What can I about unwanted crackling? What is the cause?

[RjM]

I can barely hear the crackling with just the sparkleboost on, but with my distortion on, you can hear it too much. What are some causes of crackling? Even when the effect is bypassed, there is crackling. Can toggle switches be heat damaged by soldering irons? How could I pinpoint this? I suppose I could just go around and re-solder weak-looking connections.

[Paul Perry (Frostwave)]

I guess you have wiggled everything & tried tapping everything with a screwdriver handle.
I think it is possible to have a sealed switch 'go bad' while eing soldered, by the heat melting lubricant inside the switch & getting it over the contacts. You can test if that is it, by temporarily bypassign the switch contacts with alligtor leads & seeing if it still crackles (no need to unsolder the switch).