Pedal popping fixes??

[coachseeley]

Good evening,
I've used 3 different PCB manufacturers so far and I seem to encounter engagement popping with the majority of my PedalPCB builds (Modus Operandi, Transcendence, Arche, Shrapnel, Guardian, Magnetron, Spirit Box, Duocast, Ocelot, etc...). The circuits sound fantastic once they're on, but engaging a pedal in the middle of a song, and hearing that pop, is a bit of a nuisance.
I searched through some of the posts and I see that a 100k resistor on the output is a common fix - as well as switching to tantalum on some of the electrolytic caps.
Question is, "where is the best place to place the 100k resistor from output to ground?" Should I put it on the footswitch PCB? Do I need to go directly from the output pad on the main board?
Thanks for any help you kind folks can offer? I'm asking here because I'm not experiencing this issue with other PCB manufacturers. On some of the problematic builds, I've tried 3 different brands of 3PDT footswitch, soldered transistors instead of socketing them, put on some additional RPD, etc... I'm wondering if I'm building all of these pedal incorrectly. Thanks again. (Pic is the latest build - Guardian)

 

[coachseeley]

I’ve read that the last electrolytic capacitor in the circuit can cause issues…especially if it’s a cheap capacitor. They can hold a residual charge that can cause a pop when the switch is pressed. Need to look into this since I have quite a few that use tantalum instead of electrolytic.

Definitely looking into that. Thank you.

 

[andare]

I found this 3pdt wiring scheme which claims to eliminate all pops. Haven't tried it though. It requires removing any pulldown resistors.



Here's the full thread https://www.madbeanpedals.com/forum/index.php?topic=27743.0

 

[giovanni]

Iirc it adds a 470K pull down resistor on the output?

 

[jimilee]

Nobody has mentioned your amp, are you running through your amp? Does a buffered pedal before it fix it?

 

[zgrav]

Popping switches are sometimes mysteries unto themselves. My circulator pedal only stopped popping after I put in a soft relay switch. For this question it is odd that the popping only appears with some PPCB boards, but it may have more to do with the parts sourced for them at the time.

 

[mdc]

This worked for me when nothing else would. It's super simple...

VoodooLabs Optical Bypass

Hi folks This is a bit of a utility build report, but hopefully some others will find it useful? In any case, I've had a few builds lately with switch pop that wasn't cured through the usual methods. In digging around for a solution, I found the schematic for optocoupler-based bypass that...

forum.pedalpcb.com

 

[giovanni]

This worked for me when nothing else would. It's super simple...

VoodooLabs Optical Bypass

Hi folks This is a bit of a utility build report, but hopefully some others will find it useful? In any case, I've had a few builds lately with switch pop that wasn't cured through the usual methods. In digging around for a solution, I found the schematic for optocoupler-based bypass that...

forum.pedalpcb.com

I was looking for your post to share on this one!

 

[coachseeley]

Nobody has mentioned your amp, are you running through your amp? Does a buffered pedal before it fix it?

I'm using a simple Hotone solid state job on my work bench. It usually translates the same when using my HX Stomp or my little 6W 5F1 build I made.

 

[coachseeley]

Just disconnect the LED temporarily, if the popping continues swapping the color won't help.

When I took out the LED, the pop went away... therefore I proceeded to swap colors. First Ultra bright blue, then ultra bright red, then red diffused. They all popped the same. I even tried the Muzique method mentioned by tying in a 390R resistor and a 33uF cap to ground. It still pops...!!!! Next step might be to swap out the 4u7 caps for better quality ones.

 

[phi1]

No need to change those two, C11 is responsible for blocking all the DC to the output. Strange that the RC filter on the led didn’t fix it even though removing the led did.

 

[coachseeley]

No need to change those two, C11 is responsible for blocking all the DC to the output. Strange that the RC filter on the led didn’t fix it even though removing the led did.

That’s what I was thinking and saw that it was already film and 1uF.

 

[Robert]

Try an ultra bright LED with a higher value current limiting resistor.

 

[coachseeley]

This worked for me when nothing else would. It's super simple...

VoodooLabs Optical Bypass

Hi folks This is a bit of a utility build report, but hopefully some others will find it useful? In any case, I've had a few builds lately with switch pop that wasn't cured through the usual methods. In digging around for a solution, I found the schematic for optocoupler-based bypass that...

forum.pedalpcb.com

This is great!!
How would I use this with a PPCB board? They have the standard 4 pads at the bottom and the 2 pads for LED?

 

[coachseeley]

Try an ultra bright LED with a higher value current limiting resistor.

Awesome! Which draws less current, super bright or ultra bright? Are we talking doubling the value of CLR or even do something huge like 50k?

 

[giovanni]

Awesome! Which draws less current, super bright or ultra bright? Are we talking doubling the value of CLR or even do something huge like 50k?

It depends how bright you want it to be. 4.7K will blind you. Breadboard to find your favorite value. I would start from 10K.

 

[andare]

Iirc it adds a 470K pull down resistor on the output?

Yes looks like that's what it does

 

[music6000]

Can you try this:
10K Resistor Output to Ground.

 

[mdc]

This is great!!
How would I use this with a PPCB board? They have the standard 4 pads at the bottom and the 2 pads for LED?

I'd remove the LED from the PCB; wire power and ground from the DC jack to the PCB as usual; omit the LED connection to the footswitch from the PCB; then wire everything else as shown in the diagram. If you're not familiar with vero builds this would be a pretty easy one to start with.

 

[coachseeley]

Can you try this:
10K Resistor Output to Ground.
View attachment 26071

Will do. When I first looked at the image on my phone I thought, dang... that's clean. Seeing it on my computer... photoshop?

 

[coachseeley]

Will do. When I first looked at the image on my phone I thought, dang... that's clean. Seeing it on my computer... photoshop?

Much more tolerable... This pedal will be part of my base tone - and I think I can get away with the minimal pop. Thank you.