My univox super fuzz pedal kit won't work

Started by snow123, March 09, 2021, 04:57:33 PM

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andy-h-h

Quote from: snow123 on May 01, 2021, 06:58:00 PM
somehow the 1st lug on the expand knob is grounded to the enclousure

It's supposed to be - have a look at the schematic

andy-h-h

#161
Quote from: snow123 on May 01, 2021, 07:19:48 PM
wtf everything on the input jacks sleeve is grounded to the enclosure

The sleeve is ground, so that's OK, in fact it should work like this.  You need to be worried about the tip.   

http://generalguitargadgets.com/pdf/ggg_superfuzz_lo.pdf

Go through your build with the black probe held firmly on the enclosure, and use the red probe to test everything that should not be connected to ground (black on the diagram).

Then check that everything that should be grounded, is grounded.

Test the switch in the on and off position.


snow123

the tip on both jacks are grounded to the enclosure

snow123

and the pots are grounded where they should be

andy-h-h

#164
Quote from: snow123 on May 01, 2021, 07:35:25 PM
the tip on both jacks are grounded to the enclosure

That's quite a problem, but it should have an easy fix.

First make sure that the tip connector is not actually in contact with the enclosure.  From some of the photos you posted, the tip lug looks really close to the enclosure. 

There's also some connections that look uncomfortably close on the board, any movement and they could short.



I can't see what's going on with the wiring or switch, however I would check the switch, as it looks a bit interesting.  I would go as far as to say that you will most likely find issues with the switch wiring.   

Test continuity between the points that should not be connected, bearing in mind that this will change depending on the on/off status.

image from stew mac





snow123

Here's some better pics of the footswitch, and the resistor the goes before the led is covered in electrical tape. And I checked continuity on the b2 and 0 pads and there doesn't seem to be a short or anything there.






eh la bas ma

Quote from: snow123 on April 30, 2021, 09:27:18 PM

i meant my DMM beeps when i put one lead on the leg and the other lead on the joint

I am not sure if it's helpful, but "grounded" usually means "connected to ground", I think there will be some confusion if you use that word to express the idea of connection between two points.

" ground or earth is the reference point in an electrical circuit from which voltages are measured, a common return path for electric current", " ground is the lowest potential in a circuit, for exemple the minus side of a battery or DC supply. "
"One Cannot derogate, by particular conventions, from the Laws which relate to public Order and good Morals." Article 6 of the Civil Code.
"We must not confuse what we are and what society has made of us." Theodor W. Adorno.

snow123

Quote from: eh la bas ma on May 01, 2021, 10:08:55 PM
Quote from: snow123 on April 30, 2021, 09:27:18 PM

i meant my DMM beeps when i put one lead on the leg and the other lead on the joint

I am not sure if it's helpful, but "grounded" usually means "connected to ground", I think there will be some confusion if you use that word to express the idea of connection between two points.

" ground or earth is the reference point in an electrical circuit from which voltages are measured, a common return path for electric current", " ground is the lowest potential in a circuit, for exemple the minus side of a battery or DC supply. "

oh, sry for the confusion.

bluebunny

^^ yeah, this.

When you've been saying "grounded", you really mean "connected".

No wonder my head hurts!  :o   (Never mind the lack of coffee so far...)
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Ohm's Law - much like Coles Law, but with less cabbage...

snow123

#169
but why is the tip on the output jack grounded?

antonis

Quote from: snow123 on May 02, 2021, 03:29:27 PM
but why is the tip on the output jack grounded?

Very nice question and thank you very much for asking us..!!  :icon_cool:
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

snow123

Quote from: antonis on May 02, 2021, 03:44:58 PM
Quote from: snow123 on May 02, 2021, 03:29:27 PM
but why is the tip on the output jack grounded?

Very nice question and thank you very much for asking us..!!  :icon_cool:
y tho

snow123

and i just checked the schematic and everything that should be grounded, is grounded.

snow123

wait so im assuming everything on the commons area of the footswitch should be grounded, so that would be including the tip of both the input/output jacks?

antonis

No..

IN & OUT jack SLEEVES should be grounded,,
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

antonis

OK.. just take a look below about grounding points,,

"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

snow123

ik the sleeves should be grounded, im asking about the tip.

aelling

Quote from: snow123 on May 02, 2021, 04:18:07 PM
ik the sleeves should be grounded, im asking about the tip.
That's what we are trying to help you with, they shouldn't be grounded but they are being shorted by something. Like we been asking above are you making sure the tips are not touching the enclosure walls? If the tips touch the walls it shorts signal to ground.



andy-h-h

Quote from: snow123 on May 02, 2021, 03:55:44 PM
wait so im assuming everything on the commons area of the footswitch should be grounded, so that would be including the tip of both the input/output jacks?

The middle pins on a switch are only called common, because they are always connected to either the pin above or below.

If the tip of the jack is grounded, the signal will go to ground, meaning no output.   Some switching systems ground the circuit input when it's switched off to reduce noise and other issues, they never ground jack tips.

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Are you 100% sure that both of your jacks are functioning as they should be?  It is possible to twist them and mess with connections (I've done this once before).  As mentioned, there's still a possibility that they are touching the enclosure.

I think you are going around in circles at this stage.  I would suggest;

1) desoldering the jacks and stomp switch, test the jacks and switches

2) make sure the circuit actually works, which I don't believe you have done yet

3) redo your off board wiring, and make sure it passes signal when bypassed

4) put it all back together now that you know you have a working circuit, and switching system





andy-h-h

#179
oops - accidental post    :icon_lol: