Pedal crackling even with no power connected / bypassed ? ?

[steveyraff]

Ahoy all,

Got an email today from a guy I built a pedal for recently. Its a variable Meathead Fuzz and Fox ToneMachine 2-in-1 dealio.

When it left here, it sounded fine to me when I tested it. He said he tried it out when it arrived and everything is working fine except there is intermittent crackling noises. The peculiar thing is that he said the crackling is even there when the power is disconnected from the pedal.

I did a few obvious checks first. He swapped out all his cables, tried different guitars, different power supplies etc. I asked him to remove the backplate incase one of the circuits became dislodged in the mail and was now touching something it shouldn't be. It all looked fine in there, and I've everything completely covered with electrical insulation tape anyway.

He has tried using different pedals, different power supplies. It seems to be just my pedal, and its crackling in bypass mode and even when the power is disconnected from it.

Anyone heard of this before or what it could be ??

EDIT: Here is a video he sent me. I am having a hard time figuring out which noise he means. He says cracking in the description. I hear tapping, which i think might be background noise. Maybe he means the "wurring" noise? What y'all think?
https://www.dropbox.com/s/zympnrwgxp7jrel/20190830_165920.mp4?dl=0

[antonis]

First suspect should be IN (or OUT) jack..
(then should come 3PDT switch..)

[steveyraff]

First suspect should be IN (or OUT) jack..
(then should come 3PDT switch..)

My thoughts too

[steveyraff]

Very difficult to communicate as he is a different language - but I think he is saying that the tapping noise and the wurring noise happens as soon as the power cable is connected to the pedals DC jack - even if the power is switched off or on at the actual outlet.

Could this still be the jacks or 3PDTs ? ?

[antonis]

Hmmmm...

It seems to me like a loose nut on jack GND..

[steveyraff]

its very hard to tell, but I think he means that it is happening only when the power cable is connected.

https://www.dropbox.com/s/8t835krza71lkib/20190830_172543.mp4

[steveyraff]

Ya know what. I think I see the problem. He sent me a photo of the inside of the pedal. It doesn't show much, but already I can see that on the output jack, there is only one wire going from the ground lug, and there are TWO soldered to the tip lug. The meathead has a ground cable going from its potentiometers 1st pin, to the ground lug. I think I may have stupidly ran a cable from the pots ground lug, to the output jacks tip lug. I've been working at pedals 12 hrs a day lately. I was going to do something stupid eventually. He is going to have a look at it for me, I'll report back...

DOH!