Help With Fuzz Face Circuit

[Elixrx66]

I'm not necessarily a newbie but at the same time I don't seem to display much aptitude for building circuits but nevertheless I tried building an NPN Fuzz Face circuit on a breadboard and I have gone over the thing again and again and yet it still won't work. I used the correct value components. I can't figure it out and it's driving me crazy. Could anyone who is knowledgeable take a look at this and tell me where I went wrong? I would really appreciate it.[/img]


Btw asking as a brand new member. Do you always have to jump through such hoops every time you post something on this forum. I can see when you are signing up but to make you answer questions every time you post seems a little ridiculous.

[Chillums]

Hi there and welcome.  I just took a quick look but check out the two areas I circled.  The top circle looks likes it needs to be moved to the right one as it's not connected to anything the way it sits now.  The resistor circled doesn't look to be connected either.  It's easy to put parts/wires in the wrong column/row with these breadboards.... I do it all the time.   

[GibsonGM]

I believe the 'hoops' you have to jump thru will time out after enough posts...I don't know how many it takes, tho.  Welcome

[duck_arse]

you've ruined my binary postcount, but welcome anyway. I'll need 100,000 - 1 more posts before I go binary again.



I add my arrows to Chillums excellent circles. what's going on there, there is nothing connecting that bottom row - OR - you have not provided enough information. for a start, post the circuit diagram of the circuit you are building - this is every time, every circuit. post the layout diagram of the circuit you are building if there is one. and more photo, please, we can't see whatall those wires are, or if atall. tell us everything. pots, jacks, switches.

then describe what doesn't work, how doesn't it work, what does it do/not do. and voltages. measure the voltages and post them here, for the supply and all the transistor pins. please. post whatever, we'll help with what we want and need.

the more often you post, the quicker the hoop jumping ends.

[Elixrx66]

Okay so I have the jumper wire from the first pot going to ground. I also added a trimpot in place of the 33k resistor but then I read you still need the resistor. I can get rid of it if it won't make any difference. So basically I have the wiper of the second pit going to ground and the CW going to the 10nf cap.

[Elixrx66]

Here it is in final form. I actually ended up replacing the 8.2k resistor coming off the collector of Q2 so I could adjust the voltage to 4.5v. I know everything is a little tight and may be hard to see every thing. The electrical tape is just there to hold the leads to the pots in place because they are always slipping out. I haven't tried plugging it in yet to see if it works.

[Phend]

If duck tape isn't available I use electrical tape on everything.
Good luck, actually won't need it since that circuit is a great build.
Easy.

[matopotato]

A DMM with continuity beeper could be really useful. Follow the schematic and verify on your board that each component is connected to the next one(s). This should hopefully show you any places where you might have "mis-wired" on the breadboard.

[Elixrx66]

I got rid of the trimpot and put the 8.2k resistor back in place. Why make things more difficult? I went through it and even triple checked to make sure everything was where it was supposed to be and it still didn't work. Deductive reasoning told me that it must be a faulty component. I tested each one and they all test fine. One of the transistors doesn't have an hFE reading but it doesn't read open. I really don't know wtf could be. No matter how much I wish and no matter how hard I try I just don't have any aptitude for this kind of thing.

At least I didn't have to answer 6 questions before I could respond so that's a plus.

[ElectricDruid]

I went through it and even triple checked to make sure everything was where it was supposed to be and it still didn't work. Deductive reasoning told me that it must be a faulty component.

That's a faulty deduction! Let's look at it like this: You haven't proved that the connections are good, only that that you haven't been able to find anything wrong.

In my experience, that just means you've been staring at it for too long, and you start to see what you *think* is there rather than what actually is. This is why going for a long walk helps, or leaving it for a couple of days and then coming back to it. You literally can't see what's right in front of your eyes. It's just a weakness of human perception. We see what we want to see. *Please* don't ask me how many times I've been stung by this or how many hours I've wasted!

I tested each one and they all test fine. One of the transistors doesn't have an hFE reading but it doesn't read open. I really don't know wtf could be. No matter how much I wish and no matter how hard I try I just don't have any aptitude for this kind of thing.

No-one comes in being able to do this straight away, so don't get disheartened. Debugging is pretty much always a pain in the a$$, even when you've been ding it for years, but it's definitely a part of the job of getting stuff going, and you *do* get better at it (like any skill) so don't give up just yet! With a bit of help from the people around here, you'll get it running.

There's a lot we still can't see from your picture. It looks like the red wire coming in on the left in the input, but you don't tell us that. The transistors are visible, but I can't see where the legs go exactly or how they're orientated. There's a load of red wires going off the top to pots (presumably) but I can't see those, so I don't know if they're wired correctly. There's two other blue wires and a red wire going off to the right and the bottom that we don't know what they do.  We can help, but we need a complete picture!

[matopotato]

Yes, like Tom points to it is very easy to lose track when breadboarding.
So if my continuity testing fails to show what I have missed, I just take out the wires and components and start over.
I recently had to do this twice for a more complex build. As frustrating as that might be I think you sort of learn the circuit a bit better in the process.
If you have a multimeter with no beep, you can measure zero resistance between components instead.

Few are born as expert pedal  builders, it is a learning experience and you have to stick with it. It will reward you piece by piece and there are many pedals waiting to be built by you I am sure.

[Phend]

Please post a photo showing board, pots and jacks.
Are the sleeves of both jacks grounded?

[brett]

"One of the transistors doesn't have an hFE".
That's a fail.  Replace it with a transistor of hFE greater than 50.
If you're measuring hFE, maybe you can measure the voltages on each leg of each transistor?
That'll give us a LOT of help.
Stick with it.  You're probably one connection or one device from a great circuit.

[m7b52000]

I have had more success breadboarding when I have used pre-existing layouts  for turret/ tag board e.g this one from tagboardeffects