2204 Scratch

Discussion in 'Building the Classics' started by Rockcity, Oct 10, 2018.

  1. Rockcity

    Rockcity Active Member

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    Hi!
    My third amp build, this one in public.
    I decided 2204 build for a simple reason: always wanted one.

    The start - chassis.
    It should be 2204 combo so I got Marshall Master Lead 5010 from early 80s without speaker. Thought V30 would do the job. But first things first

    upload_2018-10-10_9-40-22.jpeg

    upload_2018-10-10_9-41-16.jpeg

    Guts out - guts in

    upload_2018-10-10_9-42-9.jpeg

    .. and the outside

    upload_2018-10-10_9-42-34.jpeg

    upload_2018-10-10_9-47-16.jpeg

    You notice toroidal power transformer. Cheaper and no way of overheating.

    Combo option in a 5010 shell was not so happy solution since 2204 is a wild pony and needs more space. I tried head only into my 2x12 G12M-65 and bingo! Shell is sold, continue with the head cab build. Before that I fell in love in this one found on the net. And I'll try to make exact copy of that.

    upload_2018-10-10_10-0-59.jpeg

    Mine:

    upload_2018-10-10_9-44-32.jpeg

    Yes, now it is upside down and needs new face plate. Original is glued so new one made of plexi is going to be just attached. Bought a piece 1.5 mm thick/thin.

    upload_2018-10-10_10-1-28.jpeg

    Took few measures from the original chassis plate and did a test print before took it to a guy who cuts thing with the laser. No, not Darth

    upload_2018-10-10_10-1-57.jpeg

    Few adjustments had to be done here, but continue with the hard word - the cab.
     

    Attached Files:

    Last edited: Oct 10, 2018
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  2. Rockcity

    Rockcity Active Member

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    I've had many options for the material, but I wanted something light. So plywood or MDF went off and I start my search for the wood. Then I remembered my late grandmother's house full of old stuff. I went there and found a 100 years old pine cupboard. Yes, her house is built more than 100 years ago. Somehow I demolished it and saved few straight boards.

    upload_2018-10-10_10-7-40.jpeg

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    Nails out first. Old rusty nails. Painful job. But not so painful as the next one... damn that old greasy multilayer pain!

    upload_2018-10-10_10-9-51.jpeg

    upload_2018-10-10_10-9-59.jpeg

    I didn't want to damage sharp knives on the next tool - abrichter so I had to take off that pain straight to the wood. After abrichter 100 years pine showed all its beauty. Maybe I should make few guitar tops of it..?

    Cab size is adjusted to the chassis so careful mesurement was on. Cut few boards and by the grace of titebond cab starts to look like... the cab

    upload_2018-10-10_10-14-48.jpeg

    Test with the chassis

    upload_2018-10-10_10-15-11.jpeg

    On the cab's ceiling I will glue thin alu board to prevent the heat from the el34.
    Since I build JCM800 I need to glue those moldings to front and back to make cab looks massive when the tolex is glued on.

    upload_2018-10-10_10-21-19.jpeg

    upload_2018-10-10_10-21-35.jpeg

    In a meantime the rest of the material is on the way from Hungary. I am from Serbia and I can not buy such stuff here. Luckily, in Hungary there is online store with all possible amp/guitar parts.

    upload_2018-10-10_10-23-56.jpeg
     
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  3. Rockcity

    Rockcity Active Member

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    Sand paper on and hard job is about to come. Just because I have not proper tool for my hand milling machine (sorry for non proper term) I have to do that 20 mm radius by the hand. Enjoy and pain at the same time.

    upload_2018-10-10_10-28-9.jpeg

    Rough edges first, then "fine tuning"

    upload_2018-10-10_10-28-35.jpeg

    upload_2018-10-10_10-28-48.jpeg

    upload_2018-10-10_10-28-59.jpeg

    Ready for a filler. Few pieces just went off during hard press of sand paper so filler before tolex.

    upload_2018-10-10_10-29-49.jpeg

    And test print again

    upload_2018-10-10_10-30-59.jpeg

    Next job is plexi cut and face & back plate print. Stay in tune...
     
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  4. Rockcity

    Rockcity Active Member

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    Now I see two photos didn't upload.
    So here they are out of order.
    Me taking out the nails.

    upload_2018-10-10_10-36-26.jpeg

    and few boards after abrichter

    upload_2018-10-10_10-36-42.jpeg
     
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  5. Rockcity

    Rockcity Active Member

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    Sorry for the lousy mobile phone photos, dust does not allow me to bring DLSR in a work place
     
  6. MarshallDog

    MarshallDog Well-Known Member

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    Nice work! What thpe of PT is that one?
     
  7. Rockcity

    Rockcity Active Member

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    I don't know the type but I can post a photo of its generals soon
     
  8. GIBSON67

    GIBSON67 Well-Known Member

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    Good job!
     
  9. Rockcity

    Rockcity Active Member

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    It is PT used in Hi-Fi mostly.
    6.3 V AC tube heating.
    450 V DC all tubes powering.
    Smaller and more efficient than classical "cube" PT.
    Little to none noise.
    Precise output.
    Well isolated so you can touch it during "online" service.
    If you like to see classical "cube" PT just don't open the head cab :)

    upload_2018-10-11_12-51-20.jpeg

    upload_2018-10-11_12-51-35.jpeg
     
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  10. jmp45

    jmp45 Well-Known Member

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    That toroial transformer is interesting in this build. Curious to see if it has an advantage with noise.
     
  11. Rock city

    Rock city New Member

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    I have already tried it and can't tell if there is more or less noise comparing to my other two JMPs, 2203 and 1987x
     
  12. danfrank

    danfrank Well-Known Member

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    Should be quieter for induced hum... IE. Magnetic coupling between iron.
     
  13. ampmadscientist

    ampmadscientist Well-Known Member

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    On the wrong side of the tracks.
    Dude, that is wild. :rock:
    Toroidal transformer requires less turns, is lighter, supposedly more efficient and self-shielding.
    But whether the self-shielding will withstand rock and roll? That is the question which ultimately will be answered.
     
  14. Rock city

    Rock city New Member

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    Test drive with Tokai LS from 1980. thru 2x12 Celestion g12m-65 showed only lack of "more opened tone" comapring to JMP 2203, JCM 2203 and friend's HW 2204. I'll figure the way posting sound only on this thread so you could hear some real deal.
    IMHO, OT is the heart of the amp and this here is domestic made by company named "P& K audio". Comparing to other original and friend's Classic Tone, I think I will try to swap OT with friend's and than be sure.
    Later...
     
  15. Rockcity

    Rockcity Active Member

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    Next: since "printing test" directly to the chassis turned out well, engraver got plexi for laser cutting. A software I am using for engraver's laser and for the next step, printing, is Corel Draw 11. I am the old school and Corel was the very first software I ever used so I+m used to it. Luckily, engraver's laser also uses it.
    About plexi: 1.5 mm turned out too stiff and broke at few points while I was taking it to engraver. So I went back to plexi shop and they gave me 2 mm thick assuring me this wouldn't break. I was only worrying if it will be thin enough to get nicely to the chassis letting all the screws attach to it... it was close but thin enough. Till printing shop, here are the plates:

    upload_2018-10-16_6-28-4.jpeg

    upload_2018-10-16_6-28-11.jpeg

    upload_2018-10-16_6-28-23.jpeg
     

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  16. Rockcity

    Rockcity Active Member

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    Off course a bit: I've got an idea. Since I am building JCM cab not plexi, thought it would be better using this metal face plate. Called at the print shop and they told me they could print directly to the brushed alu plate.
    Took nitro thinner and a cotton rag. Pressed hard and voila!

    upload_2018-10-22_7-47-23.jpeg

    upload_2018-10-22_7-47-34.jpeg

    upload_2018-10-22_7-47-40.jpeg

    upload_2018-10-22_7-47-56.jpeg
     

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  17. Rockcity

    Rockcity Active Member

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    Then I took wide thin metal blade and put between the plate and the chassis. It came off nicely.

    upload_2018-10-22_7-51-40.jpeg
     

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  18. Rockcity

    Rockcity Active Member

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    upload_2018-10-22_7-51-51.jpeg

    Next stop: printing shop
     
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  19. Rockcity

    Rockcity Active Member

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    Face & back plate came last night. Below is just a teaser. Bigger pics after assembling.

    upload_2018-10-24_7-21-16.jpeg

    Scratches on the face plate are battle marks.
     
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  20. jensvonbustenskjol

    jensvonbustenskjol Active Member

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    Nice! Good work!
     

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