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Saturday, February 14, 2015

Alembic Stratoblaster

The Stratoblaster was originally built as an onboard preamp that could be mounted on a Strat in place of the normal output jack canoe. The gain was adjusted by a trim pot (so no external knob), but the circuit provided 3-14 dB of clean boost. It's a great simple circuit and can fit in a 1590a or you could build it into a guitar (for all you Grateful Dead fans out there).


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16 comments:

  1. SkarsoulFebruary 17, 2015 at 5:27 PM

    What is the labeled "4001"?

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  2. SkarsoulFebruary 17, 2015 at 5:52 PM

    doh! :)
    Thanks for the quick reply!

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  3. UnknownMay 21, 2016 at 11:57 AM

    for what is the gain 3 and gain 1/2 and how will i connect the output jack? thanks
    for the answer. :D

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    Replies
    1. Effects LayoutsMay 21, 2016 at 12:13 PM

      Those are the potentiometer lugs. If you're building it into a pedal, see the General build notes for how to wire it with a footswitch. If you're building it into a guitar the concept is similar to what's described there too. And Google is always helpful.

      Delete
    2. UnknownMay 21, 2016 at 6:35 PM

      thanks for the quick reply sir.

      Delete
  4. qrdMarch 1, 2018 at 3:54 AM

    What is replacement for 2N5457 is 2n5458 okay?

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    Replies
    1. Effects LayoutsMarch 1, 2018 at 9:47 AM

      That should be ok. Though you may need to adjust the bias (22k resistor going into the drain and/or the 12k off the source)

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    2. adminApril 6, 2019 at 12:44 PM

      what value to replace in that position, of I use 5458

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    3. Effects LayoutsApril 6, 2019 at 1:46 PM

      You’ll have to experiment and see. Maybe use a 50k trimmer to dial it in.

      Delete
  5. adminAugust 30, 2019 at 11:13 PM

    is it okay to change 1.5 uf to 1 uf?

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  6. bapFebruary 20, 2020 at 1:03 PM

    This comment has been removed by the author.

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  7. JDTMarch 30, 2020 at 8:54 PM

    Verified.
    Layout works but the 100 ohm resistor off of the output should be 100 Kohm. An anti-log pot, like on the GGG version, might have a better rotation.
    I substituted a J113 and a 1uF cap in place of the 2N5457 and the 1.5uF cap, respectively, but it still sounds good. I might lower the 68k resistor to 100 ohms (also suggested by GGG) and replace the output resistor with a volume pot.

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  8. Werther EllerbrockApril 11, 2021 at 12:03 AM

    Isn't 100Ω supposed to be 100K?

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  9. FunkManJanuary 24, 2022 at 12:19 AM

    Doesn't sound good in a Strat because its too bright. A unity gain buffer sounds better

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