My first build! JCM800 2204

Discussion in 'Building the Classics' started by adew1, Nov 21, 2020.

  1. adew1

    adew1 Active Member

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    Thanks, coolidge56. I had noticed that too and will sort it out. Thanks for the compliment. I have a long way to go to get to the standard of your builds. :):)
     
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  2. adew1

    adew1 Active Member

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    Chris, you’re right. I gave the amp a good run through this morning and found some great sounds. I find Creambacks quite bright sounding, so just rolling off the treble a bit got me what I wanted. I really want to try this out in a band situation (damned Covid, grrr), as what sounds good in a room may not sit right in a band context.

    A couple of observations about the mods I made:
    1. My fancy switchable bright caps arrangement is quite subtle, as one would expect, and probably not worth the effort. I like the 330pF value best. Of course, once I crank the MV the impact diminishes.
    2. Resonance control. Yes, it adds that Deep switch tone of my JCM2000, but in a band situation will probably be too flubby. Having said that, I’ve not yet tried the amp with a boost in front.
     
  3. adew1

    adew1 Active Member

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    :(
    Yes, I hate soldering to pots :(
    My error was to try to do it like I’ve done many times on guitar pots. Doing it properly, ie separating the shield, twisting it and tinning it, and keeping it away from the signal wire, is much easier and gives less chance of heat damage to the signal wire insulation.
    All part of the learning process! :dude:

    If I have time, I may post a list of other things I learned doing this build, which may be of use to other newbies.
     
  4. Chris-in-LA

    Chris-in-LA Well-Known Member

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    I like the way 2204’s sound with a band. But when I’ve heard mine recorded they probably need the added brightness to cut through better. Either that or just turn them up.
     
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  5. adew1

    adew1 Active Member

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    Metro FX loop added and working as expected. I left it on the -20dB setting, as I use pedals. No need for me to adjust the trim pot, levels match just fine.

    [​IMG]

    Time now to pop it in its cabinet... and move on to the next project!
     
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  6. thetragichero

    thetragichero Well-Known Member

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    one thing to keep in mind while playing an open chassis is that it will be noisier than when you secure it to the bottom shield
    don't feel bad about ordering stuff for more build; i have SO many transformers and organ/pa chassis floating around in various stages that it's insane
    and there's some things you can only learn by building. they'll get cleaner and easier as you go (although still no guarantee that you'll get sound/good sound on first fire up. there's always a gremlin or three to work out. this is where a scope with test signal is invaluable. much better to figure stuff out without assaulting your ears or having to continually strum a guitar)
     
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  7. adew1

    adew1 Active Member

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    Sure, understood. Overall I'm quite happy with the noise level. No hum, pops, squeaks or other untoward noise, just what I would call normal Marshall hiss :) Would be nice to get this level even lower, but I'll leave that for the next build.

    Time to pop it in the cabinet. WARNING: Purists please look away now. Yes, I know, not correct for a JCM800. But I like it. :)

    [​IMG]

    [​IMG]

    [​IMG]
     
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  8. neikeel

    neikeel Well-Known Member

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    [​IMG]

    Don't apologise it looks great - like one of the first MV amps made in '75.
     
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  9. Adieu

    Adieu Well-Known Member

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    Any reason not to use wire better suited to the task?
     
  10. Chris-in-LA

    Chris-in-LA Well-Known Member

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    Looks like one of my 2204 clones.

    8EB2E8F8-2201-4289-A099-52B3E8E8418F.jpeg
     
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  11. Far Rider

    Far Rider Hendrixian VIP Member

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    Beautiful work. Those gold covers are cool!
     
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  12. coolidge56

    coolidge56 Well-Known Member Double Platinum Supporting Member

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    Really nice work! Now straighten your indicator light it's crooked.
     
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  13. adew1

    adew1 Active Member

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    I used RG174, which I think is appropriate. I was just being a gorilla with it, lol. Lesson learned - I now know how to do it properly next time.

    Thanks! Yes, I agree, they are cool - and standard with the Modulus kit. :)

    :applause:Someone, just someone, had to point that out, didn't they? :lol::lol::lol:
    Seriously though, thanks coolidge, appreciate the nice comment. I'm happy with my first effort. It sounds good, looks good, and so far it has not exploded. Three out of three is ok for me! :lol:
     
  14. adew1

    adew1 Active Member

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    Very nice, Chris! Lovely.
     
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  15. coolidge56

    coolidge56 Well-Known Member Double Platinum Supporting Member

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    Sorry my brain doesn't cope well with crooked. You did great on this build, your next amp will be even better. I LOVE that you added some non-traditional features to the amp bravo!
     
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  16. adew1

    adew1 Active Member

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    Don't apologize. It is crooked and it needs sorting out. :D:D
     

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