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Direct Box

Discussion in 'Burnt Fingers DIY Effects' started by FosterF, Apr 29, 2012.

  1. FosterF

    FosterF Tele-Meister

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    Does anybody have a schematic for a DI box? I'm wanting to build a two in one DI (one mono for acoustic and the other stereo for click/loops) anybody?
    Thanks,
    -Foster
     
  2. FenderLover

    FenderLover Poster Extraordinaire

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    Balanced outputs?
    Isolation?
    Passive?
    Active?
    Equalization?

    There are many ways to go.
     
  3. FosterF

    FosterF Tele-Meister

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    Balanced outputs. Preferably isolated. Passive or at least be able to run on phantom. And no equalization. Just ground lift.
    OR whatever you think would be best for these two applications!
     
  4. FenderLover

    FenderLover Poster Extraordinaire

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    Isolation requires a transformer. They are pretty specialized and therefore expensive, but easy to use. The Jensen schematic requires a line level input because the transformer is basically a short to a guitar signal. While it is passive, the buffer circuits is not. It can be your choice, either a stand alone op amp circuit or a bypassed guitar pedal (that is not true bypass, like Boss).

    If you want to avoid the transformer, the output side of the Celtic schematic is a method for balanced output. For stereo, or dual mono, it's just more buffer circuits.

    Gyraf and AMZ are an examples of simple buffer circuits. 1-4 op amps in parallel make good buffers depending how long your cables are.

    I don't recall anything phantom powered, but running an op amp from a 12V or 15V zener in series with a resistor may work well. Some say that method is too noisy, but op amps have terrific CMRR specifications that have never caused alarm to me.
    AMZ_SuperBuffer.gif

    View attachment Jensen DI.pdf

    Splitter.jpg

    Celtic_DI.jpg
     
  5. FosterF

    FosterF Tele-Meister

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    The Celtic schematic looks promising! What would I need to change in order to make it stereo inputs that wouldn't have any bleed over?
     
  6. FenderLover

    FenderLover Poster Extraordinaire

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    Your simply build two of them. One right, one left.
     
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