JTM Clubman New 18 Watt Amp With Vintage Parts

Discussion in 'Building the Classics' started by pleximaster, Nov 20, 2019.

  1. pleximaster

    pleximaster Well-Known Member

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    Made this 18 watter for Thomas Hinson (Tom vintage here on the forum)

    I made it out of old parts that Tom and I had. Wanted to make the JTM amplifier Marshall never made... :)



    plexi
     
  2. Guitar-Rocker

    Guitar-Rocker Well-Known Member

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    Looks like the amp has a 1974 based theme that was started with, and the Normal side changed to JTM? Also looks like a EZ81 rectifier and maybe EL84 output tubes?

    Very nice job, by the way !
     
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  3. neikeel

    neikeel Well-Known Member

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    Very nice
    Looks and sounds very similar to my 18watters, although I can't see what has been done off the board!
     
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  4. shakti

    shakti Member

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    Agree, very nice sound. But it appears to be stock 18w into a 4x12, unless there are mods outside the board that we can't see. The old components and transformers is the key here. A good 18w is so fun and effortless to play!
     
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  5. pleximaster

    pleximaster Well-Known Member

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    Thanks
    Its mostly minor value changes here and there, more to get the sound and feeling towards JTM vs JMP
    Not so much schematic wise.

    Then Tom plays a lot of Stratocaster so I used my Strats a lot in the design and while tweaking it

    Johan joked with me (I am a 98% Les Paul user) and said to me “You tried to designed an amp that makes a Stratocaster sound like a Les Paul...” Probably kind of true!

    We will make a build video on Johan’s channel, Johan Tom and I!

    Originally the idea was to just make an 18 watt clone in head form so you could use different cabs more easily then a combo

    It sort of evolved a bit from that and then a lot of trial and testing of different components

    Neither of the transformers were the ones originally thought to be used. First MT was changed so it hand be wired for Toms 110 voltage in the US (haven’t tried that yet... ) and the first OT (older version of the RS transformer) was great sounding but had serious “vibrating/singing” issues (core acted like a speaker coil) and I replaced it with this one as singing transformers often turn bad as the coil wiring vibrates agains each other or the coil and insulation breaks

    Tremolos have always been an Achilles heal for me when repairing old Marshall’s and I made a few changes. It’s pretty massive perhaps a bit too much for purists...

    Plexi
     
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  6. Chris4189

    Chris4189 Well-Known Member

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    Schematic or it didn’t happen ;) I thinks it’s a great sounding amp! Well done sir!
     
    Last edited: Nov 20, 2019
  7. tomsvintage

    tomsvintage Well-Known Member

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    Excellent work pleximaster :) :) !! It sounds just as nice as it looks !! I am looking forward to using this great amp through my alnico loaded 4 x 12 !!
     
    Last edited: Nov 20, 2019
  8. shakti

    shakti Member

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    The tremolo on my 18w build (original chassis and OT, old stock parts) has the same hypnotic quality. Very cool tremolo on these even in stock form.
     
  9. neikeel

    neikeel Well-Known Member

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    Over the weekend I will post pics of my 18w Trem head built earlier this year with NOS parts. I am bad because I put a gold block logo on mine. Glad that OT sounds good shakti:)
     
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  10. ricksdisconnected

    ricksdisconnected Well-Known Member

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    who is playing?
     
  11. neikeel

    neikeel Well-Known Member

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    It is Johan S isn't it?
     
  12. pleximaster

    pleximaster Well-Known Member

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    Yes of cause! :)
     
  13. ricksdisconnected

    ricksdisconnected Well-Known Member

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    did not know he was a member here.
     
  14. pleximaster

    pleximaster Well-Known Member

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    I don´t know if Johan Segeborn is a member here or not. But we have known each other for years and he has demoed many of my Marshall amps and cabs.

    At some points people have had him and me mixed up... :)

    plexi
     
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  15. danfrank

    danfrank Well-Known Member

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    Hi Pleximaster!
    I haven't been on here in a while but I just got through Johan's video on this amp... Great job! The amp sound terrific! I think a lot of people will be into this amp because it's a popular size for people to use.
    Great work!
    I hope you are doing well.
     
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  16. ibmorjamn

    ibmorjamn Well-Known Member

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    He is a member here , I have not seen him here lately. Nice amp , I am not a Strat player and not in to the tremolo amp but that could be another gain stage instead I suppose right ?
     
    Last edited: Nov 30, 2019
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  17. pleximaster

    pleximaster Well-Known Member

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    Hi Dan!

    How are you? We should ha a chat!

    Johan and I will make a build video of this amp like the one we did with the Marshall 200 the Pig Major.

    About the Marshall Pigs I have another one in the loop of being restored, haven’t finished it (probably had it for the last too years, missing some parts and time, I am also instructed by my doctors not to lift heavy... ) must finish it someday

    How are your builds and restorations going?

    Plexi

     
  18. pleximaster

    pleximaster Well-Known Member

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    I saw Johan again yesterday gave him some old checker board cloth to regrill an old cab. We are good friends

    I guess he does not have so much time to hang around the forums as he is so dedicated to his great YouTube channel

    The Clubman doesn’t have an extra gainstage it actually pretty close to the original. It is more cherrypicked values and selection of parts that are changed.

    Plexi


     
  19. neikeel

    neikeel Well-Known Member

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    Not hijacking, just sharing the premise:
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    Bare chassis and head cab from StevesUK (part in trade). Well made, although I might have had the cab made not quite as tall if I had drawn it up myself. As you see I used correct original RS transformers and NOS parts (apart from the electrolytics). I used the ceramic discs a little more than I would normally and they definitely add some grit and interest when you drive it.
    It is, as nearly everyone else claims about a new build, sounding fantastic, just like the clips made by Johan above, and my 2x12 combo. Sounds pretty huge through any of my 4x12s.
    Interestingly the little combo it sits on is based on a Ceriatone 18w in a Reason 1x12 cab. I built it with a Scumback G12H55 (Weber era) and it sounded pretty good but I dropped in a G12M modern 16ohm greenback and it has really come alive, maybe because you can drive the amp a little harder with the less efficient speaker. EF86 channel is noisy (despite various tweaks) and, when I get time I will sub a 12AX7 in the previous EF slot, cascade it for SLO type gain and be done.
    Pleximasters post and Johan's clips demonstrate how good that first design and build concept by Marshall (pinched from Watkin's??) was.

    This is the layout I used:
    [​IMG]
     
    Last edited: Dec 1, 2019
  20. Guitar-Rocker

    Guitar-Rocker Well-Known Member

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    Fantastic looking build, thank you for sharing the photos.
     

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