Pedal Humming on Floor Level - HELP

Started by victorbignacio, May 04, 2017, 07:24:27 PM

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victorbignacio

Hey Guys,
I built 2 pedals, in wooden enclosures, and it turned out great. But as soon as I put them on floor, or floor level, it starts humming, like it had a bad ground or something, and whenever I put it on the cab or even above other pedal, it stops humming.
Does anyone know why this happens, I dont think its the wooden enclosure because I have friends that build ''wooden pedals'' and they sound great, anyway.
Thanks

blackieNYC

Is the wooden box lined with aluminum foil or copper tape ? And grounded? If not, it might respond noisily to RF/EMI fields based on its positioning.  Or maybe one of your other pedals is interfering with it?
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Alex83tele

The only thing I'm aware of that will introduce noise in a circuit based on physical position is EMI through the air. Obviously, no one can really point to the source of a noise by reading about it,  but shielding electronics, like the previous post mentions, is good practice. If you do it properly, it will probably clear up the noise, but the interference we're referring to is messy and ever present. Usually these waves are too weak and scattered to produce a cohesive tone, even in an unshielded device. At the same time, give the right frequency and amplitude, they could pass right through shielding like it wasn't there. The good news is, shielding your enclosures won't be a waste of your time. It will block plenty of noise, but it's a thankless job since we don't hear it working.


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stallik

Don't forget what's under the floor. My man cave is above my garage. If the fluorescent tube is on in the garage, it really shows up any weaknesses in my shielding especially with distortion effects. Hardly surprising since the tube is only about a foot away from the pedal
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antonis

Unshielded enclosure messing with hum usually indicates mains cables hanging around... :icon_wink:
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anotherjim

Here in the UK it's usual for AC wiring for wall sockets and lights to be run in the void between ceiling and upper floor. Rarely done under a ground level floor because of the higher chance of flooding or rodents. If not on the ground floor, there is a very good chance there are lighting cables just below the floor cladding.
 

Ben Lyman

wrap the whole box tightly in tin foil and put it on the floor.. see if it stops the noise
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victorbignacio

#7
Ok, so to shield it, I need to wrap the inside in copper tape and connect it on the ground of any jack?

Ben Lyman

You can also use conductive shielding paint. It's about $20 for 2 ounces on a couple of sites but a little goes a long way, certainly do a 5 or 6 pedals with it.

But I'm serious about testing with a tin foil wrap first. Just so you know if that's it
"I like distortion and I like delay. There... I said it!"
                                                                          -S. Vai

GibsonGM

Quote from: victorbignacio on May 05, 2017, 09:55:14 PM
Ok, so to shield it, I need to wrap the inside in copper tape and connect it on the ground of any jack?


You can "plate" the entire inside (bottom too) with aluminum foil, connect it to ground by whatever means, and you will likely find that you have much less interference.  You don't need copper.   But each piece of Al foil must be electrically connected to the next, is all.  Not rocket science, and should not cost you more than a few dollars. 

Do not worry that you need a hole to put a pot through, just make the hole, it is ok...small openings like that will not cause much harm. You want a wrapper, tied to ground, with a few holes in it that pots and jacks fit thru.  Then noise and junk will LIKE that more than your circuit ;)
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victorbignacio

Ok, just shielded it and... NO HUM!
Thanks for the help my friends!