Silicon Fuzz Face Debugging

[Quadrapus]

Ok, so i redid the whole board. The right way this time. And I have the same problem.

[Quadrapus]

Here are the new voltages:

Voltage at the circuit board end of the red battery lead = 8
Voltage at the circuit board end of the black battery lead = 0

R2
8
0

R3
0.4
2

R4
8
8

C1
+=0.4
-=0

C2
+=0
-=0

C3
2
8

C6
+=8
-=0


Q1
C =0
B =0.4
E =0

Q2
C=8
B=0
E=0.6

D3
+=0
-=8

VR1 (from top)
8
8
7.8

[Quadrapus]

I've now connected all the components directly, and checked that the resistance between the connections is 0. It still had the same issue. I'm leaving it down to component failure.

[smallbearelec]

Something is still not wired right. Q1 Collector and Emitter are both at ground--that definitely won't fly. Q1 Collector and Q2 Base should be at the same voltage, and it should be more like 1.5 volts.

I know that this is frustrating. You might want to back up and consider getting to know the circuit on a solderless breadboard before you tackle a soldered build. Here's a How-To that I did that has been used successfully by numerous beginners:

https://www.smallbearelec.com/HowTos/BreadboardSiFF/BreadboardSiFF.htm

This is essentially the same circuit, and you can set it up with the components you have. Here is the intro article that explains how the breadboard works and is used:

https://www.smallbearelec.com/HowTos/Breadboarding/BreadboardIntro.htm

The advantage of using a breadboard is that you get to see and correct mistakes quickly. Then, once the circuit works, you can commit to solder knowing that the components are good. The same store where you are buying parts should have one.

[Quadrapus]

Thanks for the advice, i'll pick up a breadboard tomorrow and try it out.

[dwmorrin]

Checking out your new set of voltages...
-R3 at 2V and Q2 emitter at 0.6V doesn't work since they're supposed to be connected directly together.  Recheck that node.
-R2 is going from power to ground.  Check that R2 isn't shorted to ground/0V.
-Volume pot 3 should have 0V.  Possibly you checked this while it was still discharging.

[Quadrapus]

Something is still not wired right. Q1 Collector and Emitter are both at ground--that definitely won't fly. Q1 Collector and Q2 Base should be at the same voltage, and it should be more like 1.5 volts.

I know that this is frustrating. You might want to back up and consider getting to know the circuit on a solderless breadboard before you tackle a soldered build. Here's a How-To that I did that has been used successfully by numerous beginners:

https://www.smallbearelec.com/HowTos/BreadboardSiFF/BreadboardSiFF.htm

This is essentially the same circuit, and you can set it up with the components you have. Here is the intro article that explains how the breadboard works and is used:

https://www.smallbearelec.com/HowTos/Breadboarding/BreadboardIntro.htm

The advantage of using a breadboard is that you get to see and correct mistakes quickly. Then, once the circuit works, you can commit to solder knowing that the components are good. The same store where you are buying parts should have one.

Completed the circuit on a breadboard, and still the same problem!


Here's a picture:
Edit: Broken link.

[smallbearelec]

Completed the circuit on a breadboard, and still the same problem! Here's a picture:

The pic is not accessible from here. Pls try posting again.

[Quadrapus]

Can you access these?

Edit:Broken

[smallbearelec]

Can you access these?

They don't show directly on the Forum, and I get a 403 error when I paste the links. Maybe try Photobucket?

[Quadrapus]

ok, here:

[deadastronaut]

@quad:

have you got a  bigger photo?..


edit: also check continuity on your breadboards + and - rails..

some boards are split half way..and need to have a jumper connecting them.

[Quadrapus]

Yep, there is continuity.

[Quadrapus]

Hmm, now I think it might be my audio pot. I have a linear pot instead of a log pot.

[smallbearelec]

Hmm, now I think it might be my audio pot. I have a linear pot instead of a log pot.

Changing the taper of the pot won't help. It looks like the emitter of Q1 is connected to the positive supply bus. It should go to ground.

[Quadrapus]

Hmm, now I think it might be my audio pot. I have a linear pot instead of a log pot.

Changing the taper of the pot won't help. It looks like the emitter of Q1 is connected to the positive supply bus. It should go to ground.

Hmm, i fixed that up, still the same. I'll measure some voltages.

[Quadrapus]

@quad:

have you got a  bigger photo?..


edit: also check continuity on your breadboards + and - rails..

some boards are split half way..and need to have a jumper connecting them.

You were right. the board was split. It's working now!

[Quadrapus]

There is still a bit of buzzing when not playing, don't know if it's just interference, other than that it's working great. Thanks everyone for all your help!

[smallbearelec]

There is still a bit of buzzing when not playing, don't know if it's just interference, other than that it's working great.

This is a completely unshielded build. It will quiet down when you do a soldered build and mount in a metal case.

Thanks everyone for all your help!

You're welcome, and CONGRATULATIONS! You have learned, painfully, the first rule of building circuits from a vetted schem: When it does not work, the cause is usually either mis-wiring, poor soldering or both. Take voltage measurements at Q1 and Q2 C, B and E before you solder again. Let us know how it goes with making it work on Vero. After you get that far, you'll probably have Qs about to add a stomp switch and in-use LED.

[Quadrapus]

There is still a bit of buzzing when not playing, don't know if it's just interference, other than that it's working great.

This is a completely unshielded build. It will quiet down when you do a soldered build and mount in a metal case.

Thanks everyone for all your help!

You're welcome, and CONGRATULATIONS! You have learned, painfully, the first rule of building circuits from a vetted schem: When it does not work, the cause is usually either mis-wiring, poor soldering or both. Take voltage measurements at Q1 and Q2 C, B and E before you solder again. Let us know how it goes with making it work on Vero. After you get that far, you'll probably have Qs about to add a stomp switch and in-use LED.

I was a bit too eager, and I went ahead before reading your post. But it worked! Now I'm just waiting for the paint on my enclosure to dry. Thanks again for all your help and advice! I'll let you know how the off-board wiring goes.