Weirdest noise problem ever

[nordine]

Hey there,

ive been fighting this noise issue all morning, but before i give up, i shall ask you fellow pedal builders  

it goes like this:

I had a bbe sonic maximizer clone that has worked well for about a year in a small box. i decided to put it in a bigger box (hammond type, but bigger). I turn it on and get this nasty white noise burst type noise (the kind of noise one hears in a camcorder when wind hits it hard), the effect is still there, but theres this unbearable noise over it.

troubleshoot:
-i tested it outside the box and worked fine. then i boxed it and it worked as said (noisy as f**k)
-pulled it out, tested it outside the box, no problem at all.
-power source is fine, tested other pedals and no noise at all.
-type of power source aint the problem, tested it with a fresh battery and i get the same noise
-get a load of this: tested it switchless (wired directly to the jacks), and without power jack (directly too), ground is wired btw, still getting noise
-i pull the audio jacks out of the box and then the noise ceases.



ive isolated everything, it CANT be the box can it? pls help  

edit: ive leant to guess what could be causing trouble in different scenarios... and this could be only explained by some kind of diode getting on the way, its total diode configuration/transistor type noise... but i just cant see how the box can add that 

[nordine]

Got it, was a faulty pot, first time an alpha pot fails on me, this one had the casing touching internally one of its lugs 

[Mark Hammer]

This is precisely why over the last few years I have taken to the practice of slipping a piece of shrink tubing over the solder joints/lugs on pots so that any exposed parts that might short are covered.  That also includes unused lugs.

If it was the case that I popped holes in the chassis for the little stabilizing tongue that sticks out the shaft side, that would be one thing.  If it was the case that I never put more than 2 pots in a 1590B or 3 in a 1590BB, that would be another.  Or if it was the case that holding a pot in place from the inside of the chassis while you tighten the nut from the outside meant that it would never ever ever move from that spot, that would be yet another.

But all too often I put as many controls in the box as the knob diameter permits, don't use locking washers or the stabilizing tongue to secure, and the pots end up too darn close to: other pots, the chassis walls, toggles, jacks, and vertically mounted resistors with exposed leads.  A few turn-it-ups and turn-it-downs, and before you know it, the pot has rotated a bit and the lugs are touching something they shouldn't.

You have my sympathies.  I've been there so often, it counts as my other mailing address.