Marshall Museum Bletchley "No One Amp" Replica Build on Old Chassis

Discussion in 'Building the Classics' started by pleximaster, Jan 12, 2020.

  1. pleximaster

    pleximaster Well-Known Member

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    I was building a replica of the so called "No One Amp" that Jim Marshall called it. Its been debated whether or not this was the actual chassis that was the first one and the one demoed at that Ealing Club sometime in September 1963 (not 62). Lest leave it at that.

    However, the reson for this replica build came from the urge to find out what that chassis sounded like, with those rare Elstone transformers. In the build process of the previous thread I was approached by a member here to restore an old chassis that had been parted out as the previous owner thought it was a home-brew amp. I got curious and and excepted to restore it. It came last week and I had all the other parts ready for my own build on a blank chassis. My own chassis hadn't been cut for valves and pots so I could not help myself putting a functional chassis together. Will get other parts for my own build...

    Here was the stripped chassis... 1.jpg 2.jpg 3.jpg 4.jpg 5.jpg 6.jpg 7.jpg 8.jpg 9.jpg

    And this is how it turned out. I copied it from at the Chassis at the museum down to the obvious changed parts like the sprague on the presence knob, the later 60´s diode. It has vintage Mullards ecc83´s a Mullard GZ34 and Brimar 6L6/5881 valves. Almost all the same manufacturer, tolerance and specs. The brown rectangular RS 0.1uF coupling is 600 cold instead of 400volt. The grey filter cap is slighty thinner but longer than on the original No One. Wirings to the input jack differs as I left them as they were from the stripped chassis. The original inside filtercap in the old stripped chassis is replaced as it did not reform.

    Same McMurdo 9-pins valve sockets for the preamp valves as the No One. Cinch bakelite valve sockets for octals. RS 7x27 hole board. Original potentiometers and correct valve with the Bass and Mid control in switched places as an old Fender Bassman.

    In fact all parts on the No One amp is 100% clone of the 1959 Bassman but with British equivalent parts.

    I added a 250uf on the first 820 ohm on the board, this one is missing on the No One chassis (But must have been there) I also mounted the 150k dropping resistor for the board instead of a flying one as on No One amp (Safety reasons)

    The sound astonished me as it had tones of gain and quite bright. The OT saturates very fast.



    Thanks the best plexi

    The chassis with snowwhite background is the original No One Amp... the pics on the right is the replica build on that old stripped chassis... :)

    NO ONe Replica Old Chassis.jpg
     
    Last edited: Jan 18, 2020
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  2. pleximaster

    pleximaster Well-Known Member

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  3. stickyfinger

    stickyfinger Well-Known Member

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    Which one is the real one again? The right or was it the left?
     
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  4. pedecamp

    pedecamp Well-Known Member

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    Sounds good :yesway:
     
  5. Dblgun

    Dblgun Member

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    Great piece of history and your work is top notch. Thanks for sharing.
     
  6. ricksdisconnected

    ricksdisconnected Well-Known Member

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    we can do that?
     
    Last edited: Jan 13, 2020
  7. South Park

    South Park Well-Known Member

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    Great job . It being proto type amp it is hard to say what changes may have Ben made that long ago. Only the builder knows what went into it . No matter how close you get it is a pease of history
     
  8. tomsvintage

    tomsvintage Well-Known Member

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    Another job well done to say the least !!!! Excellent reproduction and amazing sound :) A clear acrylic cab could house that one !!
     
    Last edited: Jan 13, 2020
  9. pleximaster

    pleximaster Well-Known Member

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    An acrylic cab is the plan for these! :)

    plexi
     
  10. pleximaster

    pleximaster Well-Known Member

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    However, this whole project should not be taken as a serious scientific experiment! :) The only serious thing about it is too hav e some serious fun while doing it! ;)

    Keep Calm and Carrey on Amping! :=)

    plexi
     
    Last edited: Jan 18, 2020
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  11. Chris-in-LA

    Chris-in-LA Well-Known Member

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    Those two chassis are so similar, very eerie.
     
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  12. shakti

    shakti Active Member

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    Superb job, even the slightly crooked capacitor alignment copied!
     
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  13. pleximaster

    pleximaster Well-Known Member

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    I got the parts from you today! Thanks a lot! Your parts will go into the build that is for me!

    did the parts I send to you arrived yet?

    best plexi
     
  14. Seanxk

    Seanxk Well-Known Member

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    Superb work, really great to see things back and moving along nicely.
     
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  15. pleximaster

    pleximaster Well-Known Member

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    Just from memory this is what parts you need for building a replica of No One Amp!
    plexi

    Replica build parts list


    1 x chassis
    4x corner mounts
    1 x Bulgin jack mains
    1 x Bulgin fuse
    3 x Bulgin switches
    6 x RS/AB pots (3 x 1Meg, 1 x 20k, 1 x 250k, 1 x 5k)
    5 x old Rendar input jacks Black nuts, metal washers
    2 x 1k 1 watt amp resistor
    1 x 4,7k 1 watt amp resistor
    2x27 hole paxolin board
    50 x vintage turrets
    3 x McMurdo 9-pin valve sockets
    3 x Cinch octal valve sockets
    1 x 550-556 pf silver mica
    1 x 250 pf silver mica
    1 x 47uf silver mica
    1 x 250 uf grey RS electrolyte
    1 x 100 pf red dog bone RS cap
    1 x 8 uf 450 v RS electrolyte
    5 x 0.02 uf RS grey Paper in oil caps
    2 x 0.1 uf RS grey Paper in oil caps
    1 x 0.1 uf RS brown box cap
    1 x 0.1 sprague black beauty cap
    2 x vintage cap holders
    1 x 16 uf 450–500v
    1 x 32-32 uf 450-500v

    Valves
    3 x ecc83
    2 x kt66
    1 x gz34

    1 x set Elstone transformers (OT MT choke)
    1 x red pilot lamp
    1 x RS grey snubber cap
    1 x RS grey polarity cap
    4 x screws for board mount 6BA
    4 x aluminium distance for board mount
    6 x screws 6BA for 9-pin socket mounts
    6 x rubber grommet sets for for 9-pin socket mounts
    5 x rubber grommets 9 mm for wires
    10 x lug ear mounts
    20 x anti shock washer for 6BA
    16 x anti shock washers for 4BA
    16 x 6BA counter sunk screws for mounting corner mounts
    18 x 4BA nuts
    34 x 6BA nuts

    1/2 vintage carbon comp resistors
    4 x 68k
    5 x 100k
    2 x 820 ohm
    2 x 270k
    2 x 56k
    4 x 1 meg
    1 x 470 ohm
    1 x 10k
    1 x 82k
    2 x 220k
    1 x 150k
    1 x 15k
    1 x 27k

    1 x 10k 2 watt
    1 x 470k 2 watt
    2 x 470 ohm 2 watt

    Wires
    Black
    White
    Red
    (yellow)
    Blank buzz-wire
     
    Last edited: Jan 16, 2020
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  16. pleximaster

    pleximaster Well-Known Member

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    D1ADB89E-89D7-46A0-8DB7-BB73D242180C.jpeg


    Gathering another batch of parts for my own chassis. Will copy holes and layout from the old stripped chassis!

    One problem with these replicas is that they eat out my stash of old parts. Usually I miss a nut or a screw here... :) a socket there a wire over there ... But here with a replica it really empties my saved parts... :)


    plexi
     
    Last edited: Jan 16, 2020
  17. pleximaster

    pleximaster Well-Known Member

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    Jim with No One Amp! In the 80´s 2000´s and 10´s... Jim Marshall No One.jpg
     
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