Silicon Fuzz Face Debugging

[deadastronaut]

yay!..glad you got it working!.. 

stick little wire jumpers across your boards + and - in the middle gap for future use..


: the silicon fuzz is fine as is , but personally i prefer a pre gain control, just has a better control of the 'gain/fuzz ' imo..

you may find the fuzz control is either on or off (not much ''useable adjustment'' with the 1k fuzz control ...but hey you can always breadboard up another one right!.

have fun.

[zombiwoof]

Small Bear sells a 1K reverse-audio pot to cure that problem with the fuzz control.  It spreads out the taper near the end of the wiper rotation, to give better control.
Al

yay!..glad you got it working!.. 

stick little wire jumpers across your boards + and - in the middle gap for future use..


: the silicon fuzz is fine as is , but personally i prefer a pre gain control, just has a better control of the 'gain/fuzz ' imo..

you may find the fuzz control is either on or off (not much ''useable adjustment'' with the 1k fuzz control ...but hey you can always breadboard up another one right!.

have fun.

[Quadrapus]

Urgh, now it stopped working again. The output is clean, I think it's the fuzz pot. The resistance was at around 1600 before and not moving when I turned it, and now it reads over 2000. Strange, I guess I'll buy a reverse log pot.

[Quadrapus]

Here's the completed pedal:



Thanks again everyone for all your help!

[deadastronaut]

cool, looks like you did a great job on that. 

[Quadrapus]

For some reason my led is on in bypass mode and off when fuzz is on. I used tonepad's wiring diagram 5. Anyone know what this could be?

[dwmorrin]

Miswired footswitch.  Check the LED connections vs. the audio connects on the switch.
I didn't look up your wiring diagram, but it should just be a matter of understanding how that switch works.
Figure out how the switch is lighting up the LED, and swap the two terminals around.

[Monotremata]

you may find the fuzz control is either on or off (not much ''useable adjustment'' with the 1k fuzz control ...but hey you can always breadboard up another one right!.

Is this pretty much how they all work?? I dug out  my GGG Fuzzface today (I just did the standard NPN silicon one) and decided to give it a run.
Figuring JD knows what hes doing, I put the 2369A's back into it that came with the kit (I threw in some 2904's from Rat Shack when I built it and I have no clue why), got the voltage set to 4.5, yada yada..

But Ive noticed the fuzz control just doesnt do much at all. Its extremely subtle, adding some 'warmth' to my AC15, and the fuzz doesnt really kick in until its just about all the way up, and then it goes right into like super purple haze mode.
Didnt change anything out other then the trannies, but last time I played this thing I couldve sworn it had a smoother range on it with the 2904s.. But then again I built this thing in 2008 and it very very rarely gets any use other then screwing around at home once in awhile (Im a Boss HM-2 guy as far as dirt goes) so it could be me.

Never really dug this through my JCM800, but its actually pretty rad with my AC15. With the volume on my Tele all the way up, its a pretty woofy fuzz, but if I back it down just a hair (you can hear the point where it 'lays back') it keeps the raspy fuzz but actually cuts out some of the bass so I can do palm mutes with it and they dont flub the notes together into a big bee swarm.. Minus the obvious EQ section, its actually getting pretty close to where my HM-2 gets me. Crank up the amps master and here comes the singing sustain that it lacks..

[zombiwoof]

you may find the fuzz control is either on or off (not much ''useable adjustment'' with the 1k fuzz control ...but hey you can always breadboard up another one right!.

Is this pretty much how they all work?? I dug out  my GGG Fuzzface today (I just did the standard NPN silicon one) and decided to give it a run.
Figuring JD knows what hes doing, I put the 2369A's back into it that came with the kit (I threw in some 2904's from Rat Shack when I built it and I have no clue why), got the voltage set to 4.5, yada yada..

But Ive noticed the fuzz control just doesnt do much at all. Its extremely subtle, adding some 'warmth' to my AC15, and the fuzz doesnt really kick in until its just about all the way up, and then it goes right into like super purple haze mode.
Didnt change anything out other then the trannies, but last time I played this thing I couldve sworn it had a smoother range on it with the 2904s.. But then again I built this thing in 2008 and it very very rarely gets any use other then screwing around at home once in awhile (Im a Boss HM-2 guy as far as dirt goes) so it could be me.

Never really dug this through my JCM800, but its actually pretty rad with my AC15. With the volume on my Tele all the way up, its a pretty woofy fuzz, but if I back it down just a hair (you can hear the point where it 'lays back') it keeps the raspy fuzz but actually cuts out some of the bass so I can do palm mutes with it and they dont flub the notes together into a big bee swarm.. Minus the obvious EQ section, its actually getting pretty close to where my HM-2 gets me. Crank up the amps master and here comes the singing sustain that it lacks..

That problem with the fuzz pot not doing much until the last part of the rotation can be cured by getting the reverse audio taper pot from Small Bear.  It spreads out the range of good fuzz sounds in the last half of the tone pot rotation, giving you more control with the pot turned up.  You can do the same thing by just reversing the connections on the stock regular audio tone pot, but it will work backwards if you do that (max fuzz will be with the pot turned fully counter clockwise).  You could just first try reversing the connections, and use it working backwards to see if it fixes the problem, then if the backwards pot action bugs you, you can replace it with the reverse audio pot.  This is assuming that the fuzz pot you have is an audio pot, and not linear (reversing the connections on a linear pot will make no difference).

Al

[Monotremata]

This is assuming that the fuzz pot you have is an audio pot, and not linear (reversing the connections on a linear pot will make no difference).

Al

And theres the catch! Just looked at the parts layout again, which was dated 2007 so Im assuming my 2008 kit is the same, and yup. Comes with a 1k linear for the fuzz. And go figure the only spare pot I have lying around is audio, but its a 100k I pulled out of a dead 80s DOD flanger..

In theory (and since Im jobless and seriously penny pinching at the moment) could I throw a 200ohm resistor across the 1k linear pot and trick it into becoming a 1k reverse audio pot??
Just read the article at Geofex explaining this but man Im bad with math, and terminology hehe. I figured out 200 from using that graph at the very bottom and went with curve 5 (its a 1k pot so if Rt=R/b, then 200=1000/5 right??).
I couldnt figure out though whether or not that was going to raise or drop the resistance of the pot though...
I can follow layouts and breadboard schemes all day long and my soldering's awesome but man the science behind it still confuses me!
I remember when I dropped Trigonometry in high school, the teacher told me it was the smartest thing I did all semester haha!

[dwmorrin]

Just read the article at Geofex explaining this but man Im bad with math, and terminology hehe. I figured out 200 from using that graph at the very bottom and went with curve 5 (its a 1k pot so if Rt=R/b, then 200=1000/5 right??).
I couldnt figure out though whether or not that was going to raise or drop the resistance of the pot though...

Adding resistor in parallel drops the resistance.

Originally, thought you were wrong about the 200Ω, but I think you got that right...

[zombiwoof]

This is assuming that the fuzz pot you have is an audio pot, and not linear (reversing the connections on a linear pot will make no difference).

Al

And theres the catch! Just looked at the parts layout again, which was dated 2007 so Im assuming my 2008 kit is the same, and yup. Comes with a 1k linear for the fuzz. And go figure the only spare pot I have lying around is audio, but its a 100k I pulled out of a dead 80s DOD flanger..

In theory (and since Im jobless and seriously penny pinching at the moment) could I throw a 200ohm resistor across the 1k linear pot and trick it into becoming a 1k reverse audio pot??
Just read the article at Geofex explaining this but man Im bad with math, and terminology hehe. I figured out 200 from using that graph at the very bottom and went with curve 5 (its a 1k pot so if Rt=R/b, then 200=1000/5 right??).
I couldnt figure out though whether or not that was going to raise or drop the resistance of the pot though...
I can follow layouts and breadboard schemes all day long and my soldering's awesome but man the science behind it still confuses me!
I remember when I dropped Trigonometry in high school, the teacher told me it was the smartest thing I did all semester haha!

I haven't read the GEO article in a long time, does it cover tapering resistors?.  Putting a resistor across the outside (1 and 3) lugs just changes the resistance of the pot (lowers), but to mimic the reverse audio taper I think you have to put a resistor from the middle lug (wiper) to lug 1, and another resistor from wiper to lug 3.  Is that what you were reading about?.  If it's not in the GEO article, I know there's a description and calculator somewhere for making a linear pot into an audio or reverse audio pot.   It might be in the FAQ on this site, I don't recall exactly where I saw it.  If someone else has more experience with tapering resistors maybe they'll chime in here.

Al

[Monotremata]

I haven't read the GEO article in a long time, does it cover tapering resistors?.  Putting a resistor across the outside (1 and 3) lugs just changes the resistance of the pot (lowers), but to mimic the reverse audio taper I think you have to put a resistor from the middle lug (wiper) to lug 1, and another resistor from wiper to lug 3.  Is that what you were reading about?.  If it's not in the GEO article, I know there's a description and calculator somewhere for making a linear pot into an audio or reverse audio pot.   It might be in the FAQ on this site, I don't recall exactly where I saw it.  If someone else has more experience with tapering resistors maybe they'll chime in here.

Al

Yeah I this is the article I read.. Most of it covers the tapering dealio..
http://www.geofex.com/Article_Folders/potsecrets/potscret.htm

I get how to do it, but I couldnt really tell through all the math and whatnot if by me adding a resistor from the wiper to the CW lug decreased the resistance of the pot or simply changed the taper. I have that 100k audio taper laying around but theres no mention of doing it with audio pots so I figured I would stick with modding the linear.
I came up with the 200 figure using the reverse log series resistor graph at the bottom. I just wish he would put some simple table at the end like "So basically if you have X value pot, use Y value resistor. If you have A value pot use B value resistor" but at least I learned a bit about resistors haha.

I tried these calculators initially when I was just going to try and tack like 3 resistors to the 100k audio pot to decrease it. Afterwards I found the Geofex article and went that route..
http://www.diystompboxes.com/analogalchemy/emh/emh.html
The Tapered Pot calculator is for faking an audio pot with a linear one, but you cant tell it you have a 1k pot and wanna keep it a 1k pot. The calculator tells me the value is too high. I can change the resistance but I dont wanna do that. I just wanna fake the taper.
The Linear Pot calculator tells you what to use to drop the resistance of a larger value pot, so I can plug in the 100k and to get it to 1 it says I just need two 50k resistors. But again, the calculator says Linear pots, I dont know if the same math would apply to an audio pot.

Ill probably just give in and go buy a pot, but would still be useful to know for future reference. One of these days Id like to be able to do more then just put together a kit hah.