This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Friday, July 15, 2016

Ampeg Scrambler

It's Fuzz Friday time again, and this week I give you the Ampeg Scrambler. This one's a pretty rare one, even back when it was originally made in the late 60s. It's a pretty crazy octave fuzz with a clean blend. Originals used 2N5306 for Q1, 3, and 4, and a BC169 for Q2, but those could be difficult to source, and it works fine with modern equivalents (mind the pinouts if using original transistors). If you want to add a master volume control, use a 100k pot (adjust to taste) and wire lug 3 to the Out pad of the board. Lug 2 is now your output, and lug 1 goes to ground. This sounds pretty cool on bass as well as guitar.


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14 comments:

  1. UnknownJuly 15, 2016 at 1:12 PM

    schematic?

    ReplyDelete
    Replies
    1. Effects LayoutsJuly 15, 2016 at 1:16 PM

      google?

      http://www.maxvolmag.com/wp-content/uploads/2013/04/Ampeg-Scrambler-Schematic.png

      Delete
    2. UnknownAugust 7, 2016 at 3:58 AM

      excuse question. this functional layout?

      Delete
    3. UnknownAugust 7, 2016 at 3:59 AM

      excuse question. this functional layout?

      Delete
  2. Giovanny SantosOctober 25, 2016 at 7:55 PM

    Not is working for me :/ Only a buzz sound on the amplifier.

    ReplyDelete
  3. Giovanny SantosOctober 25, 2016 at 10:18 PM

    I got 9v measures on the pot pads. Seems i have a short, no? But i checked my board for 4 times and not found the short '-'

    ReplyDelete
    Replies
    1. Effects LayoutsOctober 26, 2016 at 11:23 AM

      Yeah, I would think something's shorting. Could be a bad component somewhere

      Delete
    2. Giovanny SantosOctober 26, 2016 at 4:20 PM

      I think it is not the problem, all my components are new. I already did some tests and could not find the problem right now. This layout is checked? Thank you a lot.

      Delete
  4. Giovanny SantosOctober 29, 2016 at 10:55 PM

    Layout checked! Working fine! The mistake was mine, i wired wrong the transistors (I used 1n5302 instead the MPSA14, so i forget to change the terminals... But now all is working fine. I had a trouble on the texture pot. It was not working, but i found a way. I removed the pot and jumped the terminal 2 and 1. Removed the 8k2 resistor and wired up a A500k potentiometer with a 1k resistor in series with his terminal 1. Working very fine the effect, i liked a lot. :)

    Let me know any questions.

    ReplyDelete
    Replies
    1. AgustínMarch 1, 2018 at 12:50 PM

      Giovanny it cant work for me and i Did all your modifications
      Any advise?

      Delete
  5. AgustínFebruary 27, 2018 at 1:07 PM

    Anyone knows if this pedal works?

    ReplyDelete
  6. UnknownNovember 18, 2018 at 3:02 PM

    Worked fine at first try!
    Add some good dirt to your bass.

    Used:
    BC517 instead of MSPA14,
    2N3904 instead of 2N5088.
    Sounds great.

    ReplyDelete
  7. ZZOYDMarch 11, 2019 at 1:55 PM

    mine work excelent too! Used:MSPA14, 2N5088.

    ReplyDelete
  8. Pabloc82September 12, 2019 at 2:31 PM

    Hi, I did it and it works really well.
    My question is if you can change the C1(10n) to a higher value to increase the bass?
    What value do you recommend?

    ReplyDelete

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