Some new Fuzz Factory questions

Started by mordechai, December 19, 2018, 05:12:46 PM

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mordechai

Before you rake me over the coals for not searching the forum for these answers...I did do several searches, didn't find the answers to some basic questions (even if they're buried in there...I am sure we all can forgive each other for periodically missing the needles int eh haystacks...) so I'm posting a few here.

1. Is there a way to make the sensitivity of the circuit a bit less, well, sensitive?  That is, I find usable tones in a very tiny range when I engage the gate and comp controls.  I'm wondering if there's a way to have a bit more control over those pots...maybe lowering the boost of the Q1 transistor would take it a bit...would reducing the 220K on the BC of Q1 accomplish that?  Possibly tweaking another resistor value (the 47K feedback resistor maybe?).

2. In the limited run "Hybrid" pedal -- the Z-Vex website identifies one of the transistors as a 2N404.  I'm guessing that would be Q3.  Anybody know what he's using for Q2?




thermionix

For the sensitivity issue, you could use smaller value pots in combination with fixed resistors.  It would take some experimenting to figure out which portion of the range you'd like to keep adjustable.  The fact that the pots are all linear taper makes that easier.  Like if you knew you only wanted "zero to noon" of a 10K pot, you could use a 5K pot and 5K (4.7K) resistor in series from lug 3.

I have no idea about the transistors.

abc1234

Quote from: thermionix on December 19, 2018, 05:25:27 PM
Like if you knew you only wanted "zero to noon" of a 10K pot, you could use a 5K pot and 5K (4.7K) resistor in series from lug 3.

I think OP could also use a SPST switch to add a 10k resistor in parallel with a 10k pot (which I assume is wired as a variable resistor) to lower it to 5k.

Personally my choice of either option would depend on the extent to which I want to preserve the original control.

i.e. My above suggestion would ensure the control is stock when the switch is open, and when it's closed you'd get a non-linear 5k pot; thermionix's would mean the pot would stay linear, but you'd lose the ability to go from 0 to 10k.

thermionix

It depends on whether the pot is wired as a variable resistor or voltage divider.  My answer was really for the voltage divider scenario, but looking at the schematic now, Comp and Gate are wired as variable resistors, so a smaller pot value might be all you need (depending on which portion of the control range you find useful).

mordechai

Of course...that makes perfect sense and is a far better solution that the other noodling I had in mind. Thanks VERY much!