Sunday 10 December 2017

Madbean Zombii / ZVex Fat Fuzz Factory

Tweaked Mark's original compact layout according to the info i found on the fat mode switch. Should be good to go.

29 comments:

  1. Thanks miro. I was going to try and etch one from the perf/pcb blog but this us much easier. Ill bang it together tonight and let you know

    ReplyDelete
  2. So the fat thing here is a sort of feedback loop with a 10 uf cap and 1M resistor in paralel, right?
    Time ago I tried something to get my original unit fatter, but was a total failure...

    ReplyDelete
    Replies
    1. Nope. The 1M just won't let the bigger cap have any signal trough it. Once that is shorted with a switch, the 0,1µ and 10µ are in parallel, totalling at 10.1µ. Point of the 1M is to prevent noise from flicking the switch.
      +m

      Delete
  3. looks great! The original has a 3-position switch (on-off-on) though. I built one recently, but can't remember which caps I ended up with...

    ReplyDelete
    Replies
    1. Was not aware of that. This "fat mod" was the only documentation i've seen. One could easily take the original layout and take the 100n cap to a DPDT on-off-on switch with two additional caps.

      ...so basically this layout is quite unnecessary :)
      +m

      Delete
    2. Would you remove that 1M and switch the 100n cap? Or would there be 2 switches? Is this what Wannes G mean't http://effectslayouts.blogspot.com/2016/03/zvex-fat-fuzz-factory.html

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

      Delete
    4. I just used one switch (SPDT on-off-on), each side placing an additional cap in parallel with the 100n. I started from the original layout on this site, so no extra 1M in there.
      My caps were probably a 470n and a 3u3, or something similar. I gave the pedal away, so can't check anymore.

      Delete
    5. I can't seem to get it to do that really gated sound. The typical FF squeals etc. Whats the likely culprit?

      Delete
  4. Great layout, cheers.. Does anyone know anything about the lucky 7 fuzz factory? does anyone have the layout for that?

    ReplyDelete
  5. Thanks for the killer layout Miro! She is verified. First fuzz factory I have built...weird. Only have one question. Is the fuzz control very subtle? Otherwise all the controls work well. Good fuzz, cleans up and is versatile!(Q1-2n3904 hfe 385, Q2- Ge Russian hfe 57, Q3-generic Ge hfe 147) Tried a few transistors per online discussions and these worked well. Have a great day! RAWK! \m/

    ReplyDelete
    Replies
    1. From the Fuzz Factory I built a long time ago I say yeah it's subtle! I basically either set it to 1 or 10! Sometimes 7ish if there's too much noise. With the Stability down it becomes more useful to tweak though.

      Delete
    2. right on THANKS! then this functions perfectly.

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

    ReplyDelete
  7. So is the fat switch SPDT or SPST because im not seeing where solder the third lug. Thanks

    ReplyDelete
  8. There is a mistake on this layout. The 5.1K needs to be to the collector of Q3, not the base.

    The original fat switch is a 3 position although no one online seems to know for sure if it's on-on-on or on-off-on or what caps are used.

    ReplyDelete
  9. Where does the 3rd stab pin go?

    ReplyDelete
    Replies
    1. The Schematic connects pin 2 and 3 of the stab control together

      Delete
  10. Thank you I'll give it a go

    ReplyDelete
  11. I have made some tests and fat capacitor (10uF) has reversed polarity. It sounds like Fat Fuzz Factory once (-) is connected to Q1-C and + to Q2-B.
    In my opinion the best cap would be 4.7uF.

    ReplyDelete
  12. I built 3 of these with MP35b transistors and they sounded terrible. I traced the schematic and as Tom Shand pointed out earlier the 5.1K isn't connected properly, it should go one row lower to the collector of Q3.
    Also tried reversing the polarity on the Fat capacitor, but to my ears it sounds a lot better as it is on the layout.

    This can be marked as verified once the correction is made

    ReplyDelete
    Replies
    1. Can You create oscillations once Fat capacitor is located as it is on the layout?

      Delete
  13. Replies
    1. It works for me... Built it more than a year ago. It's wild fersure lol. Haven't tried an original so I can't compare but from reviews it seems right.

      Delete
  14. hello..noob question..how to know which side + or - on capacitor..little confused..normally white is -..but on cap the white part smaller than black

    ReplyDelete
  15. Is 2n3906 a suitable sub for AC128?

    Is the value of 5.1k resistor critical?

    ReplyDelete
  16. Hey guys..try this out..put the second ac128 (q3) upside down..fattest fuzziness

    ReplyDelete