troubleshooting Katzenkoenig

[cnspedalbuilder]

Hi, after a great streak of builds, I went into a slump of a few consecutive duds. I'm now trying to dig my way out 

This one is a clone of the Catalinbread Katzenkoenig.
From what I have read it is a cross b/w a silicon tonebender and a Rat. Should have been an easy build, right? PCB is from Rullywow, and build doc, schematic, etc. are here: https://rullywow.com/wp-content/uploads/2016/01/Princess-Rawr-v1.pdf

The pedal works but it produces a very crackly, fizzy sound. If the input gain is cranked up it sounds ok though you can still hear the loud fuzzy crackling. If input gain is down it sounds flaccid and crackly. This isn't like the demos that I have seen of the pedal, so I must be doing something wrong.

I know that the tone/filter and volume pots work as intended, and it looks like changing the input and output gain produces effects. Since it is producing sound, I'm not exactly sure where to start in terms of troubleshooting, voltages, etc.

I'd appreciate any input y'all may have. Gut shot below, thanks!
p.s. after taking the photo, I reflowed solder at the pots, and it's all good there.

[antonis]

Check for shorted C1 (68nF) input cap..(circled red)
(or for a veeeery leaky one..)

(particurally for fizzines, I'd also suspect C3 (47pF, circled green) or I'd raise its value to 100pF..)

[cnspedalbuilder]

Antonis, thank you, I found the short, fixed it, and it sounds great now!

On to the next troubled project!

[antonis]

On to the next troubled project!

As far as it's one at the time, plz keep going..

[cnspedalbuilder]

Hello, maybe I am being a perfectionist, but I think I have another problem. I noticed that I get no noticeable changes when I turn the gain pot. The Input pot is fine and can change the sound significantly, but not the Gain. I pulled out the guts and found that between lugs 1 and 3 I only get 7K resistance, despite the fact that it is a 250k pot. It's configured as a variable resistor in the schematic, so I made sure to set it so resistance should be maximum. Could this mean that the pot is bad? I know soldering can mess up the pot, but it seems odd that somehow the pot could get so screwed up that the resistance goes down by that much. Thoughts?

[willienillie]

I would expect a pot to go open, or higher resistance, if damaged by soldering.  Maybe there's a splash of solder or a lead clipping that got inside and is partially shorting the track.  Or maybe it was just a bad pot to begin with.  Either way, just replace it.  I've been intending to build that circuit for some time now, the demos sound great.

[cnspedalbuilder]

Thank you, I started wiggling around the pot and then lo and behold, the resistances came back to normal. Fired it up and gain is now working. I don't know what happened, but it must've been a mechanical issue in the pot from being squished in the box. I feel like I should replace it, but it's so hard to desolder pots on a tight board like this and right now it aint broke, so I'm moving on to the next problem pedal...