Thought I'd test the waters on the new change of policy.
Post your favorite Fuzz Factory mods.
I don't have any good mods. I have always wondered why it uses 5K volume pot? Seems low is this part of the mojo?
lifted from my post on the other thread:
...typical input cap blend mod adds a world of dimension to that pedal. the .01 cap between q1 and q2 gets a 100k pot>3.3 uf cap paralleling the .01. it's a beautiful thing.
my other favorite mod is to put a germ npn in place of the si q1. softens up the tone in a really pretty way.
other thoughts:
-if a high gain signal is fed into the FF ( zach has said all along the guitar should plug straight into the ff, i agree mostly, but have also gotten awesome sounds by placing other things in front of the ff), one may find that a 50k pot might be a nice replacement for the stab control. have not tried it specifically on a FF, but based on other experiments, the 5 k stab pot may not gate large signals as effectively as a 50k.
-i built a twinT wah that interfaced with a fuzzfactory. after much experimenting, i found the twin t to interact much better than an inductor type. will go find the schem and post here.
Make the input and output caps larger = bigger sound.
The way the circuit works (reversed PNP in a neg ground circuit)
and how the volume is tapped is why the 5K works.
It's a Fuzz Face as heart but with some clever trickery.
EDIT
Interesting about the twin t circuit in there Joe...
I'd like to see that.
John
john, i have seen guys over the years talk about putting in and out caps larger than the stock 10 uf. i don't think they need to be any bigger. the key to the whole 'bright' image that the fuzzfactory has had is the .01 going into q2. change that to larger, and you have a whole new animal.
re: the twin t - having to go back and study what i did. i was remembering wrong, the twin t was inserting ahead of the entire ff circuit. BUT i switched simultaneously with the 100k10uf cap sweep ( referred to above) that worked in tandem with the twin t on a dual gang.
OK, so I have a question... What should the HFE be for the AC128'S ? Banzai has them, but in many ranges.
i swapped in different 125 hfe ( using rg's method) germs for q3 with good results. never played around with q2.
I read somewhere Q2 = 90 hfe and Q3 = 120. I just used what I had and everything sounded OK. It might sound better with more carefully chosen transistors, I was working with what I had on hand.
I tried it out with Si transistors for Q2 and Q3 and sounded OK also. Though it didn't get that Ge sound. I think of more as a different sound rather than sound bad or wrong.
Quote from: joegagan on February 14, 2010, 11:32:55 PM
john, i have seen guys over the years talk about putting in and out caps larger than the stock 10 uf. i don't think they need to be any bigger. the key to the whole 'bright' image that the fuzzfactory has had is the .01 going into q2. change that to larger, and you have a whole new animal.
re: the twin t - having to go back and study what i did. i was remembering wrong, the twin t was inserting ahead of the entire ff circuit. BUT i switched simultaneously with the 100k10uf cap sweep ( referred to above) that worked in tandem with the twin t on a dual gang.
Joe
I see what you mean now. But .1uf not ".01".
That does make sense as the input cap blend
is a crucial element to a FF build (IMO).
Yeah, 10uf is plenty big in the input/output,
just bump that .1 up andit's
fat cityNever tried the in out cap thing on the Fuzz factory
I just remember people talking about the 10uf
caps being bumped...but that's not really an issue
now that I look at the schematic...
Don't listen to me :)
John
(http://img.photobucket.com/albums/v311/joegagan/DSCF3653.jpg?)
ok, let me see if i can explain this. there is a twin t wah
( basically the twin t circuit shown at geofex 'technology of the wah' article, with a few minor component tweaks that i can't remember)
that gets switched via a 3 pole 2 position rotary switch. this takes the circuit from non-wah'd fuzz fact to wah'd fuzzfact.
at the same time the wah is on, a large cap input cap sweep blend (within the ff circ) is also switched on.
the pot for the wah and the pot for the input cap blend are on the same wah shaft, being actuated together.
so, at the same time there is a wah input sweep going on, there is a cap sweep that keeps adding more low as the wah gets higher. it is very trippy
the harmonics are clashing and crashing, and the already crazy fuzz circuit does not know what to do.
every eighth inch of pedal travel is a new world.
(http://img.photobucket.com/albums/v311/joegagan/DSCF3648.jpg?)
if you check it out, the switched pot/secondary pot on the input cap blend is only active when the wah is in the off position.
i did not want to redraw or repost the entire ff schem, so i only showed the affected portion, Q1 and Q2.
(http://img.photobucket.com/albums/v311/joegagan/tom2.jpg?)
there is one other very useful mod to this particular pedal that i will post later, i have to trace what i did so i can accurately describe it. as a teaser, i will tell you that it is a pregain control that allows the fuzzfactory to go much more into the overdrive/ soft distortion territory.
thanks for the clarification, john. .1 it is.
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=22632&g2_serialNumber=2) (http://www.aronnelson.com/gallery/main.php/v/Processaurus/project-leavings/wilter.jpg.html)
I like the Stupidly Wonderful Tone control (http://hammer.ampage.org/files/SWTC.gif)on my clone. It originally had a BMP type Lo pass/Hi pass panning tone control but i couldn't get a usable sound out of my big amp playing live. In addition to the SWTC there are some switches on the side, one, on puretube's suggestion, brings in a cap strapped across the pot, to get treble bleed and make the tone control a odd sort of mid scoop. The other switch changes the output cap from stock (bassy) to a smaller one (70's midrange flavor) or to a tiny one hooked directly to the output (it lost too much volume in front of the SWTC) , for thin radio sounds. The latter is one of my favorite sounds. I'd show how to do it, but they aren't intuitive controls, though the sounds are good.
Also it has a photo cell in parallel with the stab pot, but it hasn't gotten a lot of use unfortunately. Some other dynamic control of it might be better.
The original is a really classic pedal design. Musicians I've lent mine to have really liked it, and recorded some creative sounds with it (especially multiple overdubs with different settings).
Soo now we can talk about "The Fuzz Factory"? ;D
Well i never had luck with any of Fuzz Face circuit out there, too much mojo in it i guess :icon_mrgreen:. i mean its soo simple circuit but i just cant make it work, its squeal, motor boating, noises and all of them ends up in my trash bin. So i never bother to try the famous ZVEX Fuzz Factory and since it was forbidden to talk about it here discouraged me even more.
But the itch still there and now the tide is turn ashore bringing new waves of policy and knowledge, i better grab my perfboard and surf in the sea of fuzz!
So help me guys... do you have any link to FF schematic and layout? ;D ;D :icon_biggrin:
Cheers!
Quote from: boogietube on February 14, 2010, 11:38:24 PM
OK, so I have a question... What should the HFE be for the AC128'S ? Banzai has them, but in many ranges.
I have a set of ZVEX Ge trannies here I can measure them if you want?!?!?!?!
Quote from: dukie on February 15, 2010, 02:49:01 AM
Soo now we can talk about "The Fuzz Factory"? ;D
So help me guys... do you have any link to FF schematic and layout? ;D ;D :icon_biggrin:
+1 for that, would be nice to build a clone. Thanks mr Vex
Joe
That looks really cool. The dual Twin t/cap blend sound like it takes it to another world.
You're the master of the dual pot :D
Here the schematic for the Fuzz Factory as redrawn by Gaussmarkov.
This one is a lot easier to understand than the others I have.
(http://basicaudio.net/Fuzz%20factory%20schem.PNG)
I'm working on a BMP style tone control, to be attached to the output of the pedal.
68k
|--- \/\/\/\-------|
| | \
| 6n8 = / 50k lin
| | \ <--------- Out
| /// /
------| \
| 6n8 |
|---||----|--------|
|
\
/
\ 47k
/
|
///
It's designed to not take away too much signal, but a bypass control can be implemented by connecting a spst switch to either end of the tone control. I might be adding a mid scoop switch too.
Also, I would suggest adding a filter cap of 10u to 100u between power and ground. My breadboarded version sound horrible without one.
Quote from: bumblebee on February 15, 2010, 03:53:12 AM
Quote from: boogietube on February 14, 2010, 11:38:24 PM
OK, so I have a question... What should the HFE be for the AC128'S ? Banzai has them, but in many ranges.
I have a set of ZVEX Ge trannies here I can measure them if you want?!?!?!?!
I'd love to have the numbers. Thanks, man!
Ok I'll check the hFE today sometime.
Quote from: CynicalMan on February 15, 2010, 10:25:37 AM
I'm working on a BMP style tone control, to be attached to the output of the pedal.
It's designed to not take away too much signal, but a bypass control can be implemented by connecting a spst switch to either end of the tone control. I might be adding a mid scoop switch too.
Also, I would suggest adding a filter cap of 10u to 100u between power and ground. My breadboarded version sound horrible without one.
OK, here's the scoop switch:
10n
|---||----|
o |
Scoop \ ///
o
|
68k |
|--- \/\/\/\---------|
| | \
| 6n8 = / 50k lin
| | \ <--------- Out
| /// /
------| \
| 6n8 |
|---||----|----------|
|
\
/
\ 47k
/
|
///
Awesome! I'll have to build one of these now (with some mods). I wonder how big of an enclosure I'll need to house all the knobs and switches...?
-Joe Hart
Ok, Q1 is MPSA18(IIRC), and the hFE for the Ge trannies is: Q2 is 80-Q3 is 100.
These are actual zvex stamped germanium transistors pulled from a handpainted fuzz factory. (I had a nicer set I liked so i swapped them)
Hope it helps nail the sound for you easier!
Quote from: Joe Hart on February 15, 2010, 04:16:53 PM
Awesome! I'll have to build one of these now (with some mods). I wonder how big of an enclosure I'll need to house all the knobs and switches...?
-Joe Hart
You can fit 8 knobs (+ battery, switch, DC, input, output) in a 1590B. :icon_twisted:
www.diystompboxes.com/smfforum/index.php?topic=81026.0
www.diystompboxes.com/smfforum/index.php?topic=81026.msg670857#msg670857
I made mine with a built-in with a battery eliminator..
(http://www.hbci.com/~erix/FX/fuzz_farm_outside.jpg)
I used a PIO .12uF between Q1 & Q2. Q1 is a 2N1973 (an old silicon NPN) w/ 158 hfe, Q2 is 2SA77 @ 60 hfe, Q3 is 2SB516 @ 103 hfe
(http://www.hbci.com/~erix/FX/fuzz_farm_inside.jpg)
Never played with a real one but this guy does some crazy stuff with the stab, especially with the gain all the way up.
ok,
erix
gain mod - lets the user find friendly overdrive-y sounds and other softer flavors. i was lucky, i had omeg pots in 220k. never tried the more common 250k, should work.
(http://img.photobucket.com/albums/v311/joegagan/Fuzzfactorygaincontrlmod.jpg?)
erix, that is a really pretty build. kudos!
Quote from: joegagan on February 15, 2010, 09:48:34 PM
gain mod - lets the user find friendly overdrive-y sounds and other softer flavors. i was lucky, i had omeg pots in 220k. never tried the more common 250k, should work.
(http://img.photobucket.com/albums/v311/joegagan/Fuzzfactorygaincontrlmod.jpg?)
Hi joegagan,regarding the mod,have you done it?Don't mind if you can upload for some sample?Very interesting :icon_lol:
hi, yes it is the 7th knob on the fuzzfact in the wah casing on page 1.
the pedal is currently out of order. will fix and make a sample.
Quote from: joegagan on February 16, 2010, 09:29:31 AM
hi, yes it is the 7th knob on the fuzzfact in the wah casing on page 1.
the pedal is currently out of order. will fix and make a sample.
Thanks. ;D Hope to hear from you soon. ;)
reposting the images from p[previous page, sorry i moved them
(http://img.photobucket.com/albums/v311/joegagan/schems/Fuzzfactorygaincontrlmod.jpg?t=1305319441)
(http://img.photobucket.com/albums/v311/joegagan/schems/tom2.jpg?t=1305319577)
well i've previously modded Fuzz Factories and the best result was the fuzz factory with additional switch that'd give you a bit glitchy from time to time octave down! then i finally ended up with another mod and named it The Factory. tho didn't include that octave down mod.... I'd share how i did it but i yet have to go back myself and re do it and see if it really works :)
I think I could use some clarification regarding the 10K Linear pot between the 470Ohm resistor and Q2. What exactly is it doing, and what effect would it have in a "normal" fuzz face circuit?
It would require somebody more clever than me to figure out the switching because I've been out of the loop for a while but the "swell" section from the Prescription Electronics Experience pedal works with the Fuzz Factory.
I've wanted to build a Fuzz Factory with a swell section for a while but could never figure out how to add the switch.
The problem is this. It will only swell at certain settings. Mainly, the volume of the Fuzz Factory has to be pretty much dimed. That means you'd have to turn the pedal all the way up when you want to use the swell section and remember to turn it back down when you don't because the pedal is freakishly loud. If there was a way to wire the Swell switch to bypass the volume pot replacing it with the maximum volume of the pedal diverting the signal into the Swell circuit (the Swell knob would be the new volume) it would be an awesome addition.
Here's what it sounds like
Quote from: vendettav on May 14, 2011, 02:16:45 AM... then i finally ended up with another mod and named it The Factory...
An unintended tribute to Lowell George, perhaps?
Quote from: Ben N on June 01, 2011, 05:18:17 AM
Quote from: vendettav on May 14, 2011, 02:16:45 AM... then i finally ended up with another mod and named it The Factory...
An unintended tribute to Lowell George, perhaps?
well idk really who Lowell George is. (may be a flame shield?) :P
The Factory is actually my 3rd album's name i just released. (lol was that sentence correct?? :P )
Let me try again, since I think my earlier question got lost in the shuffle -- what is the 10KL "gate" control actually doing to the signal between the 470Ohm resistor and the Volume pot? Since this circuit has the Fuzz Face at it's heart, would the 10KL between the 470Ohm resistor and the Q2 collector have a similar effect?
yes it would. keep in mind that in this schem, what we usually think of as 9v is ground. also, the way all the controls interact in the FF is a part of why the gate knob does what it does. also , the boosted signal from Q1 also plays heavily into this.
Quote from: joegagan on June 01, 2011, 02:25:32 PM
the boosted signal from Q1 also plays heavily into this.
So in a standard FF then, the gate function would have a different "sound" because the signal lacks the additional gain stage at the outset of the circuit?
Looking back at the schematic, given the flip in polarity that you noted, I wonder if the "comp" pot serves a purpose similar to the additional resistor on the emitter-to-ground of Q2 on the YAFF. Does it "open" or "close" the gain of that transistor?
Here's one of the 3 FF's I've built. A friend of mine gave me an old morely volume pedal so I gutted it and built the circuit into it, with the "Stability" pot being controlled by the foot pedal. It's pretty badass to control the self oscillating pitch in real time, and when you duck it all the way back it gets really nasty and bit-crushed. I dig it.
The funny thing is that I don't know why or where things are different than the original FF, but the knobs do not respond at all like the Zvex model. I just turn them until i get something useable. It's a little more fun that way I think. :) I'll try to post a video of it some time soon.
Here's some pics:
(http://i16.photobucket.com/albums/b27/ugly_guitar_guy/FuzzPedalTop.jpg)
(http://i16.photobucket.com/albums/b27/ugly_guitar_guy/FuzzGuts.jpg)
Hi everybody,
I have built 2 nearly identical FF over the past months and one of them has a much fatter sound and goes into heavy territories much easier. The other sounds thin and also needs the STAB knob to be turned lower than it should for oscillations to start creeping in. I switched between the two's Ge and 2N3904 and it didn't change anything. Q2 is about 60 and Q3 is 100. Both have very low leakage.
1. I thought of bumping the 100nF up a bit as suggested...how high should I go?
2. CAN anyone verify the GaussMarkov schematic or SABROTONE's layout or anything when it comes to pot lugs? It seems like every schematic is different when it comes to the pot configuration and I had mine corrected a million times until I believed I got it right (comparing to the original ZVEX video demo). It seems the SABROTONE layout is good but I am never sure about it.
Thanks,
D
funny this thread popped back up. im in the middle of building my first one but waiting on the 128's from mammoth (they're backordered, sucks), though someone from the Czech Rep is selling "a fuzz factory pair" of 128's and a 3904 "as a bonus" for 15$ shipped. below is my version of the layout and circuit. only thing i changed is added an additional electro in parallel at the input and output to bring back some low end that is connected to a DPDT toggle switch. otherwise it's stock. it's not verified YET, but hopefully soon. feel free to give it a go.
(http://kodiakklub.com/pedalpics/fuzzfactory-ETCH2.png)
(http://kodiakklub.com/pedalpics/fuzzfactory-layout.png)
(http://kodiakklub.com/pedalpics/fuzzfactory-schem.png)
I just built my first Fuzz Factory. To try and improve the bass response, I put extra switches to give the option of adding 47 uF caps in parallel to the input and output caps. I did this based on what I'd read in forums, without really thinking about things properly for myself first. This is what I found...
The output cap change from 10 uF up to (10uF + 47 uF) made absolutely no audible difference to the sound.
A bit of theory explains why. The RC high-pass filter in the output stage has a 3dB cutoff frequency of 1/(2 * pi * R * C) Hz. Putting R = 220k and C = 10 uF, gives 0.07 Hz. That's already way below any audible frequency, so boosting the output cap is a pointless exercise.
Boosting the input cap from 10 uF up to (10uF + 47 uF) was a different story. That didn't boost anything, but pretty much killed the signal completely.. The FF has a low input impedance by default. Boosting the input cap lowers the input impedance even further.
In the end I noticeably improved the bass response using a different cap mod...
Instead of putting a cap in parallel with the input cap, I left the input cap alone and added a lower value cap (0.47 uF) across the base of Q1 and ground (with the cap's negative terminal to ground).
You can think of this cap as leaking high frequencies to ground more than the lows.
The end result is a much warmer fatter sound. If the sound is too warm or muddy for your taste, then try a lower value than 0.47 uF (e.g. 0.1 uF).
OMG i did the same thing. (amazing pedal by the way, i see why he made a name for himself with this one). i boosted the input and output caps like you did, no really audible difference at all. guess i will have a make another....WAHOOO! :) thanks for the explanation doc. you are a way smarter man than I.
Actually, after playing a little more I've decided that the 0.47 uF cap made everything too muddy for me. Playing the high notes on the top E string were just too quiet. So I've just taken out that 0.47 uF cap, and followed the advice further up this thread ... i.e. boosting the 0.1 uF capacitor between Q1 and Q2 instead.
I have a switch that puts a 2.2 uF capacitor in parallel with it. If you do this mod, make sure the negative side of this cap is on Q1's collector, and the positive side is on Q2's base. I have seen advice before saying the exact opposite thing!! If you are not sure, measure the voltage between those points of the circuit. On my build, I found Q2's base at higher voltage than Q1's collector, so that's where the positive side of the cap went.
The result is a really FAT sound. One side effect is that the self oscillations happen at lower frequency (so you get lots of clicks).
If you do this mod, either make the cap switchable, or put a variable resistor in series with it so you can fade the big cap in and out,as opposed to switching it on and off like me.
I might post some soundcloud samples later.
that 0.1uf cap is not polarized so it shouldnt matter which way round you put it in there, correct? i will try putting the switchable cap in that position instead. thanks again.
If you've used a non-electrolytic cap for the 0.1 uF (as I have on mine) then it doesn't matter which way you have put it in.
However the 2.2 uF cap that I put across it was electrolytic and has to be put in the right way.
You can ignore what I said about the guitar controls not changing the pitch. They do, it's just that the really low frequency oscillations are just a series of clicks, and it's hard to notice them speed up or slow down when they are far apart.
My samples of the effect of adding 2.2 uF across the 0.1 uF cap.
http://soundcloud.com/alex-lawrow/fuzz-factory-modification
sample is amazing. gonna redraw my FF now and etch a new version. maybe ill turn the old one into a 2 or 3 knob vanilla version!!
Fat Fuzz Factory??? ;D
i ordered a set of those germs from the guy in the czec republic ... 15 bucks , on ebay , .... i had been drinking a bit , and was feeling discouraged .
I'm glad the samples were useful. Just to confirm about the orientation of the extra cap.
I've done a simulation of the Fuzz Factory hooked up to my guitar using the Circuit Lab website.
What a great site. You can even model the self oscillation, and the effect of the guitar controls on it's frequency!!
Anyway, a DC analysis shows that Q2's base will always be at least a few volts higher than Q1's collector (for all STAB values).
So the positive side of the extra cap definitely goes to Q2. I didn't just fluke things on my build :)
Here's a screen shot. The voltages shown on the left are for STAB set at maximum stability.
(http://img843.imageshack.us/img843/4731/fuzzfactorydc.png)
I worked on this simple looking, but complicated pedal.
The transistors hfe are very important.
I tried with silicon simple PNP, and the feedback where in almost every knob settings.
Tried with germaniums 2SB54, around 100/120 hfe, and they tamed a bit.
I need to find out how to bias correctly to use silicon ones.
Is that possible?
Hi, in most projects, fuzzies with germanium require negative power and positive ground
Here, the land is negative, and the food is positive, although PNP transistors
Usually this is achieved by requiring a voltage converter MAX1044 ICL7660s, etc.
Can you explain why this circuit works from ordinary polarity
How does the pedal feed (standard connector with a minus in the center)?
Just modded Q1 in a Fat Fuzz Factory with a 2N1308 I had laying around from a hoof build. Works as described. Also made an "industrial fuzz" from guitarPCB using 2N404 transistors in Q2 and Q3 with an OC140 in Q1. Both sound basically the same (when the FFF is set to normal FF C2 setting)
I do like this mod very much because it sounds like a harder edged fuzz face. Something to be aware of when a Germ NPN is subbed in at Q1, the oscillation sensitivity changes and the knob positions that create the oscillation change. It still oscillates - just differently and in a more limited range.
Also the pedal got less noisey.
For some people - this might be the one mod that makes the fuzz factory circuit more applicable in their rigs.
As always - YMMV