Can I use 125BSE in place of 125B for output transformer?

Discussion in 'Shock Brother's DIY Amps' started by dantahoua, Sep 18, 2020.

  1. dantahoua

    dantahoua TDPRI Member

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    Hello!
    I bought 3 years ago all the stuff to make a Bassman Micro. I finally have the time to make it (and I choose to make the LTP one). I'm not that good with all the power part of the amp (but very good with the Preamp part :) ).
    I just notice the Output transformer I received 3 years ago is the SE one and not the regular one.
    Can I use it in the Bassman Micro? I was about to wire the black and green to the speaker jack (8ohm) when I noticed it is not the same color @robrob was describing in the "tutorial"...
    Thanks for your time! :)
     
  2. zook

    zook Friend of Leo's

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    They are different in that the `125B is for a push-pull circuit and the 125BSE is a single ended OT.

    That being the case, they can not be substituted for each other.
     
  3. dantahoua

    dantahoua TDPRI Member

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    Gosh... I'll have to order a good one and this one is no use to me... :(
    There is no way I can use it with this layout?
     
    Last edited: Sep 18, 2020
  4. tubegeek

    tubegeek Friend of Leo's

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    The 125BSE has two primary connections: B+ and plate. You need 3 for a push-pull amplifier: B+, Plate (push) and Plate (pull.)

    Game over. Sorry!

    Save the 125BSE and make a Champ someday, it'll come in handy.
     
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  5. radiocaster

    radiocaster Poster Extraordinaire

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    You could if you rewire the phase inverter as a regular preamp stage, and the power triodes in parallel.
     
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  6. dantahoua

    dantahoua TDPRI Member

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    Very interesting! Would love to see how to do that. But anyway, I'll follow @tubegeek suggestion and keep it for a small champ or something like that SE amp. I'm a guitar maker, not an amp maker, this amp will be just for my shop to test my guitars! I do not want to spend that much time on it. :)
     
  7. dantahoua

    dantahoua TDPRI Member

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    Would go with the 125B(5W) or 125C(8W) knowing that I'm more a peamp overdrive than a power amp overdrive guy and I'll pair this small amp with another 22W 6V6 amp for stereo (but at very low volume). ? And I will use a 12BH7 as power tube and I play baritone guitar. :)
     
    Last edited: Sep 18, 2020
  8. tvas22

    tvas22 Tele-Meister Silver Supporter

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