My 45/100 Jh Clone

Discussion in 'Building the Classics' started by neikeel, Mar 28, 2018.

  1. neikeel

    neikeel Well-Known Member

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    As promised a new thread for this amp.
    Pics are a bit dark and from my phone, will try some better pics another day and some clips of different styles.
    I am very pleased with the amp 'straight out of the box'. I have found these amps take a while to bed in but this only has a few hours on it (thanks teenage son) and it is really sounding good, very much like a good vintage example - I often find the clones a bit stiffer, louder and lacking a lot of the extra harmonics and interest that a decent well set up vintage example has. A set of better than new testing Mullard ECC83s and nearly new GEC KT66s helps.
    The chassis, PT and OT are Marstran, choke is from Metro, plexi panels from valve storm, boards I made myself, selectors are original paxolin wafers, head cab is made by Chris Uff in Norfolk (I added the Vox vents to match those on Ser. 6503.) Logo is MG and the knobs are Scott type from Valvestorm. Filter caps are a mixture of NOS RS and Steve Marshalls repros. Coupling caps NOS mustards and resistors are PIhers. I used a green plessey coupler as per the JH and similarly the cement screen resistors. I stopped short of cutting and burning the cap board and did not get round to polishing the chassis before I built it.
    Unfortunately the 0.05uF snubber cap (600v RMS rated) died on full voltage testing (after full cap reform to spec) but can't say I notice its absence. Will fit another 1000v rated one when I find one suitable. I will take some quick and dirty clips when I get chance but working all of the Easter w/e so maybe a while.
     
    Last edited: May 14, 2018
  2. MarshallDog

    MarshallDog Well-Known Member Premium Member

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    Very very very nice build, gorgeous I must say. Cant wait to hear some clips of it.
     
  3. S.Marshall

    S.Marshall New Member

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    Nice build Neil! I still have some original Hunts NOS .05 1000v snubbers if you want to try another. Yours for the asking my friend.
     
  4. harleytech

    harleytech Well-Known Member

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    Very Nice Build !
     
  5. v846

    v846 Member

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    Neil,

    Now that's a beautiful recreation of 7026, great attention to detail down to the green Plessey & even the heaters are the right color.

    db
     
  6. neikeel

    neikeel Well-Known Member

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    It is not an immaculate build (see odd pink wire colours etc) but I wanted to get it finished and keep most of the original skinny pink wire for my restos. I did get a big metal film 1st dropper R but forgot to use it.
    Loathe to change anything now as it is spot on for tone
     
  7. v846

    v846 Member

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    Yeah if it sounds perfect best not to touch it, box it up & have some fun:)
     
  8. coldengray

    coldengray Active Member VIP Member

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    Great job Neil!
     
  9. Metroman

    Metroman Well-Known Member

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    :drool::drool::drool::drool::drool::drool::drool:"
    :naughty:
    :naughty::naughty::naughty::naughty::agreed::agreed::agreed::wub::wub::wub2::wub2:
     
  10. neikeel

    neikeel Well-Known Member

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    :)
     
  11. jensvonbustenskjol

    jensvonbustenskjol Active Member

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    Very nice indeed! Well done!
     
  12. Michael RT

    Michael RT Well-Known Member VIP Member

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    Amazing work my friend, I love it. :wub::wub2: :thumb:
     
  13. Kelia

    Kelia Active Member

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    Old thread but needed to say that yoiur build is beautiful !!
    I'm about to take the plunge and have my tech build me one !
    What made you choose the Marstran's over the Metro spec Heyboer ?
    I saw on Marstran page that you have a choice of secondary tap for 560vdc or 490vdc for todays tubes.
    Any thought on this ?

    Oh and have another question,.....some install the silver Rifa cans and others go for the black ones like on this one below from a LP forum member ,....are they the same or different ?
    https://www.mylespaul.com/threads/jtm-45-100.223991/

    Tx
     
  14. neikeel

    neikeel Well-Known Member

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    Thanks
    It is not perfect aesthetically because I decided to crack on and get it finished it sounds great and is not to be changed!
    The grey caps you see are RIFAs dressed up. The preamp can is an original RS reformed fully. I doubt it makes a lot of difference whether you use these or F&Ts. Both are good quality.
     
    Last edited: May 23, 2019
  15. BftGibson

    BftGibson Well-Known Member

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    Nice, that would be an enjoyable amp for sure. I have played my jtm45 cl more & more each week & seems between it jtm50 & jmp50 have really found the big full sound in that era vs all the other amps i have. Gain has come down as i learn how to play these amps better. 4 kt66 gotta sound huge !!
     
    Kelia likes this.
  16. Kelia

    Kelia Active Member

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    Thanks Neikeel !!
    Can you tell a little about your choice for Marstran instead of Metro 66 Spec Heyboer's ?
     
  17. neikeel

    neikeel Well-Known Member

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    I have used Metros in the past (pics on that site many years ago, the second 45/100 after Flames 1950 build) and got the Marstrans at a good price, I am always happy to use Brian's specc'd Heyboers, I doubt there is much difference between them. I have used a Merren 45/100 OT on an amp that Pleximaster featured in a Johan Seghborn video that also sounded excellent.
     
    Kelia likes this.
  18. Kelia

    Kelia Active Member

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    Thanks Neikeel!
     
  19. Kats

    Kats Member

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    Man, what great idea doing a repro of 7206 like that! Now on my bucket list. Great job!
     
  20. Exojam

    Exojam Well-Known Member

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    Neikeel,

    What are the components on the separate board for and what are the black components on that board?

    Thanks.
     

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