Need a FAST answer

[vendettav]

Hey guys. I built this little true-bypass box.
It's in a plastic box. It's got cables going out of it with jacks (not female jacks). The cables are dual core, one is used for hot, one is the ground (but it's not shielded, just two wires going parallel)

and the issue: it hums! I'm gonna try and shield it with aluminum foil now but the question is, do you think it's cause of the stupid cable (which I guess is not an instrument cable by any means) or the box that is plastic? I thought it'd be the cables cause the box itself has only a switch and that's it. Ideas?

[Mike Burgundy]

Anything that's not shielded is susceptible to noise pick-up. That said, as long as you're not near fluorescent lighting, power station and/or a large server/switch room, short distances might be ok. It is also very possible you have ground loop issues.
I'd say use a shielded box AND shielded cables, then deal with groundloops if need be (have a look at GEO). Unshielded stuff *will* create problems somewhere down the line.

[deadastronaut]

stick it in an old tin...and see the difference...

[vendettav]

hmm it's just gonna take me awhile to get shielded cable, and for the box, I'll have to shield it with foil cause I can't find a metal box here I need this box soon ugh!

[vendettav]

also tell me about aluminum shielding. should it go into every single corner or.. ?

[Gurner]

To find out if it's a shielding issue *fast* - wrap your board in paper (kitchen roll whatever - just to protect it from shorts), now totally wrap it in aluminium kitchen foil (taking care not to pronounce it aloom-in-um, which is quite wrong) ground the foil via a flying croc clip to your signal ground point - you've an instant answer as toi whether your hum is to do with shielding  (total time about 1 minute)  ....if it can't be deboxed quickly, then just wrap kitchen foil around your present enclosure....ground the foil - instant answer again. If I were a betting man, I'd say the hum you're experiencing is not likely to be shiedling...but more bad grounding arragements.

[deadastronaut]

glue a sausage roll to the top of your head , then walk bolt upright in a tight circle around your room for 3:47....

the sausage roll will act like a receiver and magically suck any stray interference from your box....

it won't get rid of noise, but it will be funny....

[markeebee]

Um.



Has anybody got some of that stuff that dissolves glue?

[newfish]

Hot Glue really hurts! 

As for the aluminium foil, I'd say get as far into the corners as you can without tearing the foil.

The main thing is to have a good connection to your signal ground - and watch out for shorts!

[DavenPaget]

Hot Glue really hurts! 

As for the aluminium foil, I'd say get as far into the corners as you can without tearing the foil.

The main thing is to have a good connection to your signal ground - and watch out for shorts!

Amazingly they hurt way more then SOLDER !
Because of the mass you usually squeeze out , and it transfers the heat slowly since it isn't metal ._.
I had a hot glue accident on my thumb before , I COULDN'T do any writing or any thing that needs my pilot thumb

[vendettav]

ok here's another question, when I put my finger on the cable it changes the hum sound, (even tho I dont touch the wires physically) and the same is even when I put my finger close to the cable. guess it's the cable...?

[Maik]

Interferences, magic?
Get rid of those cables!
Or put the other finger out of the lamb. 

[vendettav]

^ 

I already got new cables yay, gonna solder them in the evening