JTM 45 Reissue . Anyone upgraded one ?

Discussion in 'Amps and Cabs' started by pm250, Mar 24, 2006.

  1. pm250

    pm250 Member

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    Just wondering if anyone out there has modded either a reissue Bluesbreaker combo or JTM 45 Reissue head with a Metro amp kit (or similar) and Mercury magnetics transformer ? Also what about swapping to KT66 output valves ? Speaker changes etc ? I`m interested what differences these changes actually did and were you pleased with the results ?
     
  2. JLee

    JLee Supporting Member

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    I've swapped to KT66s, changed speakers and installed a solid state rectifier in my Bluebreaker. KT66s will give you more midrange and a smoother breakup than the stock 5881s. I put in a solid state rectifier to give it a slightly faster attack and lessen the sag. If you are interested in KT66s I have a pair of Tung Sol RI KT66s for sale. $35 shipped. They have less than 10 hours on them. Reviews have been REALLY mixed to be honest with you. Personally, I found them to be similar to the Groove Tubes I had previously. Smoother high end though and a bit more low end, but similar tone to my ears. I'd like to try the Valve Arts so I'm selling these.
     
  3. jpage

    jpage Silver Supporting Member

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    Don't know whether or not you are planning on puchasing a used amp to rebuild or currently have one, but I know that Rockytop amps is blowing clones out right now--it might be worth a call...
     
  4. CAFeathers

    CAFeathers Member

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    I have a Marshall JTM45 RI and have done most of the mods listed on this website:
    http://www.raw-sewage.net/jtm45ri_mods.html

    I tried the Valve Arts KT66's and didn't like them. I am using NOS tubes now. I went with a Heyboer Output Tranny.

    Here is a pic of my JTM45 in it's custom made Mahogany/Flame Maple cabinet with matching 2x12. There were no speakers in the 2x12 when the pic was taken.
    [​IMG]
     
  5. Lance Long

    Lance Long Member

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    Chet,

    What a great looking set of wood!! Where could I get a similar set of head and speaker cabinets?

    Thanks,

    Lance
     
  6. CAFeathers

    CAFeathers Member

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    Lance
    Thank You. Because of some issues with the builder of those cabinets I can not recommend him.
    Do a Google, Yahoo, or similar search for Custom Amp Cabinets and you should come up with a few companies that do them.
     
  7. Lance Long

    Lance Long Member

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    Chet,

    Will do. Thanks for the recommendations. By the way, what wood is used in your cabinets?

    Regards,

    Lance
     
  8. Nativ H

    Nativ H Member

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    I bought a JTM45RI, gutted it and put in a PTP board, Marstran OT and PT, GEC's and Mullards and it sounds awesome. Brian makes some killer iron. I've also had two real block logo JTM45's and the RI sounds pretty close. Or course it doesn't have the vintage vibe, collectability, or pricetag, but it is a great players amp that can be reproduced if some drunk spills a beer in it sometime. FWIW, I think the GEC's and Mullards are a great part of the final tone, especially when driven at 450V with the Marstran iron.
     
  9. CAFeathers

    CAFeathers Member

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    Mahogany and Flame Maple.
     
  10. big mike

    big mike Moderator - EL34 Emeritas Staff Member

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    Bob Burt could do something I'm sure. I've not done any business with him, but many on this forum have.

    www.bobburtcabinets.com
     
  11. shakti

    shakti Member

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    If you plan on doing a complete makeover with new transformers, new PTP board and changed filtering, you're doing so much work that it's probably just as good to sell the amp and buy a Metroamp JTM45 kit. I am building one right now. It's very doable, a lot of fun, and costs 950 bucks. According to those who have finished their builds, it sounds amazing, way beyond the stock Marshall, especially with Sozo Mustad + caps.

    Of course, never skimp on the tubes...
     
  12. Tag

    Tag Gold Supporting Member

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    Just a word of caution. The stock production JTM45s sound GREAT. An "upgrade" may actually be a "downgrade" tonally speaking. I A/Bd a stock Bluesbreaker combo against a Blockhead JTM45 clone and a Marshall HW JTM 45, and HIGHLY preferred the stock Bluesbreaker. To my ear, it just had a sweeter tone and a smoother breakup. KILLER amp totally stock IMO.
     
  13. ericb

    ericb Silver Supporting Member

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    The Marshall JTM45 RI is MOST DEFINITEly a TOTALLY KILLER amp stock. I got mine over 10 years ago and played it stock for many years. ABSOLUTELY GREAT. I then did all the upgrade stuff (or RETRO stuff I call it) .. Actually Don Butler did it. The amp COMPLETELY XFORMED into another amp. Do I like it? I Love it and love it more than the stock version . IT's WAY different, way richer, breaks up earlier , and you can crank it to 10 and have an unbelievable sound. 1 of the best of all my amps. BUT I know others who had Don Butler do the mods, or Ted Breaux, or whomever and their brother does them , and they didn't like it as much. Seriously the whole amps changes. Either way to me it's a great amp... Also for you pcb lovers (haha) , this amp is PCB and BUILT really really really well...

    ERIC
     
  14. EADGBE

    EADGBE Member

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    Not to change the subject but does this amp like pedals? If so, which ones?
     
  15. Dendog

    Dendog Member

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    The amp likes overdrive pedals, any that I've tried worked great. In my opinion it does not like chorus/leslie type pedals. The sound out of that amp is so complex straight, that I find that adding those types of effects gets very muddy.
     
  16. Red Planet

    Red Planet Member

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    Well I went through this stuff several years ago and most folks suggested changing the Tranny's then Tubes then the Board. My experience has been that the Biggest Difference was the Tubes and the PCB. Not really the PCB itself but replacing all the cheaper components on it with the stuff that comes with Metro Amps Boards. To me I couldnt tell as much a difference in the Trannys as everything else. I've done a couple of these and not everything at once so I could tell the difference in each change.

    If I were you and you have one I would recomend Replacing the Board with the Metro Amps Turret Board Kit and get that finished. Once that is finished and you have the Amp working then start looking for some really good Tubes. I wouldnt recomend spending a lot on NOS Tube until after you have the amp fully functional.

    As far as the Trannys go I would Leave that for Last. Play the Amp with the Better Metro Parts in it and some really good Tubes then get back with me on how it sounds before you go yankin Iron out for no reason.
     
  17. Red Planet

    Red Planet Member

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    PS look for a good Layout Drawing cause Metro kinda Confuses you on that stuff.

    If you dont have an Amp you might as well just build one.
     
  18. sonnyblu42

    sonnyblu42 Member

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    I (or my tech) did this because I destroyed my OPT in my 2002 RI.
    Metro board PTP, Heybour Iron and all the Mods as previously listed, filter caps everything.

    Love it all... But, The Midrange control freq....

    I loved it in the RI. So I am searching for the changes I need to make, whatever resistor or cap we need to change to get the midrange tone control freq I miss.

    Has anyone else experienced this? If so what did you change?
     
  19. mikecat

    mikecat Senior Member

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    I modded a JTM45 Marshall reissue with the Metro Amp kit, and added Sozos and carbon comps, and the tone was still kinda lifeless because of the cheap sounding, one dimensional transformers.
    I put it back to stock and sold it.
    I bought a Metro JTM45 Marshall with Mercury transformers and love it, but I did modify it to be a 1987 Lead spec board, EL34 output tube section, but kept the JTM45 power section, tube rectifier, JTM45 choke, and p.t., but replaced the o.t. with a 1987 Plexi 50 Mercury, and the amp sounds AMAZING!!!! It's the real deal - also added a post phase m.v.
     
  20. mikecat

    mikecat Senior Member

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    search Ceriatone Amps, they have great wiring diagrams for that amp.:barf
     

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