1986 Marshall gut shot

Discussion in 'Amps and Cabs' started by shampoch, Dec 22, 2009.

  1. shampoch

    shampoch Supporting Member

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    I just picked up this awesome 1986 Marshall JCM800 2205 and it sounds friggin' fantastic! Can anyone recognize this (I'm assuming) repair?

    [​IMG]
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  2. WesKuhnley

    WesKuhnley Member

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    What? Are those board mounted pots on a PCB? That amp can't possibly sound good!

    Great amp man! Enjoy it!
     
  3. Senor Forum

    Senor Forum Gold Supporting Member

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    :YinYang:YinYang:rolleyes:
     
  4. John Coloccia

    John Coloccia Cold Supporting Member

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    I had the same repair done on mine. And the IC...twice. Multiple cracked pots. Input jack problems. There's been more over the years...can't remember them all. My circuit board must have a 1/2" thick layer of carbon on it from all the stuff that's blown up over the years. I'm afraid to turn it on. now. Nearly every time I do it ends up costing me money. LOL. Easily the most unreliable amp I've ever owned, including my little battery operated Fender mini twin.

    But when it works, it sounds AWESOME. I think I just got a lemon. In my opinion, though, it's the best sounding amp they made. I just wish mine actually worked! It hasn't blown up in a couple of years, so maybe I finally have all the gremlins worked out.
     
  5. shampoch

    shampoch Supporting Member

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    Thanks - In my 25 years of playing I have plugged into so many JCM800's I have can't count them. Never heard one I loved. I can't believe how good this one sounds. Although it has tons of gain on 10, running the gain on 7 produces awesome Marshall grind and really nice crisp cleans too. It took me 10 seconds of playing to buy it from the shop it was pawned at.
     
  6. Tidewater Custom Shop

    Tidewater Custom Shop Performance Enhancing Guitarworks Supporting Member

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    Sorry, can't help with the mods/repairs you point out.

    Just wanted to comment that I have a '87 2205 and have the same experience as you did with yours. Maybe lucky, but mine is reliable, and kills the Marshall overdriven tone that I love... 10's too much, 7 is the sweet spot.

    As for clean, I actually like this variant of clean. It's not Fender-ish, and thank god for that. I have Fenders to do Fender clean (6L6 & 6V6). The clean channel is big, woody, deep, wide... and projects a lot of wind.

    I've had my 2205 for not yet a year, but I've grown to truly appreciate what it is - and awesome big sounding amp with that coveted Marshall tone.
     
  7. Totally Bored

    Totally Bored Member

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    Hmmm... I'm the original owner of a 86 2205. This amp has been very reliable.


    Here's a gut shot. Hope that helps ?

    [​IMG]
     
  8. Roe

    Roe Member

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    I owned a 1985 2205 for at least 10 years. I much prefer my metro amps and my tw express. I dont need a channel switcher and rarely use much gain
     
  9. John Coloccia

    John Coloccia Cold Supporting Member

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    Like I said, I think I just got a lemon. Other 2205 owners I know have had no problems at all. Seems to just be me :)
     
  10. JerryP

    JerryP Member

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    The wire on the pot is to help with hum. That's stock. Some of those channel switcher 800's had a good amount of hum.
    The diodes have been changed and as Jade said are part of the siwtching power supply. Judging by the looks of the board and the side of that cap I'd say they were hit with high voltage from either a shorted power tube or high voltage damage due to an impedance mismatch or someone using an attenuator.
    Jerry
     
  11. shampoch

    shampoch Supporting Member

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    Sweet - can you email me a "bigger" version of that gut shot pic?
     
  12. Pagan

    Pagan Member

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    Hi to everyone. I'm brand new =). I apologize for my English, I'm from Ukraine. I have a question for you. I want to diploma at the University to make Marshal 2205. Do you have a scheme for P-CAD and Layout. Can You make a quality photos of PCB? I want to draw it=) Thanks for the help =)
     
  13. musikluvr2

    musikluvr2 Senior Member

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    There is no degree for Tube amps. Look at Schematic Heaven, or google search...
     
  14. FrankieSixxxgun

    FrankieSixxxgun Member

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    It's all legit. Looks like those diodes cooked once upon a time and were replaced, and the dual gang pot with the funny ground is the stock gain control. Baby that control, it's almost impossible to find those PCB-mount dual gangs these days. I had a 4211 (100 watt combo version of your amp) and my gain control went out. I ended up getting a solder tab dual gang and running 6 wires to the board. It was a hot mess.
     
  15. big mike

    big mike Moderator - EL34 Emeritas Staff Member

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    My first Marshall was one of those.
    Very cool!
     
  16. Ronsonic

    Ronsonic Member

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    Who ever did it should have cleaned up more. You don't leave burned looking crap like that on a board. Dirt sounds like dirt and provokes future failure. Yeah, yeah it's low voltage stuff and you don't HAVE to, just like I don't have to clean the old pizza boxes and stray socks out of my living room.

    While it's open for pic's, take a Q-Tip and some acetone and see how much of that crap scrubs off from around those diodes. It looks like there's some burned circuit board there that should have been scraped free of carbon by the tech.

    I don't know who's work this is, but it ain't mine.

    Oh, and cool amp! Enjoy.
     

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