JCM800 Kit as a first project

Discussion in 'The Workbench' started by Benighted, Oct 12, 2021.

  1. Benighted

    Benighted Member

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    I was thinking to get a 5F1 kit as most people recommend as a good starting point in building tube amps.

    However, as much as I appreciate the simplicity of 5F1, I would end up with something I'd rarely/never use after the build is complete.

    I would enjoy building and using a JCM800 clone a lot more. However, it bother me it may be an overkill as a first project.

    Thoughts?
     
  2. Dogs of Doom

    Dogs of Doom >>> Moderator <<< Staff Member

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    have you ever built anything? a pedal, or something?

    Probably a good place to start would be build a couple pedals 1st...
     
  3. pedecamp

    pedecamp Well-Known Member

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    Build the 800!!! :yesway:
     
  4. Benighted

    Benighted Member

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    Yes, I have built a couple of pedals and have moderate soldering skills.
     
  5. Dblgun

    Dblgun Well-Known Member

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    Depending on your mechanical aptitude, I don’t think the 800 is an overly difficult build.
     
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  6. thetragichero

    thetragichero Well-Known Member

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    crawl before you walk before you run. pedals under your belt is a good thing, but a MUCH simpler circuit like a champ is better to learn working with high voltages (at 9vdc a pedal just might not pass signal with a short but at hundreds of vdc you could blow fuses or trip breakers or possibly cause damage to yourself or property). not to mention getting a simple single-ended amp (without common mode rejection) hum/noise free will only improve the quality of your bigger amp builds. plus with a decent speaker (my big boy vibrochamp build uses a nice 10", but you could even use a 12") you might be surprised at how fun a champ is
     
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  7. lespaul339

    lespaul339 Well-Known Member

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    It depends on your skill level. If you're good with a soldering iron and can read a schematic or a layout then I say go for it. My first build was my JTM45. I had no issues what so ever, but I did a ton of research and read a couple books on amp building before I dove in. If you have the skills then why not build what you're really wanting? In my opinion it's not technically harder than building a 5F1, there's just a few more parts involved. Build the 800!
     
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  8. PelliX

    PelliX Well-Known Member

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    This. ^ You can't learn to ride a bike from a book. You can't learn to swim in class. You can't... well, lemme stop there and keep this clean. :agreed:
     
  9. Pete Farrington

    Pete Farrington Well-Known Member

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    I think a VibroChamp is a great 1st build - everyone needs a decent practice amp, right?
    Definitely not the tweed champ / deluxe that everyone seems to gravitate towards. They have a horrid cramped chassis, no proper tone controls, and limited scope for tweaks and mods.
    Whereas a VC has a reasonably roomy chassis, a proper tone stack, a cool fx, and plenty of scope to turn the trem into an overdrive preamp. Without the trem, there’s 2 triodes and 2 front panel controls available to repurpose.
    I wish VC kits had been available when I was starting out, they offer an excellent platform for trying out any number of circuit configurations.
     
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  10. XTRXTR

    XTRXTR Well-Known Member

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    You have a couple pedal builds, what about a background in technical building like models, following instructions? If you are confident of your abilities then go for it. Build the amp that will inspire you to complete the work. It's better if you know how the amp works but it is not required. If you run into trouble do not ever do anything but come here and post about it.:hippie: Someone here will help.
     
    Last edited: Oct 17, 2021
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  11. mAx___

    mAx___ Well-Known Member

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    If you don't have them already, get all the help you can from these guys and go for it!


    cradle.jpg knipex.jpeg

    helping hands.jpg
     
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  12. Benighted

    Benighted Member

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    Thanks for the relies, this has been very helpful. I came across this video, which made me appreciate how much time building an amp really takes. Most vendor videos are great, but they make it look a bit too easy.

     
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  13. Chris-in-LA

    Chris-in-LA Well-Known Member

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    I personally started with a few Fender style builds before attempting a 2204. But I had no building experience prior to that. I did have a soldering station and I got my nerve up by watching tube Depot amp building videos. The 2204 is a bit more complex than some of the tweeds but if you think you can follow the step-by-step Valvestorm/Metrospec instructions below, go for it.

    http://valvestorm.com/sites/default/files/50_WATT_KIT_INSTRUCTIONS.pdf
     
  14. Chris-in-LA

    Chris-in-LA Well-Known Member

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    BTW, the Valvestorm 50 watt instructions are for a Plexi. You need to also refer to their 2204 layout for the jcm800 preamp.
     
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  15. Heiko Jakob

    Heiko Jakob Active Member

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    I think it's best to first have a glimps on the schematics before deciding which amp to build and to look which parts are more affordable as spares (especially power- and signal-transformer).
    So it can make sense to go for a older design (fewer parts) and more produced model (cheaper spare parts). Most classic Marshalls are on the fewer parts side, originating from a 1950s Fender Bassman rip off, but the high power 50W or 100W makes spare parts more expensive. More Power = More Copper = More Expensive.
    https://schematichell.com/
     
  16. sloan_amps

    sloan_amps Member

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    I say build the 800. You’ve already built some pedals and have soldering skills, so hopefully that means you can follow any of the tons of resources available for building an 800 style circuit. It’s really a very simple circuit.
     
  17. XTRXTR

    XTRXTR Well-Known Member

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    Just don't solder a bus wire to the back of all the pots!!!!
     
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  18. neikeel

    neikeel Well-Known Member

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    Depending on where you live would depend on which kit.
    I’d go Valvestorm every time and tend to avoid Mojo kits (like their cabs tho’). Admit my personal bias based on trouble shooting on line.
     
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  19. Chris-in-LA

    Chris-in-LA Well-Known Member

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    Having built both Mojo and Valvestorm/Metro 800 kits, I’d agree with @neikeel Mojo does better with Fender style tweed kits, Valvestorm is the way to go for Marshall type stuff. I use Sourmash for the cabs. The Mojotone stuff works fine but their 2204 kit looks nothing like this when complete. They also don’t offer a chassis this small for their 2204 kit.

    upload_2021-10-16_6-21-40.jpeg

    upload_2021-10-16_6-22-7.jpeg
     
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  20. mAx___

    mAx___ Well-Known Member

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    I should write a separate post about my recent experience with Sourmash. He sent me a cab with the wrong specs and didn't want to take it back and fix it. Long story short I had to involve PayPal and ask for a full refund instead. He used every dirty tactic he could to try and weasel out of it. In the end PayPal ruled on my favour and he was forced to pay. He makes nice looking but structurally weak cabs IME.
    Before that, he tried to charge me $40 for a 6" Marshall logo when his cost from CE Distribution is probably less than half that. Even buying it retail the price is $29 all over the internet. I'm done with Sourmash.
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