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.

Saturday, March 14, 2015

EarthQuaker Devices Hoof

In honor of it being Pi Day, I thought a Big Muff layout would be appropriate. While not an EHX Muff, the EQD Hoof is a BMP variant. It uses germanium transistors as well as LEDs in place of the typical silicon diodes in the 2 gain stages. It also has a Shift control, which allows you to boost the mids typically scooped in the standard BMP. Pots can be board mounted from the solder-side of the board using right angle PCB pots.



If anyone want to make the Cloven Hoof, use 2N5089 for Q1 and 4, use MPSA13s instead of germaniums for Q2-3, replace D3-4 with 1N4148s, and remove the 470pF cap by Q2.

28 comments:

  1. Hey buddy, what happended to the WTF Fuzz post? I can't find it!

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    1. Here you go:

      http://effectslayouts.blogspot.com/2014/12/rockett-wtf.html

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    2. oh, thanks! I couldn't find it using the search function!

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  2. Hi, Q2-3 is a 2n1308, right? this blog is awesome, thanks for share your layout's.

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  3. Thanks man! Yes, 2N1308, though any higher gain germanium transistors should work. I've seen a few Hoofs with Russian MP series germs in Q2-3 as well.

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  4. Which way is the proper orientation for the LED's? Square pads usually indicate positive, but this clashes with the outlines you have of the LED's.

    Thanks!

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    1. Square pads indicate positive side in polarized capacitors. For diodes they indicate the cathode. Not sure if that's traditional circuit board methodology or not, it's just what made sense in my head.

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    2. Yes is correct Square side and always positive side. This layout has already been verified?

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  5. Verified! Thanks for clearing up my confusion on LED's.

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  6. This comment has been removed by the author.

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    1. Not for the LEDs on the board. For the on/off indicator LED you would, yes. Check out the off board wiring diagram in the General Build Notes tab.

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  7. That would be nice to have a switch for germanium and silicon, so we have this pedal an a stock Big Muff, can you make that PCB?

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  8. That would be nice to have a switch for germanium and silicon, so we have this pedal an a stock Big Muff, can you make that PCB?

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  9. Verified!
    It sounds amazing, very rich and sophisticated muff sound... articulated, but with less bass or bottom end that my standard big muff... maybe can be tweaked for more lows, or maybe change some pot value on Tone or Shift...

    http://matacerdos.com.ar/DIY/Hoof_01.jpg
    http://matacerdos.com.ar/DIY/Hoof_02.jpg

    Thank you very much for the work you do here!
    I can't wait to build the Cloven Hoof now! ;)

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  10. I used SE4010 Fairchild Q2 Q3 Transistor, HFE around 180 and sound sounds pretty good .... now it's wait germanios to see if there is much difference.

    Will this transistor work well on Q2Q3?
    NPN Hot Germanium For The Big Muff
    http://smallbear-electronics.mybigcommerce.com/npn-hot-germanium-for-the-big-muff/

    or
    ETCO NPN Germanium 2N1306
    http://smallbear-electronics.mybigcomme ... um-2n1306/

    thanks

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    1. I would trust SmallBear if they say they'll work in a Big Muff. Looks like the hfe of those is over 200. If you got it to work with a 180 hfe transistor, the 200+ ones should be fine. Transistors typically don't make too much of a difference in a big muff circuit. In this case, as long as it's a higher hfe germanium it's going to sound very close to the original.

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    2. It's SmallBear always does good work. Thanks brother

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  11. Hi guys, does somebody know what kind of MP Russian series transistors were used in this pedal as well?

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    1. Not sure what MP ones they used, but some GT404s might be good candidates with hFE in the mid 200s. They're BCE pinout though (and they're also massive).

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    2. Hi!
      404s won't be ok since they are quite unstable and have very high leakage.
      Need good russian npn with decent leakage - go for MP38A.

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    3. yes, I have them both, but I just was wondering about the originally used transistors :). Thank you.

      P.S how does the leakage affect the sound? I never understood.. recently I made the candy apple fuzz with GT404B. I tried all my gt404s and I didn't mention any huge sound difference.

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    4. The 404s I have have been pretty consistent. But I'm sure that's not true across the board. Leaky transistors leak current making it harder for them to conduct and work correctly in a circuit. On rare occasions leaky transistors can be to your benefit. (an example being the original Maestro FZ-1). If you're wanting to test leakage, check out this layout and the linked article:

      http://effectslayouts.blogspot.com/2016/02/transistor-tester.html

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    5. Oh, thanks. I've read this before, but couldn't figure it out that time. Now I understood :D

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  12. Hi. What exactly is the '4001' component on the lower right part of the board next to the 100uF capacitor?

    Thank you.

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    Replies
    1. That's the polarity protection diode. 1N4001

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