DIY Fuzz Face ... Need help

[Gravity]

Hi,

 

I just perf-boarded a FF using this schem

 

http://www.harpamps.com/schematics/fuzzface.pdf

 

I also looked at this one at the top of the page ... pretty much identical

http://www.geofex.com/Article_Folders/fuzzface/fftech.htm

 

I had to use a 1uF cap on the input and a 5K pot in place of the suggested 1K

and I had to use 2N3906 transistors (fusking Radio Shack is practically useless ... ya feel me?)

 

When I run it with everything dimed I get a very mild fuzz.

 

Honestly, I don't really know what it's supposed to sound like but I assumed that the effect would be more dramatic

 

 

Would my substitutions cause any problems that you can think of?

 

Also, I have a 2.2uF non-polarized cap ... could that work for that input cap?

 

Thanks

[syscrusher]

I used 2N3906 for mine and the effect was over the top. I ended up customizing it for my own taste. 1uf on the input wouldn't hurt it at all and I used a 5k pot for mine also. A common mod is to use a 2k pot in place of the 1k.

 

Maybe check the 20uf cap is wired right on that 5k fuzz control. That cap gives it a lot of gain. Also check to make sure your transistors are wired correctly. I get the emitter and collector mixed up all the time.

 

I feel ya. Radio Shack used to be the bomb when I was a kid. You could build practically anything short of the nuclear bomb with Radio Shack bought parts. I think it's a lack of Science and Arts being stressed in today's school system. When I was a kid, Science and Arts were stressed and encouraged. Experimenting was all the fun.

[Gravity]

cool man, Thanks ... I'll take a look-see at what you suggested

 

knowing that i've got parts that should work makes trouble shooting much easier!

 

and yeah, it's the schools, but that's just a reflection of the "Lazy-American" attitude/way of life that permeates all things. Something doesn't work? Throw it away and buy another.

[Gravity]

the caps are oriented correctly

 

I was using a mono jack on the input, but I switched it to a stereo jack and nothing has really changed.

 

I triple checked the resistor values and pot values (made sure they worked right too), I replaced the transistors in-case I over bent the leads of the first pair or soldered too long on them

 

I still have the same sounds as before, with everything dimed, I'm actually just short of unity gain with slight distortion compared to the bypassed signal

 

the only thing that I can figure is that my ground scheme is messed up somewhere that I can't figure out

 

in this diagram

http://www.harpamps.com/schematics/fuzzface.pdf

 

the sleeves are grounded to earth ... I should just be treating that as a regular ground right? or at least, have continuity between the sleeves and all other grounded elements right?

 

I've grounded the following things to the back of the fuzz pot:

1. input jack sleeve

2. output jack sleeve

3. Q1 emitter

4. outside lug of the Volume pot

5. outside lug of the fuzz pot (with the positive lead of the 20uF cap)

 

 

frustrating... I can't figure it out!

 

 

edit ... just googled the 2n3906 and I got the opposite diagram from what was printed on the back of the transistor box that I bought ... I'm going to flip them and see what happens

[syscrusher]

 

the caps are oriented correctly I was using a mono jack on the input, but I switched it to a stereo jack and nothing has really changed. I triple checked the resistor values and pot values (made sure they worked right too), I replaced the transistors in-case I over bent the leads of the first pair or soldered too long on them I still have the same sounds as before, with everything dimed, I'm actually just short of unity gain with slight distortion compared to the bypassed signal the only thing that I can figure is that my ground scheme is messed up somewhere that I can't figure out in this diagram http://www.harpamps.com/schematics/fuzzface.pdf the sleeves are grounded to earth ... I should just be treating that as a regular ground right? or at least, have continuity between the sleeves and all other grounded elements right? I've grounded the following things to the back of the fuzz pot: 1. input jack sleeve 2. output jack sleeve 3. Q1 emitter 4. outside lug of the Volume pot 5. outside lug of the fuzz pot (with the positive lead of the 20uF cap) frustrating... I can't figure it out!

 

 

Sleeves are to earth ground and treat them as such. I know it's a stupid question, but do you have the battery wired right? The circuit uses a positive ground, so your battery should be wired so the positive is to ground and negative is the hot side. Short of that, I would look for shorts or bad solder connections.

[syscrusher]

Forgot, make sure the 20uf positive side is to ground.

[Gravity]

It was the transistors 100%

 

Damn RadioShack gremlins got me.

 

Printed on the backside of the package containing the 2N3906's was a diagram that had them oriented with the emitter where the collector should be! I {censored} you not.

 

I flipped them and now I have working FF!

 

here's a pic in all of it's Doc-Brown-Perf-Board glory along with my scratch built P1-EX and junction box bypass-box.

 

Seriously dude, thanks for your help. You got me looking at everything real close like and questioning all that I was taking for granted.

 

This is my first scratch built effect. I'm going to leave it perfboarded an hopefully learn and try some mods till I can make it unique enough to put into a housing and use regularly.

 

I guess I should probably get some germanium now to see what all the hype is about!

[syscrusher]

It was the transistors 100% Damn RadioShack gremlins got me. Printed on the backside of the package containing the 2N3906's was a diagram that had them oriented with the emitter where the collector should be! I {censored} you not. I flipped them and now I have working FF! here's a pic in all of it's Doc-Brown-Perf-Board glory along with my scratch built P1-EX and junction box bypass-box. Seriously dude, thanks for your help. You got me looking at everything real close like and questioning all that I was taking for granted. This is my first scratch built effect. I'm going to leave it perfboarded an hopefully learn and try some mods till I can make it unique enough to put into a housing and use regularly. I guess I should probably get some germanium now to see what all the hype is about!

 

Cool, glad you got it going. It's always the simple things. Getting that collector and emitter mixed up always gets me every time. It's the first thing I go to when it doesn't work. I always google the data sheets too and never trust what RS puts on the box.

 

Germanium sounds a bit smoother to my ears.

[m4rc1]

i followed up your discussion

i'm about to complete mine Fuzz

 

and a got a serious problem with the bypass, i followed up the diagram in the first post.

 

where it goes when the switch is OFF ?

 

i mean does the switch must be 2 side/double (6 legs)

it is not clear how the half switch is connected on each side

 

could you help me ?

 

i really excited to finish it and hear it at last

 

(sorry my bad english hope it was clear)

[Gravity]

Sounds like you have the correct switch.

 

Check out the picture here

http://www.muzique.com/lab/truebypass.htm

 

Post back if that doesn't help.

 

I actually did not bother to wire a switch to mine because I just wanted to see what it sounded like and I want to play around with it for a while to see what different sounds I can get.

[m4rc1]

actually i got only a 3 poles switch

 

but if I follow your advice the second position [off] is useless so it give me my answer :

the second position of the switch is empty

and the other got two wire

 

i try it out and maybe i'll hear it tonight

thanks

[Gravity]

A DPDT (double pole double throw) switch (6-pole) is ideal so that you can have a true bypass, but it looks like you could make it work with a SPST (single pole single throw) switch (3 pole) ... check out the schematic in this picture.

 

http://www.muzique.com/news/?p=66

[m4rc1]

hi,

 

i tested and it doesnt work at all

 

i tried to remove the switch and make the loop with wires but nothing happens.

i'll be forced to re-check all solders

 

but aftef i would really enjoy to make switch work cause a fuzz without his Wha ... its not the same (hendrix fanatic)

 

also i really appreciated your will to help me but the links you provide me appears to me 'forbiden' (server error) ... i even try the root site 'www.muzique.com' without any pages, is there any membership restriction ??

 

if you could show me what it was without this link i would appreciate it.

[Gravity]

 

[m4rc1]

finally i got a sound

 

but guess what :

it is the sound of a clear guitar no effet ... i guess if something burn it cut the circuit, only transistors have 3 leg so the circuit may run without being transformated

 

i'm confused

do you have any idea other than transistors ?

what other pieces may cause this ?

 

thanks again,

your site refered is again and again : Forbidden

i check with several browsers and in no case it works, thanks for the effort

[Gravity]

hey no problem ... always looking to lend a hand if I can

 

I would say that you just need to slowly go through the schematic and look at how everything is wired .... triple check all of your connections

 

make sure you have the right transistors

 

make sure your transistors are oriented correctly

 

 

 

I actually just transfered mine to a bread board and have been swapping caps to see what different sounds are in there to be had

 

fun stuff ... much cheaper and faster than building an amp!

[m4rc1]

simple curiosity

 

wich transistor did you used ?

 

I did the NPN version cause i got already those transistors and i planned maybe to wired it on a 9v adaptor in future.

 

I used 2n3904 (wich is recommended in the bottom of the pdf submited)

the 2n3906 is the exact Positive (PNP) of the 2n3904 (just in case you don't know)

 

so i made the mods as it says on the paper

and it seem not to works ...

on the next days i'll try to change piece by piece (all my wired are fifth time checked and connections on board too ...)

 

also i found a complete NPN version if you're interested in to plug in a wha with it (http://diy.musikding.de/berichte/eff/sifuzzface/bilder/fuzz-face-npn-schematic.gif)

 

hope you get better result than mine

thanks, bye

[F-Jag]

 

simple curiosity wich transistor did you used ? I did the NPN version cause i got already those transistors and i planned maybe to wired it on a 9v adaptor in future. I used 2n3904 (wich is recommended in the bottom of the pdf submited) the 2n3906 is the exact Positive (PNP) of the 2n3904 (just in case you don't know) so i made the mods as it says on the paper and it seem not to works ... on the next days i'll try to change piece by piece (all my wired are fifth time checked and connections on board too ...) also i found a complete NPN version if you're interested in to plug in a wha with it ( http://diy.musikding.de/berichte/eff/sifuzzface/bilder/fuzz-face-npn-schematic.gif ) hope you get better result than mine thanks, bye

 

 

Hey,

 

Here is a page showing how to use DPDT switch properly, and how to use NPN

transistors.

 

http://www.muzique.com/schem/fuzzface3.gif

 

Here is a classic Roger Mayer Fuzz with old AC128 PNP transistors.

 

http://www.harpamps.com/schematics_archive/EFFECTS/MISC%20in%20GIF%20FORMAT/rmclassicfuzz.gif

 

I have used AC151 transistors as well. You can use DPDT switch in the same way for true bypass. I suggest 2 kOhm pot instead of 1 k in alla variations.

 

F-Jag, Finland

[Gravity]

I used 2N3906's

 

thanks for the schem

[Gravity]

 

hmmm

 

 

what's the purpose of the 2M2 resistor off of the input? (suppress RF?)

 

What affect on tone/sound does 10K trimmer on the collector of Q2 have?

 

What does that diode (1N4001) going to ground from the positive battery terminal do?

[F-Jag]

hmmm what's the purpose of the 2M2 resistor off of the input? (suppress RF?) What affect on tone/sound does 10K trimmer on the collector of Q2 have? What does that diode (1N4001) going to ground from the positive battery terminal do?

 

2M2 resistor and diode (protecting?) are not needed, but you can use them if you want. Maybe somaone can explain their proper meaning. That trimmer is just for adjusting purposes, so you do not have to try different resistors, because every transistor has its own gain etc. I am not an engineer, and cannot explain. My own is a RM classic with AC151 germanium PNP-transistors, and works best with 4.5 volt battery.

[AMZ-FX]

The 2.2M resistor on the input is often called a pulldown resistor and its function is to drain off any dc voltage on the input capacitor, to prevent pops when the pedal is switched on.

 

The 1N4001 is a reversed-biased diode that is used to prevent damage if the battery is connected backwards.

 

regards, Jack

[m4rc1]

well

my post was to confirm if the NPN version seems ok

i know that several peoples have made the PNP version and worked ...

but with this circuit i got no sound and I fear is the ground wich is not collected right

 

can you confirm ?

[m4rc1]

I confirm

i finally got a sound

 

thank for those who helped

 

samples on request

[ibanezfoo]

 

I confirm i finally got a sound thank for those who helped samples on request

 

 

Lets hear it!