SOLVED Chop shop popping when activated + squealing even in bypass

Ale_jellybelly

Ale_jellybelly

Well-known member
Hi all
First PPCB build, the lovely Chop Shop.
Biased the J201 without problems thanks to the threads in here, sounds great, boxed it up and it pops quite loudly when pushing the 3pdt.
Anything obvious that I'm missing? R1 should be the pull down resistor right? Looks fine to me

IMG_20230523_182631.jpg
 
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Try pulling the LED and see if that's the culprit.
Alternately, it could be DC leaking in from whatever you happen to be plugging into.
 
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mdc said:
Try pulling the LED and see if that's the culprit.
Alternately, it could be DC leaking in from whatever you happen to be plugging into.
Click to expand...
Tried two different power supplies, no difference.
Unsoldered the LED, reflowed R1 and it still pops
jhaneyzz said:
Hmmmm… it’s only got like 12 parts and I looks ok.

Other than the popping, does it work as expected?
Click to expand...
It works very well, sounds great, biased both J201s at 6v
 
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Sorry, by "whatever you happen to be plugging into" I meant your amp or computer etc.

What happens when you place a buffered bypass pedal before or after the chop shop?

What happens when you keep everything constant and swap the pedal out for a different overdrive with mechanical true bypass switching?
 
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mdc said:
Sorry, by "whatever you happen to be plugging into" I meant your amp or computer etc.

What happens when you place a buffered bypass pedal before or after the chop shop?

What happens when you keep everything constant and swap the pedal out for a different overdrive with mechanical true bypass switching?
Click to expand...
Ah I understand
I tried it straight into my solid state fender amp. It's the only DIY pedal that does it.
Later today I'll try putting it in the chain with a buffered pedal
RetiredUnit1 said:
Single pop or multiple randomly spaced pops, like static? If it's only one pop, then it sounds like the foot switch may be faulty, or a cold solder.
Click to expand...
It's a single pop, could be a cold solder yeah, I've had some trouble lately managing to fit wires in the board. I'll check better. Hopefully not a faulty switch
 
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Ale_jellybelly said:
Ah I understand
I tried it straight into my solid state fender amp. It's the only DIY pedal that does it.
Later today I'll try putting it in the chain with a buffered pedal

It's a single pop, could be a cold solder yeah, I've had some trouble lately managing to fit wires in the board. I'll check better. Hopefully not a faulty switch
Click to expand...
I was also thinking, capacitors are often used to suppress switch popping, could be a bad cap or circuit incompleteness due to solder, design or board fault
 
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Ale_jellybelly said:
Thanks, I'll try reflowing it during the weekend
Click to expand...
well the weekend at the end of may became the 31st of August because summer and scorching heat in Italy happened
I opened it up, redid a bit of the footswitch wiring, resoldered the LED because the soldering was terrible
It still pops so I'm gonna take off the board and check for cold solders
In the meantime I noticed that even if it sounds great, if I put the SAG and DRIVE knobs all the way up, the pedal squeals, and worse of all, I can hear the squealing (even if at a much lower volume) even when the pedal is bypassed.
From what I've read around here, squealing is often because of a bad-ish JFET...
I don't think my wiring is this bad, but squealing on bypass can only mean bad wiring right? Or maybe a bad footswitch?
 
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3PDT Continuity Test.jpg

With no power connected, test for Continuity.
OFF
2....5....8
v....v.....v
3....6....9
ON
1....4....7
v.....v....v
2....5....8
You should not have continuity with:
1 & 4
2 & 5
3 & 6
4 & 7
5 & 8
6 & 9
If you do, you have a short!
 
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Mcknib said:
Try reflowing C100 the 220u filter cap

Griffin effects covers a few potential causes here

Why is my guitar pedal popping? - Griffin Effects

griffineffects.com griffineffects.com
Click to expand...
Did it, no change unfortunately
mdc said:
Sorry, typo - I meant you might’ve cooked the 3pdt stomp switch.
Click to expand...
Going to try and swap it when I get the chance
music6000 said:
View attachment 55645

With no power connected, test for Continuity.
OFF
2....5....8
v....v.....v
3....6....9
ON
1....4....7
v.....v....v
2....5....8
You should not have continuity with:
1 & 4
2 & 5
3 & 6
4 & 7
5 & 8
6 & 9
If you do, you have a short!
Click to expand...
My shitty DMM doesn't have a continuity tester but tried it with resistor tester and looks like there is no continuity. I hope to solve the popping with a new 3pdt
But the squealing isn't going away :(
 
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