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.



22 comments:

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

    ReplyDelete
    Replies
    1. Found it over on the Tagboard Effects forum:

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

      Delete
  2. Replies
    1. PW is Lin (B) and Volume is Log (A).

      Delete
  3. 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

    ReplyDelete
  4. 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..

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

    ReplyDelete
    Replies
    1. 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.

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

    ReplyDelete
  7. 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.

    ReplyDelete
  8. 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..

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

    ReplyDelete
    Replies
    1. 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.

      Delete
  10. This comment has been removed by the author.

    ReplyDelete
  11. 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?

    ReplyDelete
    Replies
    1. Did you try using lower gain transistors, as suggested in the comments above?

      Delete
  12. Where is the Out point on the vero/pcb layout?

    ReplyDelete
    Replies
    1. 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

      Delete
  13. 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

    ReplyDelete
  14. 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 ?

    ReplyDelete