Like Christmas Morning... Can't wait to open it up!

Discussion in 'Shock Brother's DIY Amps' started by ArcticWhite, Aug 4, 2019.

  1. jimdkc

    jimdkc Friend of Leo's Silver Supporter

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  2. ArcticWhite

    ArcticWhite Tele-Holic

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    That's it!
    I noticed last week that I had made a couple of errors in my schematic, but I hadn't gotten around to fixing them.
    Now I don't need to. Thanks!
    I'm still trying to figure out where a vibrato switch though. This vibrato circuit seems to be grounded only through the intensity pot...

    So maybe it goes on the wiper of that pot?
     
    Last edited: Aug 19, 2019
  3. D'tar

    D'tar Friend of Leo's

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    Kudos to you! That is not an easy task and I know how many versions it takes to get to a legible logical schematic. Well done.

    [​IMG]
     
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  4. ArcticWhite

    ArcticWhite Tele-Holic

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    Thanks D'tar. I did make a couple of errors. Was fixing them when Jim found the official version.
     
  5. ArcticWhite

    ArcticWhite Tele-Holic

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    Well, I have a plan now, and parts ordered, so I started building a cabinet while I'm waiting.

    For now, I'm keeping the circuit pretty close to the original schematic, with the exception of inserting a guitar type input jack instead of the microphone.
    The input looks like this now.

    20190825_225804.jpg

    And it sounds amazing.
    The tremolo on this thing is incredible. It's super deep and will break up on the pulses. Very three-dimensional and seems to add a nearly indefinite sustain.

    The flute and strings settings are basically a treble and bass preset. I'm going to put a 1 Meg pot between them so I can range between the two extremes. I may end up with a Fender type tone stack, but this one is weird and very cool.

    Here's the cab I started building today.

    20190825_185152.jpg

    It's going to have a sloped face, and a horizontal orientation - like a vintage 50's tabletop radio.

    20190825_225507.jpg

    20190825_225546.jpg

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    I'm messing around with speaker grill designs.

    20190825_225836.jpg
     
  6. ArcticWhite

    ArcticWhite Tele-Holic

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    Help Please.

    Where should I put the interrupting footswitch jack for the vibrato?

    20190915_085643.jpg
     
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  7. ArcticWhite

    ArcticWhite Tele-Holic

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    Finished this little guy a couple of weeks ago and really enjoying it. I've ordered some matching knobs but otherwise it's complete.

    20191129_221237.jpg

    I wound up putting in a traditional cathode biased input circuit, but what really makes this amp special is the master volume, and the completely incredible tremolo.

    Baffle is 3/8 birch and sloped back 7 degrees. Southern yellow pine cabinet.

    20191129_221301.jpg

    The amp puts out just 7.5 watts, but the variety of tones available are almost limitless. The master volume and volume allows me to produce crunchy distortion, or cleans at the same volume.

    I mimicked the TV style speaker hole on the back panel.

    20191129_221212.jpg

    The tremolo is simply nuts.
    Incredibly rich and 3 dimensional. And with the intensity maxed, out it oscillates the volume to zero. Crazy. It sounds like a rack effect.

    20191129_221221.jpg

    I'll post some audio/video soon.
     
    Last edited: Nov 30, 2019
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  8. Paul-T

    Paul-T Tele-Meister

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    that looks really cool! I like the supro-style speaker cutout and you've done an amazing job of cutting out the control panel opening.

    One day I'll be able to understand how that tremolo works. Tell us if you have a moment.
     
  9. FenderLover

    FenderLover Poster Extraordinaire

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    A little late to the thread, but where did you put the switch?

    I noticed on your factory schematic that '*R21' has a note saying it is factory selected for one speed. This is where you can look at the Vibro Champ schematic and add the Speed and kill switch in the same place on yours.
     
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  10. ArcticWhite

    ArcticWhite Tele-Holic

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    Thanks, I had already put the speed pot in that location. I put the footswitch ground in somewhere nearby. Can't remember exactly where, as I located it by trial and error. I tried the Vibro-Champ spot and it caused weird noises.
     
  11. ArcticWhite

    ArcticWhite Tele-Holic

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    Here's what I ended up with. It's pretty similar to the original amp, but I added a Fender tone/volume stack, some bypass capacitors, and guitar input. don't know exactly how the tremolo works, but this circuit is way different than others I have seen. None of the components run to ground the way the Vibro-Champ does. That bus at the bottom of the schematic is not a ground. It all goes to the intensity pot wiper.

    20191130_222604.jpg

    20191106_212318.jpg

    20191110_214917.jpg
     
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  12. jonrpick

    jonrpick Friend of Leo's

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    Completely missed this thread. Great project! Love the end result!
     
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