Sunday, 20 January 2013

Jen Fuzz

It seems that not all of the sixties fuzzes were verbatim tonebenders. There's not that much difference blueprintwise, but still noticeable difference. Some might want to clone this too...

Geiri modded his build a bit to get its sound closer to his preferences. Some of you might want to try these mods out as well. Word from Geiri and demo of his modded build:
I basically changed the 10nf cap by the input to a 100nf. The 10nf that goes to level 3 changed to a 47nf and I changed the 1.2nf to a 10nf. Very simple and for me, it improved the pedal a lot. the 2k pot was too big before the change and it would start to make noises but after changing the caps, it's fine. I recommend using a 2k pot if you're gonna do these changes. - When you max the gain, it's still quite bright and more like a distortion but if you switch to neck pickups, it goes a lot fuzzier so I kinda like it!


  1. that "some" would include me i guess haha :D
    will most likely give it a go once im done with the ones on the waitlist, thinking of building that shoe distortion for my bassplayer and verify it tonight!

  2. Hmm. Forgot to tag this one as the note come over on different channels :) Fixed that now.

  3. miro is that really verified?i've build it with nothing changed except the 6.8k to an 8.2, and attact doesn't do nothing, and the effect i get is a very bad overdriven fuzz-like spiting sound...very bad..while trying to find what's wrong, i put green leds for diodes, and they didn't light (if that helps).give me a hand please!!!

  4. Replies
    1. Well. There is Geiri's video of his build, so i'm more than confident of this being verified.

      The 6K8 resistor you've replaced with 8K2 sets the bias for Q3 and your symptoms sound like you have the circuit simply misbiased. Attack not working suggest that you have a short or something else wrong around that pot or its connections.

    2. Post front and back pics and measure the DC voltages between all pins and ground and post them here and we can see what could be amiss. Unless we have this sort of information it's impossible to offer advise from just a description.

  5. i didn't though i could be that stupid not seeing the was late...i'll change the resistans with a 4.7+2.2 (no 6.8k) and see what's happening. if nothing again, i'll send you pics.thanks a lot! the "old" voltages are
    q1 c:9.34
    q2 c:3.6
    b:0.58 (too low...?)
    q3 c:8.15
    at the attack pot there is almost no volts
    also put 1nf for 1.2nf
    and for 150k i've used 220k//470k

  6. nothing...after the resistor change, i get nothing.the c voltage on q3 now is 9.12. all the others the same.

    here is the link of the pictures of my build.

    hope you find something.
    i've also checked the schematic and everything seems fine ...

  7. Anyone guys?have you made it to check the photos?
    ξεναγος νεκροπολης

  8. oh!i can't find the f£$%ing fault!...if anyone make it work please post some photos...i think i'll leave it alone to rest...thanks anyway...

  9. want to hear a joke?
    first my opinion on this pedal...
    i've just build it...
    it's very nice oldschool fuzz, and by oldschool i mean that you really feel the "old" thing by playing with the attack. but i guess i won't box it..not that is that bad, but cause i think blue box is much closer to what i like.
    the joke now (or my stupidity)..
    i've put a 22k for 22r...first mistake
    and secont as i said above that i'll put in series the 4,7+2.2.....well...i've soldered them in parallel!!!!
    so if you've build 10 pedals...your still a beginner...(not that i though something else...!)sorry for all questions before...should look more carefully

  10. Hi!
    I don't understand why I don't have any sound when turn it on ! Bypass ok.
    Anyone can check to pics ???
    As I did not have the right values ​​for capacitors, I assembled several for 15n and 1.2n.
    Diodes ?
    Thanks all

    1. A pic of the back of the board would help

      There are two columns that are useless. I made a hole inadvertently but this should not pose a problem to the rest of the circuit (last column, second last row) These are 2n5088 therefore connected as shown.
      16.8n instead of 15 (10n +6.8). For 1.2n is 1n n +0.1 +0.1 n
      There is no really no sound.

    3. The diodes are they in a good way? And the transistors?
      Is that may come from the two empty columns?
      Please, Help! thanks

  11. what transistors does geri recommend to use with these changes? still 5088?