Thinking About Building This Amp.

Discussion in 'Building the Classics' started by MarshallDog, Oct 12, 2017.

  1. MarshallDog

    MarshallDog Well-Known Member

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    As winter approaches, I am thinking of building this amp. I have researched it a lot and it seems like one awesome amp, just what I'm looking for and it seems to be a high quality kit. I dont have the knowledge to build my own amp from scratch but I have more than enough skills to build this amp and do it like a pro.

    What do you guys think? See any issues, concerns, has anyone else here built this one?

    https://www.tubedepot.com/products/classic-british-jtm45-plus-tube-guitar-amp-kit-combo

    I called them and asked about a deduct for no speaker and tubes. I will use a Celestion G12M-65 Creamback and I have more than enough tubes to fill this amp up. They said no problem and the price would drop to 875.00.

    Any advice?
     
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  2. stickyfinger

    stickyfinger Active Member

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    Id just go all out and use Robs parts from Valvestom. Resale on a tube depot kit probably not good.
     
  3. ibmorjamn

    ibmorjamn Well-Known Member

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    I would source it myself and build it. Get the tx from classic tone . They make original copy's . plenty of schematics around and Mouser has everything. However , when it comes to the cab and faceplate you might be good.
     
  4. liontato

    liontato Well-Known Member

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    Take your time with it. Be meticulous. You’ll be fine. Great amp to start with. Follow everything to the dot.
     
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  5. MarshallDog

    MarshallDog Well-Known Member

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    I hear you but I would probably never sell it.
     
  6. stickyfinger

    stickyfinger Active Member

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    They might be "copys" like everyone else that use paper bobbin (if that really means much) these days.
    They don't copy the core metals composition like Merren.

    Id seriously just drop the extra 400-500$ and go big. That way you wont get the bug and say what if I used sozos or Mustards lol
     
  7. ibmorjamn

    ibmorjamn Well-Known Member

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    I would not , but you can buy decent non cork sniffer stuff. Jmho
     
  8. neikeel

    neikeel Well-Known Member

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    Exactly what I would do.
    High quality parts at good prices. I would use Merren/Marstran/Metro/Calssic tone iron in that order of priority.
    You can build any amp, if it works you will be happy, for a while and then you will compare it with better stuff and realise you came up short when you put your hands in your pocket to buy quality parts.
    A high gain fizz box is less critical on parts quality
     
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  9. liontato

    liontato Well-Known Member

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    MD, the guys recommending Valvestorm parts and good iron are correct. It does make a huge difference in tone. I’m simply saying to not hold back if you want to build. It’s very rewarding and fun. This amp isn’t terribly complicated and would be a good start as long as you follow the layout precisely and never get in a hurry. The transformers greatly affect tone. Caps and then resistors in that order. Get some good parts and you’ll be glad you did.
     
  10. pedecamp

    pedecamp Well-Known Member

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    I like those videos that's a nice sounding amp, pretty heavy tone I wasn't expecting. JTM45 Plus, I guess the Plus is their own twist on the JTM45 to make it sound good.
     
  11. Garrett

    Garrett Active Member

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    I built the head version from Tube Depot.

    They should not call it a JTM45. It's not even close when you compare TD's circuit to the actual JTM45. It uses EL34's and not JT66's, split cathode as well as circuit tweaks.

    It's not a bad sounding amp and the cleans are on the glassy side.

    I'm one that doesn't care for a MV on this amp. Installed a PPIMV from Triode. Amp is fizzy and choked until you have the MV at 3/4.

    Sounds good when you push the volume and has that Marshall tone.

    If you are looking for a true JTM, the Tube Depot kit is not it.
     
  12. MarshallDog

    MarshallDog Well-Known Member

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    Thanks for the great info. So you are saying if you add TDS MV mod kit, it is fizzy and choked until the MV is at 3/4 and that’s why you went with the PPIMV option?

    Did the build go well without issues?
     
  13. harleytech

    harleytech Active Member

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    Go with Valvestorm.. Metro Amps...
    No tech Support With Tube Depot if you have a question about something...
    You're on your own... With Metro amps you have the Metro Forum...
    A lot of info on there... I know , I built 3 Metro Amps from Valvestorm
    Quality Hardware, chassis and Head Boxes.. Built the way Marshall did..
    JMHO...
     
    Last edited: Oct 20, 2017 at 7:32 AM
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  14. ampmadscientist

    ampmadscientist Well-Known Member

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    I would recommend a steel chassis, and solder ground lugs to the chassis before installing any of the parts.
    As you build it, the circuit grounds solder to your ground lugs.

    On an aluminum chassis, the ground lugs need to be mig/tig really. Any method that depends on screws alone is not the way to safely ground aluminum.
    Then, you can solder to your lugs...
    Two different types of metal contacting each-other will produce a layer of oxide, causing ground connections to fail.
    The oxide layer is a perfect insulator. It stops all conductivity.
    The ground connections need to be attached by a method which prevents oxidization. (you can't solder to aluminum)

    This is why there are special rules/requirements for safe grounding of aluminum chassis.
    a. no dissimilar metals.
    b. Aluminum chassis cannot be used as a current path.
    c. a connection cannot oxidize.

    The point being: on both steel and aluminum, grounding of high voltage circuits by screws alone, is not a great idea.

    The grounds "should be" permanently attached. On steel, this can be accomplished by soldering...
    Plan out your grounds locations. Don't forget the mains earth green wire needs a lug too.

    1. drill your ground lug hole (use an existing hole), and attach the lug w/ a small screw, to hold it steady.
    2. Preheat the chassis w a heat gun.
    3. Solder (tig) all lugs to chassis permanently with a High Power soldering iron (tig welder).
    4. Clean up the flux, and crud...etc...after soldering (tigging) the lugs.
    5. Install the final hardware into the holes..I like nylock SS nuts.

    (i like to use stainless steel ground lugs...) which I can buy at the hardware store.
    Then I solder those pups in.

    Then, start building yer amp. Solder your circuit grounds to yer ground lugs.
     
    Last edited: Oct 20, 2017 at 9:25 AM
  15. MarshallDog

    MarshallDog Well-Known Member

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    Wow, sounds like I should look into it. Do they offer a 1X12 combo in a Plexi or JTM chassis? How are their instructions, etc? I will try to look at their websites. I assume the amps sound killer??
     
  16. neikeel

    neikeel Well-Known Member

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    They do head cabs and chassis, but not normally combos.
    http://valvestorm.com/Products
    What are you after? From your list you seem to have the 2204 and Friedman covered so I would go JTM45 with a 1x12 and Celestion Gold and aim for as close to Marshall o/e as possible. He sells Bianchi and normal Mustards. Don't use carbon comps or metal films, I use Piher carbon films but it is probably cork sniffing so the stock CF work well.
    Build instruction link here: JTM_45_KIT_V2.1.pdf
    Plenty of help on Metro forum.
    I don't personally weld chassis and have no issue with the aluminium chassis but think the steel chassis is a good option if you go for a combo.
     
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  17. harleytech

    harleytech Active Member

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    I used the aluminum chassis on my JTM 45 with excellent results...
    No problems what so ever... Instructions are top notch...
     
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  18. DeathAdder

    DeathAdder Member

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    Excatamundo. He should check out http://www.triodeelectronics.com/ as well.
     
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  19. ampmadscientist

    ampmadscientist Well-Known Member

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    In your bathtub.
    No problems..until there is a problem.

    Electrical codes created to stop people from being electrocuted.

    It's the law.
    And if you knew anything about electrical safety codes (which you clearly do not...) you would take the safety more seriously.

    It's not up to you......you don't make our safety rules....and neither does triode electronics.

    "Instructions are top notch..."

    Yeah, "top notch," except for safety compliance.

    NEC certified...Certified Electrician....test safety compliance professionally for Medical, Aerospace, Miltary, and consumer appliances.
    AND I said so. Quote me.
     
    Last edited: Oct 21, 2017 at 9:48 AM
  20. Guitar-Rocker

    Guitar-Rocker Well-Known Member

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    I challenged Mad Amp several months ago to show the article from the NEC about grounding of aluminum enclosures for amps, which he never has. The reason why? It doesn't exist. It's only Mad Amps opinion versus others opinions.

    I also challenged Mad Amp to show proof that anyone died from use of an aluminum amp chassis, or was ever severely hurt from the use of the same.

    He never provided that either.

    While people may have some valid points in their arguments, it doesn't make it law. The word aluminum is most egregious to Mad Amp any time he hears it. I really get tired of this garbage.
     
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