TS808 pops when LED in, all other TS808’s fine?

[Kroars]

So, I’ve been scouring for the last couple days, read the AMZ article and combed through the forums. Found a lot of helpful tips and suggestions for solving this. My question is, what could cause switch pop when LED is engaged in a particular TS (the LGSM pcb) build, when all others have been fine?

I’ve replaced the electrolytic caps, testing prior to installation. All Nichicon from Mouser, aside from the 10uF output cap I used a Tantalum as an additional measure. I’ve replaced the foot switch with another Pro 3pdt from SBP. Reflowed all solder joints using a flux pen just to be sure. Still the problem persists.

Only pops when indicator LED is in the circuit. I could certainly add a cap and resistor as AMZ suggests. I’m just curious as to why that would happen in one build when the others work perfectly?

I haven’t replaced any of the film caps, but they’re all Wima MKS2’s from Mouser.

I can add photos later this evening. I was hoping someone could shed light as to how this happens with the indicator LED in particular.

Thanks!

 

[jimilee]

Nope, just my Rockerverb. I could try the TH30, I suppose. I’ve tried it through my RV with other TS808’s without issue.

Right, I’m curious if there is a leaky cap causing the issue. It seems like the pedal isn’t the problem.

 

[Kroars]

You definately got the listed 10K at R15, The pulldown resistor at the end as that is a known problem on plenty of circuits with 100K ???
10K - Brown, Black, Black, Red, Brown.

You hit the nail on the head for the TS! Of course, I dive into the Skeptical Buffer, replace every component and bypass the deep dive on the TS (the build with the available schematic). I’m gonna get that changed out and I’m sure it’ll take care of the issue. It was minor in the TS. The Skeptical Buffer is the one that had the loud pop.

Here’s the picture of the TS that I should’ve posted earlier, clearly showing the 100k at R15….

I’ll also include a picture of the Skeptical Buffer, the one that has really stumped me. This is the one that I took the time to swap out every component on the pcb.

Thank you so much for the help on the TS!

 

[music6000]

Awesome!, I had run out of possible causes!
This is why I listed this many moons ago as this sort of thing could be resolved earlier with this Picture

Important: Supplying Pictures when an Issue arises with a PCB Build !!!

I have to raise this ongoing issue when Members ask for Help with an Issue with their Build. I keep repeating this saying '' Pictures are worth a Thousand Words'' !!! Please supply Pictures of PCB & ALL connections ( Footswitch, Input & Output Jacks, Power Jack ) to it along with a clear...

forum.pedalpcb.com

 

[Kroars]

Awesome!, I had run out of possible causes!
This is why I listed this many moons ago as this sort of thing could be resolved earlier with this Picture

Important: Supplying Pictures when an Issue arises with a PCB Build !!!

I have to raise this ongoing issue when Members ask for Help with an Issue with their Build. I keep repeating this saying '' Pictures are worth a Thousand Words'' !!! Please supply Pictures of PCB & ALL connections ( Footswitch, Input & Output Jacks, Power Jack ) to it along with a clear...

forum.pedalpcb.com

Very true. Thank you very much.

 

[cdwillis]

So did you replace the 100k to ground with a 10k and that stopped the popping?

 

[Kroars]

So did you replace the 100k to ground with a 10k and that stopped the popping?

Yup, that was it. No luck on the Skeptical Buffer, though.