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Webcor Reel to Reel conversion thread

Discussion in 'Shock Brother's DIY Amps' started by ArcticWhite, May 17, 2018.

  1. Jake Nelson

    Jake Nelson Tele-Meister

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    The problem is that it doesn’t have a 5v heater tap. Only the 6v.
     
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  2. ArcticWhite

    ArcticWhite Tele-Afflicted

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    Hah!
    I'm slow, but at least I'm dumb enough to ask the right question.

    I think I may do RobRob's switchable solid state rectifier.
    Are these the correct diodes to order for this project?

    upload_2020-9-28_18-20-46.png
     
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  3. Jake Nelson

    Jake Nelson Tele-Meister

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    Yep. 1N4007
     
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  4. ArcticWhite

    ArcticWhite Tele-Afflicted

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    In taking a look at the schematic of the GA-20T, I'm struck by the line of 0047uf caps in channel 2.

    Are these part of the tremolo oscillator?

    20200928_193047.jpg
     
    Last edited: Sep 29, 2020
  5. Jake Nelson

    Jake Nelson Tele-Meister

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    The oscillator is the 3 down below. The line of them is a low pass filter that only lets the the oscillations threw and not other unwanted noise.
     
  6. ArcticWhite

    ArcticWhite Tele-Afflicted

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    Anyone got a gut shot of a GA-20T with the board flipped over?
    I don't see those five 0047uf caps in series. Are they under the turret board? Doesn't seem like much room. What type of caps should I use here?

    1959-gibson-ga-20t-ranger-tweed_360_6494b7511f787d02173d0134dc0fa144.jpg

    20200929_225236.jpg
     
  7. Nickfl

    Nickfl Friend of Leo's

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    You should use a high voltage cap for the first in the string, the others can be whatever just.need to be able to take the signal voltage.

    In an amp from that era I'd kind of expect to see ceramic caps used there, but I don't know what Gibson used. I'd be surprised if they are under the board, but maybe.
     
  8. ArcticWhite

    ArcticWhite Tele-Afflicted

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    As they are in the signal path, should I use polyester, polypropylene or something other than ceramics?
     
  9. Jake Nelson

    Jake Nelson Tele-Meister

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    Lots more info on the GA-40 and that board is double sided so it could be. Going to be an interesting build.
     
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