you can't.
     
    Last edited: Jan 24, 2020

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