Supro Thunderbolt Build

Discussion in 'Building the Classics' started by Timbo, Oct 6, 2018.

  1. Timbo

    Timbo Member

    Joined:
    Oct 29, 2009
    Messages:
    43
    Likes Received:
    26
    Hi guys, I've been a bit keen on these for awhile and some nice 6L6GC came my way.
    The original Thunderbolt S6420 is a simple circuit so that pleases me and the end result should see it rifting away to some awesome LED ZEP tones.
    I have modded the circuit as the original had a spare triode at the input stage.
    So looking through some of the other Supro schematics, I found the S6424 input a good fit.
    A neat mod at the input jacks will allow the original S6420 circuit to be played and the second channel S6424 circuit and a link jack to blend the two.
    Some of the component values have been changed to todays values and some are just what I have on hand.
    [​IMG]
     
    Jason Kennedy and Micky like this.
  2. Jason Kennedy

    Jason Kennedy New Member

    Joined:
    Jul 13, 2017
    Messages:
    15
    Likes Received:
    9
    Nice! Look forward to seeing how this turns out for you. Had a reissue supro thunderbolt for a short while, sounded great but unfortunately was faulty and had to be returned. Would be interesting in maybe tryin to build one myself someday.
     
  3. Timbo

    Timbo Member

    Joined:
    Oct 29, 2009
    Messages:
    43
    Likes Received:
    26
    Thanks Jason, a bit of progress...
    [​IMG]
     
    Jason Kennedy likes this.
  4. Timbo

    Timbo Member

    Joined:
    Oct 29, 2009
    Messages:
    43
    Likes Received:
    26
    Hi guys, Board completed.............
    [​IMG]
    I've done a VINTAGE mix with the components, just to capture some yesteryear MOJO.........
     
    Geeze and Rockcity like this.
  5. ampmadscientist

    ampmadscientist Well-Known Member

    Joined:
    Jun 26, 2014
    Messages:
    8,945
    Likes Received:
    3,618
    Location:
    On the wrong side of the tracks.
    The amp is basically low gain, until it is pushed into power tube distortion.
    Very similar to Led Zep tones.
    Is a good pedal amp because the preamp input does not break up easily...

    If you notice, Jimmy Page does not play dirty. He plays on the clean side, which makes this amp very similar tone.
     
  6. danfrank

    danfrank Well-Known Member

    Joined:
    Mar 5, 2015
    Messages:
    934
    Likes Received:
    470
    FYI: Screen resistors should be as close to the power tube pins as possible to avoid potential oscillation in the amp.some power tubes are worse than others. Pin 5 grid stoppers should be close also.
     
  7. Timbo

    Timbo Member

    Joined:
    Oct 29, 2009
    Messages:
    43
    Likes Received:
    26
    Thanks for the input guys.
    All wired up and ready to rock :jam:
    [​IMG]
    [​IMG]
    [​IMG]
    Power tubes cathode resistor is not in yet, It may need tweaking.
     
    Jason Kennedy likes this.
  8. AlvisX

    AlvisX Well-Known Member

    Joined:
    May 31, 2011
    Messages:
    3,231
    Likes Received:
    4,813
    Location:
    I-55 Corridor
    I had two T-bolts, a Supro and a Ward's Airline
    The interesting thing about the old ones , they had one half a 12ax7 just hanging there in space , doing nothing
    Not being one to leave well enough alone, I wired up that stray half . I put in a closed jack ,like a two hole Marshall ,to have hi and Lo inputs . The Lo was great for bass and the hi gave it a great tweed growl

    Good luck with the build, interesting idea
     
  9. ibmorjamn

    ibmorjamn Well-Known Member

    Joined:
    Nov 3, 2012
    Messages:
    5,703
    Likes Received:
    2,757
    Location:
    North
    Looks real good . I like 6L6 amps.

    I am going to build one that is loosely based on the Supro 24 but the triodes are parallel. Also using Russian 6P1P's for power. They are like 6bq5's . I have a nice small batch PCB for it to. Toroidal TX also.
    I need get busy on it.
     
  10. Timbo

    Timbo Member

    Joined:
    Oct 29, 2009
    Messages:
    43
    Likes Received:
    26
    Guys, The THUNDERBOLT BOOOOOMs.
    Fired up well with no problems.
    I'm keen to get it into it's cab to get a better idea of sound.
    [​IMG]
    [​IMG]
     
    Wildeman likes this.
  11. Timbo

    Timbo Member

    Joined:
    Oct 29, 2009
    Messages:
    43
    Likes Received:
    26
    Hi guys, Had a good day in the shed and knocked up the cab.
    [​IMG]
    I'm doing a bit of a test run to make sure everything fits.......
    As I said a trial run :redfaced
    I am really wanting to use the 15" speaker but it is only 4ohm and the OT is 15ohm.
    So the DUMMY 8" speaker is to make up the extra load, even though it still is only 11ohms as per the MM.
    I hope to get a stunt guitarist to give it a whirl.
    If it sounds crap I have only cut the opening in the baffle to take a 12" and the ply mounting the 8" is only tacked in.
     

Share This Page