More fuzz out of a Fuzz Face?

[DWBH]

So I built a silicon Fuzz Face. I've been experimenting with resistor values and transistors (in the 200-300 hfe range)
It sounds like a distortion, or a crunchy overdrive, and I'd like to obtain more fuzz.
Any tips?

[Joe Hart]

Add a third stage (like a Tonebender).  Also, you could add diodes to clip the signal more.
-Joe Hart

[DWBH]

The thing is.... I don't need more gain, and I think the Fuzz Face can provide the sound I want - Hendrix, early Gilmour fuzz tones.
I just want more edge to the sound - to make it sound more like Fuzz.

[jacobyjd]

adjustable clipping. Use a Ge diode pair and a pot.

[BAARON]

Do you have your gain turned up to 10?  Which schematic did you use?

[DWBH]

Later today I'll tell you what values I used.
Although I do remember I did not use a fuzz pot. Instead I used a 1k resistor.

[jacobyjd]

Also, what is the gain on your transistors?

Something else to check if it's not getting enough fuzz is the feedback resistor--you can lower that down to around 33k before you end up with problems. It's worth a try

[DWBH]

Lower? Won't that bring gain down, and consequently, lower fuzz?
I remember reading somewhere that increasing the feedback resistor increased gain.

[jacobyjd]

Hmm--maybe I have that wrong...I've built fuzzes with a 1M pot in series with a 33k resistor as a Gate control--crank that resistance way up and it will cause the fuzz to gate very predictably. Lowering it always seems to smooth out the fuzz for me--it's never really reduced the amount of breakup.

I'm guessing your problem has more to do with the transistors than anything though...I bet if you added an extra gain stage onto the front end of the circiut (i.e. put a booster in front of it), you'll notice a difference.

[Derringer]

Later today I'll tell you what values I used.
Although I do remember I did not use a fuzz pot. Instead I used a 1k resistor.

did you use a bypass cap across the 1k resistor?


more fuzz?

try something different ... run the output into another BJT gain stage that uses clippers ... either output to ground or between the collector and base ala the big muff or bassfuzz

watch your volume though

[DWBH]

Using the schem above:
- input cap is 10nF
- R4 is 100k with a 50k pot in series.
- gain pot was substituted by a 1k resistor, which is bypassed by a 10uF cap..
- R1 is a 22k pot
- R2 is 4,7k
- R3 is socketed and it's a 1,5k as of now.
- output cap is 68nF

Right now, Q1 is BC108A (hFE: 198) and Q2 is a BC172B (hFE: 290)

I've tried several transistor combinations, but no-one sounded like the one...

[earthtonesaudio]

http://www.geocities.com/tpe123/folkurban/fuzz/fuzzyfaces.html

...Scroll down to the bottom; check out the two on the left in particular.

[jrod]

Wouldn't a larger input cap and output cap yield better fuzz characteristics? 10nF and 68nF sounds kind of small! I like that 2.2uF cap at the input and .1uF at the output as shown in the provided schematic.

[edvard]

I've gotten good smooth fuzzy tones with silicons by increasing R4 to 330k or 470k (depending on the transistors) and upping the gain resistor to 2.2k.
Careful though, if those values are too out of line with the transistors you're using, you start getting buzzy/spitty noises and a weird compression effect.

I've also had good response with 10 nf caps on the input, once again depending on the transistors used. Try 50 nanos and see what happens.
Too large a cap on the input tends to muddy it up IMHO, but too small and your gain and stability go down.

[Derringer]

have you re-adjusted the bias on the collector of Q2 when altering the pots in the R1 and R4 positions?
that will make a difference

also, like Jrod said, a larger input cap will make a difference too

I wouldn't worry too much about the HFE's you have. You should be able to tweak something good out of those. Maybe not "the one" ... but something good.

[Solidhex]

Yo

  You might want to switch that 10uf out for a 22uf...

--Brad

[jacobyjd]

Yo

  You might want to switch that 10uf out for a 22uf...

--Brad

Or a 33--I've done that before if I don't have a 22 lying around.

[Dai H.]

The thing is.... I don't need more gain, and I think the Fuzz Face can provide the sound I want - Hendrix, early Gilmour fuzz tones.
I just want more edge to the sound - to make it sound more like Fuzz.

don't the "regular" FFace circuits sound pretty "Hendrix" already? (or at least to my ear they do)

[tcobretti]

What you may want to try is reducing the input and output caps. 

The input cap sorta controls how much signal gets in, so a smaller cap will lower the gain a bit but will also control the woofiness that FF can have.  As stated, you could increase the value of the feedback resistor to increase the gain back to where it was; I think the smaller cap/larger feed back resistor combo will get you decent gain with a clearer sound. 

The output cap acts like an EQ, so a smaller value will make the pedal thinner sounding and more abrasive, like many of the other fuzzes available at the time. 

All this depends hugely on your amp; some amps just hate FFs.

[DWBH]

The thing is.... I don't need more gain, and I think the Fuzz Face can provide the sound I want - Hendrix, early Gilmour fuzz tones.
I just want more edge to the sound - to make it sound more like Fuzz.

don't the "regular" FFace circuits sound pretty "Hendrix" already? (or at least to my ear they do)

Yes, they do. But mine doesn't. That's the problem.