Just Got A Dsl100 For Cheap, But I Found This Inside!

Discussion in 'Marshall Amps' started by starsend, Dec 5, 2018.

  1. starsend

    starsend New Member

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    Hello everyone, first of all let me introduce myself, my name is Andre and I while this is my first post, I have enjoyed reading this forum for a long time, but now it is good to be a member!

    I just got a JCM2000 DSL100 from 1998 from a pawn shop for 350 euros, but when I opened it I found this inside. It is apparently some kind of mod, but I have no idea which. There's this bunch of components here all covered in hot glue, and then an extra pot sticking out from behind V8.

    Also, the bias thingy is lose and doesn't give me any reading at all. I suspect maybe the pot is now controlling the bias? But then where do I take the measurement?

    I have read about the bias drift problem, so might this be a (sloppy) fix? Maybe with the original bias board bypassed?

    Sorry for the bad pictures, I took them to send them to the guy who sold it to me. As soon as I get back to the studio I will take some better ones if you guys need them.

    Thank you very much for reading and any help would be greatly appreciated. A

    Andre
    Screen Shot 2018-12-05 at 3.24.58 PM.jpg Screen Shot 2018-12-05 at 3.25.19 PM.jpg IMG_0086.jpg IMG_0088.jpg IMG_0087.jpg
     
  2. johan.b

    johan.b Well-Known Member

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    Last edited: Dec 5, 2018
  3. ricksconnected

    ricksconnected Well-Known Member

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  4. starsend

    starsend New Member

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    That is exactly what I was thinking of doing. The only problem is that there's a cap
    hanging from the top pcb as well (where the back panel outputs are). As long as they didn't score the PCB or anything like that, I guess it would be a great option. I am going to ask for some money back from the seller though, then proceed with this option!

    Thanks!

     
  5. Gunner64

    Gunner64 Well-Known Member

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    The bias drift fix isolates pin 5 on the output tubes, effectively bypassing the trace to pin 5. If that mess is a bias drift fix the trace is probably cut, which is no big deal as the dr. Tube bias kit drills out the pcb around pin 5 anyway, taking the trace out of the bias circuit, and moving it away from the b+.
     
  6. starsend

    starsend New Member

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    I'm pretty sure that's what it is. Truth be told, if they agree to refund me part of the amp I will just get both the main board and the Bias board from proaudioservice and put them in and forget about it. I'm waiting to see what the seller says. I do think he acted in good faith since it's a kind of pawn shop and I doubt they knew what they had.

    The smell of hot glue when I power it on is killing me!

     
  7. Herbert Mitchell Pearrow

    Herbert Mitchell Pearrow Well-Known Member

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    Welcome to the forum brother,you as mentioned already, know you are in good hands here
     
  8. starsend

    starsend New Member

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    Thank you very much! I certainly do!
     
  9. ampmadscientist

    ampmadscientist Well-Known Member

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    On the wrong side of the tracks.
    That amp is totally trashed.
    Send it back and get a refund. You wasted 350 Euros.
    That guy ripped you off.

    That fact is: this amp is worth 75-100 at the most.

    And welcome to the forum.
    Sorry you got fleeced by a con artist...
     
    Last edited: Dec 5, 2018
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  10. charveldan

    charveldan Well-Known Member

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    [​IMG]

    Run Forrest run ...
     
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  11. Gunner64

    Gunner64 Well-Known Member

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    The thing about the replacement boards that bothers me is there are reports of the new boards developing the same condition the old ones had. They supposedly changed the material the boards were made from, but from what I see the bias and the b+ traces being in such close proximity hasn't been addressed.I have a 2000 jcm2000 dsl 100 that doesn't have the drift issue now, but I bought the dr. Tube stable bias kit just in case. With This kit you will not have the issue again ever, with a new factory board it seems to me a kind of crapshoot just like the originals..it may or may not develop the issue again. The Dr. Tube bias mod was $80, a new board over $200. Ones a rock solid true fix, the other I have as much faith in as I do my stock board from 2000..in my case I think it's just a matter of time...but in my case I have under $60 in the amp..in your case I agree you should get a partial refund for that mess..
     
  12. starsend

    starsend New Member

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    The guy is fine with me returning it, which after reading your comments seems to be the best option...
     
  13. ampmadscientist

    ampmadscientist Well-Known Member

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    Return it right now. Get your money back immediately.
    You could have bought a working good DSL for 350-400 Euros.

    Do not even mess around trying to repair that abortion. Run Away.
    Run Forest, run.
     
    Last edited: Dec 5, 2018
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  14. ampmadscientist

    ampmadscientist Well-Known Member

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    I think the Dr. Tube may be better than a new board.
     
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  15. ampmadscientist

    ampmadscientist Well-Known Member

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    It's the spacing of the circuit tracks.
    The material slowly absorbs water (humidity) over long periods, and the insulation is breaking down.
    But in places where the humidity is very low, it lasts a lot longer. If you live in the desert, no problems.

    classic.png

    Classic.
     
    Last edited: Dec 5, 2018
  16. starsend

    starsend New Member

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    The amp is in a box waiting to be collected. Back it goes... My other Marshalls will be happy one of the competition has been sent away...

    Thank you all for the replies!
     
  17. jlinde1973

    jlinde1973 Well-Known Member

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    Buying a used amp is like a box of chocolates...you never know what you're gonna get!
     
  18. jlinde1973

    jlinde1973 Well-Known Member

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    I found a bag of weed tucked behind a reverb tank on an amp I bought online once. I gave him positive feedback of course!
     
  19. starsend

    starsend New Member

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    Haha
     
  20. ampmadscientist

    ampmadscientist Well-Known Member

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    I found a bag of weed tucked behind a reverb tank..."

    Was it any good?
     
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