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.

Monday, June 8, 2015

Zvex Fuzzolo

The Fuzzolo is one of the newer Zvex designs in a 1590a box. It's a stripped down Woolly Mammoth with a SHO added to the end, so it's got a huge fuzz sound. In production versions, there's a moveable jumper internally to go between active and passive pickups. You could use a SPDT switch to accomplish this, and make it easier to switch between the 2 modes, or you could eliminate the 2 input resistors (750Ω and 39k) and use a 50k pot as a pre-gain control. The PW (pulse width) pot pans between a square wave and a wide/narrow pulse width. Like the original, this should fit nicely in a 1590a enclosure.



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30 comments:

  1. Giovane SoaveJune 26, 2015 at 11:52 PM

    Hey man, great layout. Where did you found the fuzzolo schematic?

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    1. dtgehringJune 29, 2015 at 9:21 AM

      Found it over on the Tagboard Effects forum:

      http://guitar-fx-layouts.42897.x6.nabble.com/Zvex-Fuzzolo-td20891.html

      Delete
  2. AnonymousJune 29, 2015 at 7:10 AM

    Lin or Log ?

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  3. AnonymousAugust 31, 2015 at 2:54 PM

    It works but i guess PW knob is backwards :D I didn't measured 2N3904s but when i used them for Q1 and Q2, pedal had much more gain than the videos, so i decreased 100uF that connects to the PW knob to 22uF and it lost all the gain and became really gated. I changed Q2 to BC239C (396hfe) and it became really gainy again. At last i increased 22uF back to 100uF and changed Q2 to BC108C which has 102 hfe (odd i know, i measured it just like germanium transistors) and now, the pedal sounds just like the PGS demo. Thank you very much for the layout

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  4. AnonymousSeptember 14, 2015 at 1:32 AM

    i have an issues regarding this pedal. i built it with all the components but as i plugged it in there is too much gain and a humming sound..

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  5. AnonymousSeptember 14, 2015 at 2:59 AM

    there is a trace cut error in the diode, base from the schematic of ciaran haslett..

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    1. dtgehringSeptember 16, 2015 at 10:28 AM

      Not sure what you're referring to. The part of the circuit with the diode is just the standard Zvex SHO and the 9.1v Zener goes from source to gate of the MOSFET.

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  6. AnonymousSeptember 15, 2015 at 3:05 AM

    this is a good fuzz but my built is soooo damn buzzing.. what is the cause for this?

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  7. dtgehringSeptember 16, 2015 at 10:34 AM

    You might try and use lower gain transistors as suggested above. Also upping the value of the power filter cap (100uF cap on the left side of the board). This effects is basically a simplified Woolly Mammoth and a SHO combined, both of which have plenty of gain on their own. It's not all that surprising that combined it'd be A bit noisy.

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  8. AnonymousSeptember 16, 2015 at 8:22 PM

    thanks for your reply man.. i'll try to debug it later... i made your magnavibe, guitar di box and a bearfoot blueberry bass overdrive, it works like a charm!!! godbless..

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  9. donostilongboardersSeptember 21, 2015 at 3:54 AM

    what does passive in and active in mean? i have never heard passive in :S

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    1. dtgehringSeptember 21, 2015 at 9:48 AM

      Passive pickups are regular guitar pickups. To paint with a broad brush, just about anything that's not made by EMG would be passive. haha

      http://proguitarshop.com/andyscorner/pickups-explained-active-vs-passive

      The reason there's the switch is because of the differing output impedances between active and passive pickups.

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  10. donostilongboardersSeptember 25, 2015 at 5:27 AM

    This comment has been removed by the author.

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  11. AnonymousSeptember 28, 2015 at 7:59 PM

    too much noise.. i made your version and created a new vero layout by ciaran haslett its all the same.. what should i do to get rid of that?

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    1. dtgehringSeptember 29, 2015 at 9:34 AM

      Did you try using lower gain transistors, as suggested in the comments above?

      Delete
  12. AnonymousNovember 21, 2015 at 10:58 AM

    Where is the Out point on the vero/pcb layout?

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    1. Effects LayoutsNovember 21, 2015 at 12:52 PM

      Volume lug 2.

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    2. UnknownDecember 8, 2015 at 7:06 AM

      Before it hits the vol pot,the output signal is going through the wire marked vol 3,..once you've soldered the pot the output goes out through vol 2
      So pre pot vol 3...after pot vol 2.

      Daniel Allan

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  13. UnknownAugust 19, 2016 at 11:56 AM

    If you want to build this, definetely order some alternative transistors for Q2, also if you don't need to squeeze this into a 1590a enclosure, sockets for the transistors will make your life a lot easier.
    Just built this and the PW knob doesn't work, time to order a multimeter I guess

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  14. UnknownMarch 5, 2017 at 5:44 AM

    Well I did it, and it works fine, thanks for the layout !
    Now the Volume is very low and I don't know why, I measured knob volume values and passive in enter resistance values, they are ok, i looked for a mistake in other resistance and I don't find any.
    So is there someone with the same issue or with an idea to solve it please ?

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  15. brunoJuly 18, 2017 at 12:13 AM

    Hi how can i put a fuzz control? ¿wich resistor should turn a potentiometer? thanks!

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    1. tipekApril 8, 2018 at 3:40 PM

      ad a 1-2K pot uder the 100u kapacitor, on emitor Q2 tranzistor, look zvex mammoth drive kontrol ,

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  16. tipekApril 8, 2018 at 3:51 PM

    hi , i build thhis layout, I had a few problems,
    I used transistors 2N3904 with hfe 236-240,
    the pedal was very noisy when I did not play guitar,
    the noise gate did not work until the 80% PW driver was set,
    the pedal was unusable,
    I will try 1M pot instead of 500K for PW driver,
    I measured the range when the noise gate works,
    I ended up combining a 500K pot + 470K resistor in series to a potentiometer,
    i tried other transistors with lower hfe but then shortered sustein and noise did not hurt,my pedal does not play as fuzzolo but as BUZZOLO :D :D very buzzing sound, i aded a 10K volume pot,

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  17. Jordan S.April 23, 2018 at 2:45 PM

    This pre-gain control 50K pot, how to connect?

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  18. rlbJuly 5, 2020 at 8:23 PM

    Great fuzz,but the resistor next to the mosfet (51K) is wrong,the correct value is 5k1 or the pedal gets very noisy and loud.
    https://www.freestompboxes.org/viewtopic.php?f=7&t=24986&p=263538&hilit=fuzzolo&&sid=e64932bd3f8096f4c586386fa33b32a1#p263538

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    1. trippaOctober 27, 2020 at 9:56 AM

      the image is wrong. swap on that schematic the 51k and 5.1k and it works like the original whit no noise and good waveshape ;) thanks for mirroring the problem

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  19. trippaOctober 27, 2020 at 9:54 AM

    error found on the 51k that connect the collector of q1 to base of q2. in fact is a 5.1k
    I put a 10k and it work great to but with less square wave.
    5.1k
    20k
    51k
    this is the exact order for make it work!!!! not hfe problem, very transistor works fine but resistor wrong on pcb !!!

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    Replies
    1. AlexSSeptember 4, 2021 at 2:57 AM

      51k would make more sense at the Fuzz Face type beginning, and 5k1 matches the S.H.O. used on the last boost stage.

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