NEED HELP Breadboarding a Silicon Fuzz Face Pedal

[bonzoboi]

Hi everyone!

I am a first-time pedal builder and user of this forum!
I have been attempting to build the Fuzz Face pedal using silicon transistors for the past month or so, and have had little to no success in my attempts.
Initially, I followed the schematic and wiring diagram on General Guitar Gadgets, but after having issues completing the project, I came to this website for help and found a link to the page http://diy.smallbearelec.com/HowTos/BreadboardSiFF/BreadboardSiFF.htm where I found very helpful and fleshed out instructions on how to breadboard a Silicon Fuzz Face pedal.
However, after multiple attempts, I have not even been able to pass a signal through my breadboarded circuit.
I consulted the "what to do when it doesn't work page" and went through the checklist to troubleshoot my circuit, and will list the values below:



1. What does it do, not do, and sound like?
Does not pass a signal.
2. Name of the circuit =
Silicon Fuzz Face
3. Source of the circuit (URL of schematic or project) =
http://diy.smallbearelec.com/HowTos/BreadboardSiFF/BreadboardSiFF.htm
4. Any modifications to the circuit? Y or N
No.
5. Any parts substitutions? If yes, list them.
I replaced the transistors recommended (2N2222A or BC108) with 2N3904 silicon transistors, which were suggested as alternatives by the author of the page. Also, I'm using a 1K OHM Linear Taper Potentiometer rather than the 1K Reverse Audio Potentiometer recommended. Also, I'm using a 0.01 mF ceramic capacitor, rather than one made of polyester film.
6. Positive ground to negative ground conversion?
No.
7.Turn your meter on, set it to the 10V or 20V scale. Remove the battery from the battery clip. Probe the battery terminals with the meter leads before putting it in the clip. What is the out of circuit battery voltage? => 9.62 V

Now insert the battery into the clip. If your effect is wired so that a plug must be in the input or output jack to turn the battery power on, insert one end of a cord into that jack. Connect the negative/black meter lead to signal ground by clipping the negative/black lead to the outer sleeve of the input or output jack, whichever does not have a plug in it. With the negative lead on signal ground, measure the following:
Voltage at the circuit board end of the red battery lead = 9.6 V
Voltage at the circuit board end of the black battery lead = -9.1 V

330 R = 9.58 V
33K R = 9.58 V
8.2K R = 9.36 V
100K R = 0.64 V

0.01 mF C = 9.36 V
2.2 mF C = 2.78 V
22 mF C = 0.64 V

Q1 T
C = 3.38 V
B = 2.78 V
E = 0 V

Q2 T
C = 3.98 V
B = 3.38 V
E =  0.64 V

500K P
CCW = 0 V
W = 0 V
CW = 0 V

1K P
CCW = 0 V
W = 0.64 V
CW = 0.64 V

Here's a link to a picture of my breadboarded circuit: http://www.aronnelson.com/gallery/main.php/v/Schematics-etc/20170126_150217.jpg.html

Let me know if you see anything that is wrong, or have any suggestions of things to try!

Thanks,
John

[GGBB]

There are a lot of wires that disappear off the picture, so that makes it difficult to know if something "off-board" is the problem. One thing I do notice (I think) - the jack that is shown in the picture appears to have the tip connected to ground (left-most red wire). If that's true, nothing else matters at this point.

[bonzoboi]

My apologies, here is a link to a picture that includes all of the off-board components: http://www.aronnelson.com/gallery/main.php/v/Schematics-etc/20170126_150217.jpg.html

The diagram that the site I've been using for this breadboard showed the tip of the input jack going to ground, so is that incorrect? I switched the tip to power and it made more noise, but didn't pass the signal correctly, and there also seemed to be a grounding issue (like when I touched the output jack with my hand there would be noise, but not a correct signal from the guitar).

[GGBB]

The diagram that the site I've been using for this breadboard showed the tip of the input jack going to ground, so is that incorrect? I switched the tip to power and it made more noise, but didn't pass the signal correctly, and there also seemed to be a grounding issue (like when I touched the output jack with my hand there would be noise, but not a correct signal from the guitar).

Could you be mixing up tip and sleeve? Input jack tip goes to circuit input. Output jack tip to circuit output. (But in a finished pedal those connections would be through the bypass switch.) Both jacks' sleeves go to ground. Without getting into complicated electronic theory, which I only understand minimally, tip is where signal lives. Sleeve/ground is where signal dies (power would also provide death to signal). Think of ground like a black hole - anything touching it disappears forever.

[bonzoboi]

I made sure to have the input tip going to the circuit input, and the output tip going to the circuit output, and both sleeves going to the ground. I'm still getting the result of no signal being passed through, and I can only get it to make noise when I put my hand on either the output jack or the 500K potentiometer, which only results in buzzing and no guitar signal (so it seems like there is still a grounding issue?).

Thank you for your help and recommendations!!

[GGBB]

You should go over the circuit routing again. Step by step from input through output, and from power to ground. I already see - in the last pic you posted - that the circuit input goes to the input cap, and from there to the fuzz pot via the blue jumper wire that runs from position H1 to G7. It should go to the transistor base on row 5 not 7. The jumper beside it doesn;t look right either. The breadboard pics at the smallbear site are small - zoom in to see them better. It is common to make these kinds of mistakes when you are starting out building, so don't get discouraged or embarrassed. Just take your time, be very detailed in your work, and double triple check everything.

[feddozz]

Here's my 2 euro cents.

First of all, do not give up. You will get there. Your breadboarding skills are good, there might be an error. That does not mean the rest is rubbish. This hobby is all or nothing and if you read through the pages of this forum you'll see it happens to the most experienced too.

This is the best hobby ever. If you keep trying you'll be rewarded for you effort, immensely. Just keep thinking at the first time you will get sound through that thing. It will be huge!

Now let's get practical. For a good troubleshooting you need to stop believing in things. Stop believing that your guitar works. That your amp works. That your cables work. Start prooving that they work. Once that's done we'll move to your components and breadboard. Proof that your pots work and transistors (do you have a multimeter with HFE measurement?). After that you need to audio probe the hell out of your circuit.


It is your first breadboard project, it might even be that you do not push your components hard enough to make contact. It's difficult fits is to say from a picture, although they seem well inserted. I say this just to give you an idea on the type of things that could stop your signal.

You might want to consider breadboarding an LPB1 first. It is simpler, it uses less components and a single transistor. That could allow to test one transistor at a time and avoid using pots if you wanted. Just a suggestion.

In any case of the another of the points above that is not clear especially on the proofing, just say it and we'll get it sorted out.

Enjoy your troubleshooting.

f

[bonzoboi]

Thanks so much for these positive replies!!
I really appreciate the encouragement, and am super excited to make this happen and continue with my interest in pedal construction!
Unfortunately, I won't be able to get back to troubleshooting until tomorrow afternoon, but I will try some more things out and get back to y'all!

[Ben Lyman]

I can't see the picture very well but I'll just share my most repeated mistake when boarding a fuzz face. I get all the components in and connected properly but then.. I forget to put that one single plain old wire from Q1c to Q2b 

[bonzoboi]

Hello again!

So today I replaced the input mono jack with a stereo jack and only wired the tip and sleeve like the smallbear website instructed; and I trimmed the legs on my resistors and rewired the entire breadboard to make sure everything was securely inserted, following the exact placements of the smallbear website's. But, I'm still having the same issues as before, which is that this does not pass a signal at all, and when I touch my hand to the output jack I get a buzzing white noise. My battery is good, so I'm going to go through and do some more component testing, but I took some more pictures that give a more clear look at my breadboard:

Over-view: http://www.aronnelson.com/gallery/main.php/v/Schematics-etc/20170127_140911.jpg.html
Closer over-view: http://www.aronnelson.com/gallery/main.php/v/Schematics-etc/20170127_140957.jpg.html
Side-view: http://www.aronnelson.com/gallery/main.php/v/Schematics-etc/20170127_141021.jpg.html

I'll post my component results soon in another comment, but I just wanted to provide these updated pictures to see if there are any glaring issues.

Thanks!

[thermionix]

I can't see the picture very well but I'll just share my most repeated mistake when boarding a fuzz face. I get all the components in and connected properly but then.. I forget to put that one single plain old wire from Q1c to Q2b 

For me it was Q1e to ground.  Same problem, no component so you just forget!

[bonzoboi]

@BenLyman, I have Q1c going to Q2b.
@thermonix, I have Q1e going to ground.

Here's an updated list of my component testing and project overview (the left/right/bottom/top legs of the resistors are meant to reference their positioning in the overview image I posted previously today):

1. What does it do, not do, and sound like?
Does not pass a signal.
2. Name of the circuit =
Silicon Fuzz Face
3. Source of the circuit (URL of schematic or project) =
http://diy.smallbearelec.com/HowTos/BreadboardSiFF/BreadboardSiFF.htm
4. Any modifications to the circuit? Y or N
No.
5. Any parts substitutions? If yes, list them.
I replaced the transistors recommended (2N2222A or BC108) with 2N3904 silicon transistors, which were suggested as alternatives by the author of the page. Also, I'm using a 1K OHM Linear Taper Potentiometer rather than the 1K Reverse Audio Potentiometer recommended. Also, I'm using a 0.01 mF ceramic capacitor, rather than one made of polyester film.
6. Positive ground to negative ground conversion?
No.
7.Turn your meter on, set it to the 10V or 20V scale. Remove the battery from the battery clip. Probe the battery terminals with the meter leads before putting it in the clip. What is the out of circuit battery voltage? => 9.08 V

Now insert the battery into the clip. If your effect is wired so that a plug must be in the input or output jack to turn the battery power on, insert one end of a cord into that jack. Connect the negative/black meter lead to signal ground by clipping the negative/black lead to the outer sleeve of the input or output jack, whichever does not have a plug in it. With the negative lead on signal ground, measure the following:
Voltage at the circuit board end of the red battery lead = 9.10 V
Voltage at the circuit board end of the black battery lead = 0.00 V

33K R
BottomLeg = 9.10 V
TopLeg = 3.26 V

100K R
LeftLeg = 2.66 V
RightLeg = 0.60 V

8.2K R
LeftLeg = 3.87 V
RightLeg = 8.90 V

330 R
BottomLeg = 9.10 V
TopLeg = 8.90 V

0.01 mF C
LeftLeg = 8.90 V
Right Leg = 0.00 V

2.2 mF C = 2.78 V
PositiveLeg = 2.66 V
NegativeLeg = 1.20 V (it starts at 1.20 V, and then continues to decrease in voltage as I continue to hold the multimeter lead to it, is this an issue?)

22 mF C = 0.64 V
PositiveLeg = 0.60 V
NegativeLeg = 0.00 V

Q1 T
C = 3.26 V
B = 2.66 V
E = 0.00 V

Q2 T
C = 3.87 V
B = 3.26 V
E =  0.60 V

500K P
CCW = 0.00 V
W = 0.00 V
CW = 0.00 V

1K P
CCW = 0.00 V
W = 0.60 V
CW = 0.60 V

[Hemmel]

> Voltage at the circuit board end of the red battery lead = 9.08 V
> Voltage at the circuit board end of the black battery lead = -8.58 V

Unless I'm misunderstanding, shouldn't the black battery lead read 0V ??

[thermionix]

With the negative lead on signal ground, measure the following:
Voltage at the circuit board end of the red battery lead = 9.08 V
Voltage at the circuit board end of the black battery lead = -8.58 V

Do you not have the neg battery lead going to signal ground?

[Edit: Yeah what Marc said]

[bonzoboi]

Yeah, you're both right.
I just measured it wrong.
It does read 0.00 V at the circuit board end of the black battery lead.
I'll modify the post to update the results.

[Hemmel]

Yeah, you're both right.
I just measured it wrong.
It does read 0.00 V at the circuit board end of the black battery lead.
I'll modify the post to update the results.

Don't worry about that. You're troubleshooting and we're helping.
I doubt that measurement mistake was the origin of your problem, though.
Let's keep looking.

[bonzoboi]

Since I'm getting O V reading on all parts of my 500k pot, do you think that that might be the main part of the problem?
Like could it be a component leading up to that's keeping it from getting any voltage?

I'm really loving and appreciating all the support from this community, thanks everyone!

[thermionix]

0 VDC is correct for the volume pot.  It is isolated from DC by the .01 output cap.  That's why it's there, also called a "blocking" cap.  If not for that cap, there would be DC coming out the output jack and screwing up the bias of whatever was next in your signal chain.  And your volume pot would be scratchy.

From the voltages you post, your Q1 base and collector seem the most off.  Should be more like 1.4v on the collector and .6v on the base.  Do you have the 100k from Q2e to Q1b?  Are you sure you have the transistors oriented correctly?

[thermionix]

Okay I've spent more time looking at your pictures.  I see you have the 100k installed and the orientation correct for EBC transistors.  I can't see anything wrong, seems like it should make a sound.  If I were you, I would pull each resistor and check value with a meter.  If all correct, I would sub caps.  If you're really getting no sound whatsoever, maybe that .01 is open.

[GGBB]

NegativeLeg = 1.20 V (it starts at 1.20 V, and then continues to decrease in voltage as I continue to hold the multimeter lead to it, is this an issue?)

No. Realistically (not part of the actual circuit but common practice) you would have a ~1M pull down resistor from the negative leg of the input cap to ground, which would pull this to 0V.

The breadboard looks good - nicely done. As feddozz stated earlier - don't assume anything works - prove it. So now, prove the breadboard works by using your meter to verify connectivity between all component pins. If it has an audible conductivity setting use that to make things go faster. Start by checking from the tip of the input jack to the negative lead of the 2u2 input cap. Then check from the positive lead of the input cap to the base of Q1 and the 100k resistor. And so on. While doing that, also check that each pin is NOT connected to ground (unless of course it is supposed to be). Breadboards are not the most reliable beasts.