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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.
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33 comments:

  1. GuilhermeMarch 14, 2015 at 2:22 PM

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

    ReplyDelete
    Replies
    1. dtgehringMarch 14, 2015 at 3:18 PM

      Here you go:

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

      Delete
    2. GuilhermeMarch 14, 2015 at 3:28 PM

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

      Delete
  2. AnonymousMarch 14, 2015 at 11:57 PM

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

    ReplyDelete
  3. dtgehringMarch 15, 2015 at 9:32 PM

    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.

    ReplyDelete
  4. RyanJanuary 13, 2016 at 9:53 PM

    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!

    ReplyDelete
    Replies
    1. Effects LayoutsJanuary 14, 2016 at 9:30 AM

      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.

      Delete
    2. wainer.said@gmail.comJanuary 21, 2016 at 4:53 PM

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

      Delete
  5. RyanJanuary 24, 2016 at 2:56 PM

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

    ReplyDelete
  6. AJFebruary 20, 2016 at 9:59 AM

    This comment has been removed by the author.

    ReplyDelete
    Replies
    1. Effects LayoutsFebruary 20, 2016 at 2:00 PM

      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.

      Delete
  7. UnknownOctober 9, 2016 at 10:21 PM

    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?

    ReplyDelete
  8. UnknownOctober 15, 2016 at 12:02 PM

    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?

    ReplyDelete
  9. JavierMarch 7, 2017 at 1:17 PM

    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! ;)

    ReplyDelete
  10. AndyMarch 11, 2017 at 4:44 AM

    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

    ReplyDelete
    Replies
    1. Effects LayoutsMarch 11, 2017 at 8:44 PM

      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.

      Delete
    2. AndyMarch 12, 2017 at 9:24 AM

      It's SmallBear always does good work. Thanks brother

      Delete
  11. DanApril 3, 2017 at 6:19 AM

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

    ReplyDelete
    Replies
    1. Effects LayoutsApril 3, 2017 at 10:04 AM

      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).

      Delete
    2. plushApril 4, 2017 at 11:45 AM

      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.

      Delete
    3. DanApril 5, 2017 at 9:25 AM

      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.

      Delete
    4. Effects LayoutsApril 5, 2017 at 9:45 AM

      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

      Delete
    5. DanApril 5, 2017 at 5:17 PM

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

      Delete
  12. windows95July 3, 2017 at 9:08 AM

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

    Thank you.

    ReplyDelete
  13. nasdnfnvounwonknasdoinAugust 24, 2017 at 12:46 PM

    Verified, built the "Cloven Hoof" version instead of using germaniums! Awesome sound, thanks for the schematic

    ReplyDelete
  14. Nathan MaruchJune 23, 2020 at 10:41 PM

    Hi there!

    I like layouting my PCBs (living in Brazil and stuff, I really have to be careful about component footprints, buying them online is a real hassle down here), so... Could you post the schematics as well? Thank you very much!

    ReplyDelete
  15. ClassicFuzzApril 11, 2021 at 2:28 PM

    Hey,
    I was just wondering, after reading the FSB Hoof thread, if the Hoof schematic might have slightly changed?
    1. Judging by this video by EQD they are now using MP38a transistor:
    https://www.youtube.com/watch?v=rVwuT-YFvPs
    2. I also realised that there aren't using any ceramic caps in the circuit anymore. Could it be possible that they changed them to higher values to increase the gain in order to use low gain MP38a's?
    3. The LED have changed as well from 5mm red to 3mm (clear) red.

    ReplyDelete
    Replies
    1. ClassicFuzzMay 6, 2021 at 10:25 AM

      Any ideas anyone? I would love to use my MP38a's, but am unsure about the overall gain.

      Delete
    2. Tim MikhailouskiMay 21, 2021 at 8:41 AM

      You can use MP38A's without any worries

      Delete
  16. Ismail cApril 18, 2022 at 5:55 PM

    I built this, it works but when I set the tone pot all the way up it cuts the volume all the way down, and if I set the tone pot all down I got no sustain. Tried changing pots bu it didnt help. Any help?

    ReplyDelete