Saturday, 14 October 2017

Nine Volt Nirvana Nitroburner Fuzz

Another from the man, the myth, the legend Joe Gagan. Not much to out there as far as info go, but it's another fuzz, based on the fuzzface with a bunch of tweaks. The only change I made is i removed the test switch, since I bought anyone wants to wire up a voltmeter in the pedal.

Here's Joe's notes on setting up the effect:


  • Set the bias pot to 0
  • Bias Q2 using the trimmer to -4.2V
  • When you change the bias pot it should max out at -7.4V
Note: I put it in the notes, but Q2 should be a high gain PNP Germanium transistor





9 comments:

  1. Dinosaur vid??
    is this pedal the same?

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    1. it's not, so...
      maybe it will show up here in yhe future,
      really liked the sound of it.

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  2. A couple of observations:
    First off, I don't see a connection to the base of Q2. There needs to be a jumper between it and the collector of Q1.
    Secondly, I'm not convinced that Q3 does anything at all. My first guess when looking at the schematic was that it was meant as an emitter follower to drive the voltmeter, except the voltmeter wasn't connected to it. Now it's just a transistor with an input and no output. I'm pretty sure you could remove Q3 and the 2.7k resistor that biases it, then use that lane to add the jumper between Q1 and Q2.

    Having said all that, I built a variation of this a few years ago w/o Q3 and it's a great sounding Fuzzface. I added the standard Fuzzface "Fuzz" control in series with the 22uF to ground.

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    Replies
    1. agreed, i'm not quite so sure the purpose of Q3 either. it is connected to the collector of Q2 so it may have an effect on Q2 whether or not the voltmeter is connected, since all the voltmeter just measures the amount of voltage between 2 points (this is how a voltmeter is in a car). nice catch on the missing link between Q1 & Q2. while i was moving things around I must have removed it by accident.

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  3. Schematic is here : http://2.bp.blogspot.com/-pYtRHhcjj-s/T3WA3lLr34I/AAAAAAAABO8/gm5lDM93Db8/s1600/Nitroburner.jpg

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  4. I built an NPN version by swapping the caps around and used 2n3904 and a GT404 Hfe ~100 and it sounds awesome. Thanks Zach!

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  5. How much gain is "high gain" here? I have a bunch of 2n1307's with hfe around 180, will they sound good here?

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    Replies
    1. no idea if they will sound good, but that should be enough gain. keep in mind typically different transistors have a slightly different tone, especially Ge. gavin built his with a Ge transistor with ~100hfe and it sounded good. remember that high and low hfe is different when talking about Ge vs Si, as Si typically have much higher gains.

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