My univox super fuzz pedal kit won't work

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

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snow123


snow123

ok, im just gonna put heat shrinks and electrical tape everywhere to make sure there arent any shorts anywhere

snow123

and the center ground on the footswitch is defo a massive culprit for shorts

snow123

#143
ok so now the true bypass isnt working, it only lets the dry signal through when the pedal is on

andy-h-h

Quote from: aelling on April 30, 2021, 10:21:22 PM
One of the legs of R1 is in the wrong solder pad, I've marked in purple which leg it is and which hole it needs to go in ( :icon_mrgreen:).

Fix this and report back.





Suggestions:

PROBE IT
Build an audio probe and use it to trace the signal (google it).  If you were using a probe, you would have found out that that the signal was not actually making it to the first transistor (R1 being on the wrong pad), and you would have worked this out quickly.

SIMPLE IS GOOD
Unwire the circuit from the stomp switch - just have the straight inputs and outputs and no other distractions.  Make sure the circuit is working before wiring up stop switches and boxing.  At least this way you start with a working circuit, and if in the process of boxing it up new issues appear, it's not the circuit, it's off-board issues.

BREADBOARD
If you plan on building a few, buy a cheap breadboard and you can use this as a test platform.





snow123

Tbh I've just been using the multimeter to make sure all tracks and joints on the pcb are connected, and everything on the pcb doesn't seem to have any issues so I'm thinking the main issues could be is how the 1/4' jacks, dc jack, and footswitch are wired.

snow123

Also, I should note that when I have the pedal turned on, it sound like half the the effect is going through, making me think that there might me something wrong in between the input/output jacks, pcb and (maybe) footswitch.

andy-h-h

Quote from: snow123 on May 01, 2021, 05:13:12 AM
Also, I should note that when I have the pedal turned on, it sound like half the the effect is going through, making me think that there might me something wrong in between the input/output jacks, pcb and (maybe) footswitch.

Which is exactly why you should strip it back to just the circuit and trace the signal with a probe. 

aelling

#148
Quote from: snow123 on May 01, 2021, 05:06:14 AM
Tbh I've just been using the multimeter to make sure all tracks and joints on the pcb are connected, and everything on the pcb doesn't seem to have any issues so I'm thinking the main issues could be is how the 1/4' jacks, dc jack, and footswitch are wired.
Test for continuity between tip and sleeve on the in/output jack with you multimeter, if it beeps it's shorting to ground somewhere.

EDIT: Also, the resistor on the footswitch shouldn't be needed, just a wire to the LED.

duck_arse

You hold the small basket while I strain the gnat.

snow123

Quote from: aelling on May 01, 2021, 09:23:22 AM
Quote from: snow123 on May 01, 2021, 05:06:14 AM
Tbh I've just been using the multimeter to make sure all tracks and joints on the pcb are connected, and everything on the pcb doesn't seem to have any issues so I'm thinking the main issues could be is how the 1/4' jacks, dc jack, and footswitch are wired.
Test for continuity between tip and sleeve on the in/output jack with you multimeter, if it beeps it's shorting to ground somewhere.

EDIT: Also, the resistor on the footswitch shouldn't be needed, just a wire to the LED.

i got a beep on the output jack.

snow123

Here's the front with the pots and stuff and how I have the footswitch wired if it helps at all




aelling

#152
Quote from: snow123 on May 01, 2021, 03:22:33 PM
Quote from: aelling on May 01, 2021, 09:23:22 AM
Quote from: snow123 on May 01, 2021, 05:06:14 AM
Tbh I've just been using the multimeter to make sure all tracks and joints on the pcb are connected, and everything on the pcb doesn't seem to have any issues so I'm thinking the main issues could be is how the 1/4' jacks, dc jack, and footswitch are wired.
Test for continuity between tip and sleeve on the in/output jack with you multimeter, if it beeps it's shorting to ground somewhere.

EDIT: Also, the resistor on the footswitch shouldn't be needed, just a wire to the LED.

i got a beep on the output jack.
I'm wondering if the tip on the jacks have been touching the walls of the enclosure, they look like they sit awfully close in this photo.
https://postimg.cc/688GVptF

Maybe put a little electrical tape inside so that can't happen.

antonis

Quote from: snow123 on May 01, 2021, 03:22:33 PM
i got a beep on the output jack.

But beep is tone and tone is sound.. :icon_wink:

P.S.
You've got beep when probing what 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


antonis

If so, you have a shorted output..

No signal can go further hence no output sound..
"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


aelling

Quote from: snow123 on May 01, 2021, 05:45:49 PM
how do i fix it tho?
The enclosure gets grounded by the jacks, so check if the tip of the jacks are touching anywhere on the inside once mounted.

snow123

somehow the 1st lug on the expand knob is grounded to the enclousure

snow123

wtf everything on the input jacks sleeve is grounded to the enclosure