Silicon Fuzz Face - How to get less "fuzz"??

Started by davidjnichols, February 14, 2013, 04:12:17 PM

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davidjnichols

Hey guys, I'm working on a Fuzz Face type pedal for a first build.  I've done a few mods to the schematic that I read about on the internet.  I changed the value of the 330 resistor to add more volume, reduced the value of the 2.2 input cap to cut a little bass, and ran a .047 cap in tandem with the 330 resistor (now increased to 860 or something) to apparently add more warmth or something.  Not sure about that mod.  Anyway, my question is:

How do I get less grit/fuzz/distortion?

When fuzz pot is turned all the way down, the pedal is really fuzzed out.  When fuzz pot is turned all the way up, its slightly more fuzzed out, but either way, there's a shitload of grit.  I can reduce the volume on my guitar a bit to tweak the fuzz level, but I'd rather have the pedal more responsive - maybe have less fuzz altogether.  What should I tweak in the schematic to get less fuzz? 

I'm currently using two 2N2222A silicon transistors.  Is the level of fuzz produced by these pedals just dependent on the type of transistor?  Would changing the value of the resistor that leads to Q2 change the amount of fuzz (the spot where there's a trimpot for germanium transistors)?  I'm building off the GGG silicon fuzz face schematic.  You can see it here:

http://www.generalguitargadgets.com/pdf/ggg_ff5_sc_npn.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

Any insight?  Sorry if I sound completely new; it's because I'm completely new!  This is my first build.  Thanks for the help!!

Seljer

Silicon transistors generally have more gain than germanium transistors, hence more fuzz.

A common mod for fuzzfaces which kind of accomplishes what you want is to wire a potentiometer in series with the input. Refer to the "boutique fuzz face" schematic on ggg :)

CodeMonk

There is one mod I did just for shits 'N grins once.
Take some diodes (1N914 works) and put 2 BtB between the collector and the base.
Turns it more into a dirty OD type thing though.

Maybe make it switchable or put a pot in there?

davidjnichols

Quote from: CodeMonk on February 14, 2013, 06:59:11 PM
There is one mod I did just for sh*ts 'N grins once.
Take some diodes (1N914 works) and put 2 BtB between the collector and the base.
Turns it more into a dirty OD type thing though.

Maybe make it switchable or put a pot in there?

On the schematic, would I put them at the junction of Q1 and Q2?  Where the base of Q2 meets the collector of Q1? 

CodeMonk

Quote from: davidjnichols on February 14, 2013, 07:14:21 PM
Quote from: CodeMonk on February 14, 2013, 06:59:11 PM
There is one mod I did just for sh*ts 'N grins once.
Take some diodes (1N914 works) and put 2 BtB between the collector and the base.
Turns it more into a dirty OD type thing though.

Maybe make it switchable or put a pot in there?

On the schematic, would I put them at the junction of Q1 and Q2?  Where the base of Q2 meets the collector of Q1?  

Oops...sorry about that.
Between the Collector and Base of Q1.

And yeah, I think putting a pot inline would allow you to adjust the level of "change"
As for pot value, I have no idea. Experiment.

chptunes

Those 2N2222 Transistors might be a few shades too hot.  Try some 2N2369's, as in Jack Orman's YAFF (yet another fuzz face).  The lower gain is supposed to be sweet.

-Corey

LucifersTrip

Quote from: davidjnichols on February 14, 2013, 04:12:17 PM
When fuzz pot is turned all the way down, the pedal is really fuzzed out.

I would first double-check your wiring since it  shouldn't be really fuzzed out when turned all the way down

always think outside the box

smallbearelec

Chptunes and LucifersTrip are both correct. More poop on biasing and transistor selection can be found here:

https://www.smallbearelec.com/HowTos/BreadboardSiFF/BreadboardSiFF.htm

Regards
SD

Gus

This schematic sounds good with 2n2222s.  It will bias up with a number of Si transistors.  Change the input and output caps to taste the 10uf is for more of the 2.2uf input sound. Some of my earlier posted circuit have parts values you could find at Radio Shack years ago
http://www.diystompboxes.com/pedals/gusFuzzFace.gif

Note the use of the 10K and 100ohm resistors at the first stage and the placement of the bias control.  This is different than 33K 100ohm and grounded emitter circuits


R.G.

You could also search this forum for transistor piggy backing to get effectively lower gains.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

mattumbi

I've added a 100 ohm emitter resister on Q1 to builds, gleaned from Gus' fuzz face mod schematics

GGBB

Quote from: LucifersTrip on February 14, 2013, 10:04:16 PM
Quote from: davidjnichols on February 14, 2013, 04:12:17 PM
When fuzz pot is turned all the way down, the pedal is really fuzzed out.

I would first double-check your wiring since it  shouldn't be really fuzzed out when turned all the way down



Ditto.  I have a high-gain silicon BC108C fuzz with hfe in the 500 area and when the fuzz pot is turned down there isn't much fuzz at all.  Something could be wrong with your pot or wiring.
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davidjnichols

Quote from: GGBB on February 15, 2013, 10:34:54 AM
Quote from: LucifersTrip on February 14, 2013, 10:04:16 PM
Quote from: davidjnichols on February 14, 2013, 04:12:17 PM
When fuzz pot is turned all the way down, the pedal is really fuzzed out.

I would first double-check your wiring since it  shouldn't be really fuzzed out when turned all the way down



Ditto.  I have a high-gain silicon BC108C fuzz with hfe in the 500 area and when the fuzz pot is turned down there isn't much fuzz at all.  Something could be wrong with your pot or wiring.

I replaced my pot and rechecked all my wiring a few times and everything seems to be good on that end.

ode2no1

with the fuzz pot below about 3 o'clock on a fuzz face you generally get a warm, clunky, not super inspiring guitar tone. with it turned all the way down you should be getting very very little fuzz. something has to be wired wrong. even with the highest gain transistors possible you shouldn't be getting very much fuzz with the pot turned down.

pinkjimiphoton

yah,
all of mine are pretty brutal when cranked, but turned down, they should turn OFF.
bet there's a solder bridge you missed.
;)
once ya get it sorted out, you may wanna double the value of the attack pot. may give you more "useable" range.
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LucifersTrip

#15
also, using a 500 hfe transistor instead of a 200-300 gainer is not really going to give you more fuzz. when you use really high gain transistors, it just gets more compressed and synthy.
always think outside the box

pinkjimiphoton

TRUE, but they don't clean up as well with the guitar volume pot.
depends on what kind of fuzz you want... synthy, heavy, sweet, versatile,dank disgusting BROKEN... and all points in between! ;)
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"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr

Thecomedian

low frequencies seem to get 'Synthy' more easily. first three strings on bass? nice. last two strings. BVVVVVVVRRRR.  :icon_lol:
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