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Saturday, 5 January 2013

Vorpal Fuzz

Let's have a super noisy and fuzzy saturday!

From effdub: I really like the Fuzz Factory pedal, but I never use the Gate or Stability knobs, so I thought it would be cool to slap together a circuit somewhere in the F.Factory neighborhood but with all the wacky noise-maker type sounds cut out. Also, I wanted this circuit to work with common, off-the-shelf transistors, instead of mojo/hype germanium parts.
I started off with something *like* a slimmed-down Fuzz Factory, but what I ended up with was quite a bit different in terms of fuzz structure and overall sound. Just to be totally clear, this circuit is not a clone of the Fuzz Factory.

Possible Mods
* You might want to go with higher values for the input and output caps, especially if you normally use single coil pickups. Instead of the stock 10uf, try 22uf, 33uf, or even 47uf for both the in and out caps. You could even go bigger for use with bass. My preference (thanks to my friend Baj2K over at the BYOC forums) is to use a 22uf for the input cap and a 47uf for the output cap.

 * There are dozens of transistors you could use in this circuit. Try out different gains in the Q1 (boost) section. Some transistors sound brighter/darker than others, so experiment like mad. Seriously, in the Q2/Q3 spots, I've tried everything from ultra-low gain 2N128's (hFE of about 30) to 2N5087s (hFE of about 400 or so). Having the Bias control top-side makes adjusting for different transistors quite trivial. Experiment!!!

 * My personal favorite tranny for Q2/Q3 is the 2N5139. The sound is less "siliconish" than the 2N4402, mainly owning to the difference in gain. These are available from Smallbear Electronics for less than $1 each. The gain on these is between about 80 and 120 hFE, so any transistor in this range should sound about the same.

 * Lowering the value of the 10K resistor off of Q2's collector will change the character of the fuzz. Try a 5.1K to start. Lower values will yield progressively sputtery, farty types of fuzz. This is a prime spot for a DPDT switch to swap values.


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13 comments:

  1. Doron Barness5 January 2013 at 17:35

    wow...looks like a very interesting build.
    I have built the FF and I do use STAB and GATE a lot. Nonetheless, this seems like a worthwhile adventure.

    Thanks,
    D

    ReplyDelete
  2. atomicwombat5 January 2013 at 19:56

    i just finished this one up, but i can't get it to work. something is amiss here. my build is good, no bridges or anything, but it just farts out. no real sound at all, and the controls don't seem to have much effect if any at all. i used a 2N3904 for Q1, and 2N4403's for Q2 and Q3. i had a look at the layout on the effdub site, and his pcb layout seems to have some differences . i don't know. any info or ideas? the sound clip of this sounds sweet. i'd love to get it working right. thanks

    ReplyDelete
    Replies
    1. mirosol6 January 2013 at 00:23

      My mistake. I'm so sorry.

      For some idiotic reason i didn't take into account that both fuzz and bias pots connect to Q1 collector and Q3 emitter. You can fix it by just placing a link between rows 2 and 5 on the right hand side.

      The schematic is here: http://www.forrestwhitesides.com/files/up/img/layouts/vorpal_schem.png
      +m

      Delete
    2. mirosol6 January 2013 at 00:46

      I posted the corrected layout... (upper 10ยต one row to the right and added the missing link)
      +m

      Delete
  3. lowbrow6 January 2013 at 00:30

    Is there a cut missing to the right of Q2 base? Also it looks like the emitter and collector of Q2 are swapped?

    ReplyDelete
  4. lowbrow6 January 2013 at 00:34

    I see, looking at the schematic, I am wrong about Q 2 being flipped. Sorry:)

    ReplyDelete
    Replies
    1. mirosol6 January 2013 at 00:44

      That did confuse me a bit too at first. But of course the emitter goes to +9V - if it is PNP.
      +m

      Delete
  5. atomicwombat6 January 2013 at 16:48

    you can tag this one. its verified. i soldered in the missing link, and it fired right up. i might end up playing around with the input and output cap values and some different transistors to see if i can get it to sound closer to my liking. it sounds good, although i'm not really blown away by it, but thats me. who knows, the next guy might love it. i keep building these little fuzz circuits looking for one that does blow me away. so far, no luck, but i am having a blast building them along the way!!

    ReplyDelete
  6. Jimijam7 January 2013 at 16:24

    I will have to make one of these since I am not a big fan of the FF nintendo modes, this one will be usable!

    Hey fuzz crazies... any chance on a Foxrox Hot Si Fuzz???

    ReplyDelete
  7. Unknown8 January 2013 at 13:16

    Can anyone help me convert this schematic http://www.generalguitargadgets.com/diagrams/ezface_blend_cap.jpg?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a to vero?
    It is a very good sounded fuzz.

    ReplyDelete
  8. Dave20 December 2013 at 22:34

    Just finished my build of this. Its quite a nice one and definitely has the fuzz factory tone, I'm not certain if its a keeper or not yet, we'll see.
    Cheers as usual for the great layouts.
    Dave

    ReplyDelete