JCM900 SL-X 2100 EL34 Version Capacitor Kit Question

Discussion in 'The Workbench' started by jeff.gt, Feb 28, 2020.

  1. jeff.gt

    jeff.gt Member

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    Aloha all, I picked up a capacitor kit from amprepairparts.com, marshall kit MCK-2, contained the JJ filter caps and two axial lead EL-CAP-10/160. Where are the 10/160's used?

    link to the product here:

    http://www.amprepairparts.com/capkits.htm

    Thanks again!

    Jeff
     
  2. Gunner64

    Gunner64 Well-Known Member Premium Member

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    Sorry posted this in your other thread so I'll repeat it here. Those other caps are bias caps..c11 and c16 on the schematic. The schematic states 100v but 160v is ok..you got the schematic?
     
    Last edited: Feb 28, 2020
  3. MickeyJ

    MickeyJ Well-Known Member

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    i think you'll find the positive side of those bias caps goes to ground. the positive end is the one with the groove just beneath the edge.

    you'd want to orientate those bias caps correctly or there will be a pop and some very foul smelling smoke which will cause defects on your babies and you'll red-plate those output tubes.
     
  4. Gunner64

    Gunner64 Well-Known Member Premium Member

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    Mickeys correct, on all that.. however to lessen any confusion Orientate the caps the way they are marked on the pcb. It will say where + goes right by the hole. Just install them the way they came out.

    I did the backwards bias cap hook up thing once when I was young. I had an old Fisher integrated amp that I changed the electrolytics in..they did in fact go pop..loudly ejecting some very nasty smoke and goo..a guy only does that once..:agreed:
     
    Last edited: Feb 28, 2020
  5. jeff.gt

    jeff.gt Member

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    See it all, got the schematic, putting em in!
     
  6. jeff.gt

    jeff.gt Member

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    Bias caps installed, new filter caps in, upped the BR-3 diode to a 6amp...fired it up, no explosions, blown caps etc. Bias was even still at 35ma where I left it before. Problem is now reading 1100v plate voltage at pin 3...tubes aren't red plating. Tried with 2 meters. Mind is blown!
     
  7. jeff.gt

    jeff.gt Member

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    Anddd just looked again the pre-amp tubes arent heating up.
     
  8. jeff.gt

    jeff.gt Member

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    3 of 4 not heating up, going back in to look at BR3
     
  9. jeff.gt

    jeff.gt Member

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    Those burnt traces at BR-3 are shite. One of them the ring around 1 leg of the diode is gone. FML!
     

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