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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Ale_jellybelly said:
do I have the V1 board?
Click to expand...

It's the V1 circuit altogether, not the PCB specifically. In hindsight it probably should have been added anyway.

I'd add the resistor at the PCB like your first picture to avoid heating the 3PDT lugs any more than necessary.

I'm not sure that this is a common issue with the build or anything like that, it's just the first thing that came to mind after reading your problem.
 
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Ale_jellybelly said:
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
Click to expand...

You might start by disconnecting the LED and seeing if the pop goes away.
 
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nate433 said:
People smarter than me. If this is the case, is there anything design-wise in a pedal we can do to avoid it? Like are certain designs more or less likely to be affected by this? Or is it 100% the amps fault?
Click to expand...
If it's DC offset coming from your amp or your computer interface or whatever, you can try blocking it at the source. A dead/dying preamp tube in V1, for example, can be a bummer - could be an easy fix if that's the case. Lehle make a little utility box for just this purpose, you could try rolling your own and placing it between different part of your signal chain. Alternately, you could add always-on buffers to both ends of the pedalboard/etc and see if that solves the issue?

I know there's a schematic for the DC Filter floating around, but I can't seem to pull it up with a simple google search - iirc there's not much to it at all, just some simple R/C filtering.
 
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Robert said:
It's the V1 circuit altogether, not the PCB specifically. In hindsight it probably should have been added anyway.

I'd add the resistor at the PCB like your first picture to avoid heating the 3PDT lugs any more than necessary.

I'm not sure that this is a common issue with the build or anything like that, it's just the first thing that came to mind after reading your problem.
Click to expand...
ah yes thanks, got it. In the end I added it on the 3pdt but on the pcb would've been wiser
mdc said:
You might start by disconnecting the LED and seeing if the pop goes away.
Click to expand...
I did try it when I first built it but it didn't change the pop unfortunately
 
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Robert said:
Yep. Prototype is on the way.
Click to expand...
I’ve seen a what was supposed a schematic of v2 - the sag was completely different and only acting on one stage (like the ss/bs mini) - is that right from your version?

Oh and btw - thanks for the fix - I love this pedal I made on the PedalPCB pcb - but get bad looks from sound guys everytime I hit it and pop.
 
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