Three Skeptical Buffers, three switches popping

[Kroars]

I really hate to do this. I recently had an issue with a TS808 popping, that @music6000 kindly pointed out that I had an incorrect resistor installed. In that thread I had mentioned that I had a Skeptical Buffer doing the same thing. After replacing the usual suspects for leaky caps (all checked out, but replaced anyway), I went one by one replacing every component on the pcb, including footswitch, all jacks and wiring.

I ended up ordering two more Skeptical Buffers, just finished them and they pop as well. One a lot louder than the other. I’m hoping someone can spot something that I’m missing or suggest a fix. Here are the three SB’s that are popping. I suppose I can Orman’s fix with the additional resistor and capacitor at the LED, but I’ve got to be missing something here.

Robert mentioned in one thread about a Cobalt popping “2M doesn't allow any DC bias to discharge from the 10uF capacitor quick enough”. I wonder if there is a similar issue with the 3M3 prior to output? I don’t see a schematic posted for this, though.

Thank you very much for any help.

 

[Kroars]

Are you using the same type LEDs in them all? Pull one leg of the LED and see if it changes the pop..

Oh, it’s definitely related to the LED. Problem is, doesn’t matter which color or brand. Not too mention the same LED’s, as well as other components/switches/jacks etc have been used in numerous other builds without issue.

 

[KR Sound]

Next time I run across one, I want to try the footswitch breakout board with the led and resistor/trim pot together. I wonder if removing it from the board and placing it in another location will alleviate it. Maybe, maybe not.

 

[Kroars]

Next time I run across one, I want to try the footswitch breakout board with the led and resistor/trim pot together. I wonder if removing it from the board and placing it in another location will alleviate it. Maybe, maybe not.

At this point, I’m open to any further suggestions. This is really a weird one. Dozens of pedals built between these five, all with the same component batches -not a hint of a pop on any of them. Not to mention the few successful SB’s I built before these 5. Although, those were purchased and built months before the infamous five.

 

[benny_profane]

Oh, it’s definitely related to the LED. Problem is, doesn’t matter which color or brand. Not too mention the same LED’s, as well as other components/switches/jacks etc have been used in numerous other builds without issue.

Check out the examples here.

 

[Kroars]

Check out the examples here.

I had mentioned those previously. I’d rather find the culprit. Seems to me, if I had built a handful of these successfully prior to the five, with the same batch of components (not to mention dozens of other pedals) it should be something we could narrow down. It doesn’t make sense to me why all five in a row would present the same exact problem.

Hell, on one of the pcbs, I replaced every single component, jacks switches wiring -everything but the pcb. Fired right up, but popped like the best of em. All my components are pre-tested prior to installation. No leaky caps. Three different brands of footswitches, even a Gorva.